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	2022-12-08: How Are Quasiparticles Different From Particles? 00:12: But the only elementary particle actually flowing in the circuit are the negatively charged electrons. 00:53: Now electrons, which are regular particles, are pushed around inside electrical circuits, but it’s only half the story. 01:08: Let’s look at the material that is central to all modern electronics - silicon. 01:14: The silicon atom has 4 electrons in its outer or valence shell. 01:19: Atoms are most stable with full valence shells, which means 8 electrons. 01:38: These electrons are locked in place in the now-full valence energy level. 01:44: ... vibrations or in the case of solar cells by a photon, at which point the electron is free to move from atom to atom - for example if pulled by a voltage ... 02:02: Meanwhile, the gap left by this electron allows some movement in the valence shell. 02:08: A neighboring electron can move there, and its neighbor can fill t he new gap, etc. 02:13: It looks like the hole moves around, and under a voltage the hole moves in the opposite direction to the flow of electrons. 02:21: This is our first quasiparticle - it’s an electron hole. 02:25: It has an effective positive charge due to the charge of the nucleus not being properly canceled by electrons in that location. 02:53: They consist of two layers of silicon - on one side there’s an excess of valence electrons, and in the other a deficit. 03:07: On one side we sprinkle the silicon lattice with a tiny number of atoms that have 5 rather than 4 valence electrons. 03:16: Those extra electrons are more free to move around because they aren’t part of the crystal bonds. 03:27: The other side is doped with atoms that have 3 valence electrons - frequently boron. 03:32: ... electrons on that side can move a little bit. They can shuffle to fill the gaps in ... 03:48: ... the p-n junction, extra electrons in the n-type diffuse into the gaps in the p-type so we end up with a ... 04:00: ... a voltage in one direction and the holes and electrons flow away from this junction, expanding the non-conductive region and ... 04:09: ... apply the voltage the other way and the electrons and holes are driven towards the junction, causing it to narrow and ... 04:33: You might argue that electron holes are just a convenient way of looking at things, but that they aren’t “real” like electrons are. 04:40: After all, if you melt the silicon the electrons still exist but the holes don’t. 05:10: We have one quasiparticle from making a gap in one spot in the electron energy level. 05:55: Those vibrational modes in the crystal are quantized, similar to electron energy levels. 07:00: Compare that to electron holes, which are fermion-like in that you can only have one in a given spot at one time. 07:56: ... example, electrons traveling through a circuit encounter resistance - basically, they have ... 08:40: ... for example an atom is composed of quarks forming a nucleus and electrons bound to that nucleus by the exchange of virtual ... 09:33: ... much better conductors because they don’t use up all of their valence electrons in the bonds of the ... 09:43: Add a voltage and those electrons are free to travel through the structure as an electrical current. 10:03: ... Electrons are jostled, exchanging phonons in both directions with the atoms, which ... 10:39: In this case a quasi-force that can actually bind electrons together. 10:44: Normally we think of electrons as repelling each other via the electromagnetic force - mediated by photons. 10:50: At the same time, the negatively charged electrons in a metal lattice attract the positive nuclei. 10:57: ... nuclei get tugged a tiny bit in the direction of a free-moving electron, and that tiny increase in positive charge can in turn attract more ... 11:07: Ideally that first electron is part of an electric current, so it moves along. 11:15: ... take a little of the original electron’s energy in a vibration that’s part of a phonon, mixed up and ... 11:26: ... electrons that were attracted by this momentary convergence of positive charge are ... 11:47: ... stream of electrons in one direction sets up a sort of resonance in the vibrational modes of ... 11:56: In a very real way, these are electrons bound by phonons , and our next quasi-particle - the Cooper pair. 12:16: The pairs of electrons are bound over large distances, not separated by single atoms. 12:21: And it’s not simple to say which electron is bound to which other. 12:37: Each electron is spin half, making them fermions, but two electrons have spin 1 - like a photon and that's for reasons we can’t get into. 12:54: In fact at very low temperatures all of the pairs in an enormous network of flowing electrons can all occupy the lowest energy state. 14:20: After all, the elementary particles like electrons, photons, and quarks are just excitations in the elementary quantum fields. 14:32: Another field could be the number of electrons in the valence shell of a block of silicon. 14:47: A crystal lattice supports many fields - the quantized number of valence electrons, or the many quantized vibrational modes in its bonds. 05:10: We have one quasiparticle from making a gap in one spot in the electron energy level. 05:55: Those vibrational modes in the crystal are quantized, similar to electron energy levels. 05:10: We have one quasiparticle from making a gap in one spot in the electron energy level. 05:55: Those vibrational modes in the crystal are quantized, similar to electron energy levels. 02:21: This is our first quasiparticle - it’s an electron hole. 03:32: ... the underfilled valence shells - so we have flowing positively charged electron holes and a p-type ... 04:33: You might argue that electron holes are just a convenient way of looking at things, but that they aren’t “real” like electrons are. 07:00: Compare that to electron holes, which are fermion-like in that you can only have one in a given spot at one time. 01:08: Let’s look at the material that is central to all modern electronics - silicon. 00:12: But the only elementary particle actually flowing in the circuit are the negatively charged electrons. 00:53: Now electrons, which are regular particles, are pushed around inside electrical circuits, but it’s only half the story. 01:14: The silicon atom has 4 electrons in its outer or valence shell. 01:19: Atoms are most stable with full valence shells, which means 8 electrons. 01:38: These electrons are locked in place in the now-full valence energy level. 02:13: It looks like the hole moves around, and under a voltage the hole moves in the opposite direction to the flow of electrons. 02:25: It has an effective positive charge due to the charge of the nucleus not being properly canceled by electrons in that location. 02:53: They consist of two layers of silicon - on one side there’s an excess of valence electrons, and in the other a deficit. 03:07: On one side we sprinkle the silicon lattice with a tiny number of atoms that have 5 rather than 4 valence electrons. 03:16: Those extra electrons are more free to move around because they aren’t part of the crystal bonds. 03:27: The other side is doped with atoms that have 3 valence electrons - frequently boron. 03:32: ... electrons on that side can move a little bit. They can shuffle to fill the gaps in ... 03:48: ... the p-n junction, extra electrons in the n-type diffuse into the gaps in the p-type so we end up with a ... 04:00: ... a voltage in one direction and the holes and electrons flow away from this junction, expanding the non-conductive region and ... 04:09: ... apply the voltage the other way and the electrons and holes are driven towards the junction, causing it to narrow and ... 04:33: You might argue that electron holes are just a convenient way of looking at things, but that they aren’t “real” like electrons are. 04:40: After all, if you melt the silicon the electrons still exist but the holes don’t. 07:56: ... example, electrons traveling through a circuit encounter resistance - basically, they have ... 08:40: ... for example an atom is composed of quarks forming a nucleus and electrons bound to that nucleus by the exchange of virtual ... 09:33: ... much better conductors because they don’t use up all of their valence electrons in the bonds of the ... 09:43: Add a voltage and those electrons are free to travel through the structure as an electrical current. 10:03: ... Electrons are jostled, exchanging phonons in both directions with the atoms, which ... 10:39: In this case a quasi-force that can actually bind electrons together. 10:44: Normally we think of electrons as repelling each other via the electromagnetic force - mediated by photons. 10:50: At the same time, the negatively charged electrons in a metal lattice attract the positive nuclei. 10:57: ... and that tiny increase in positive charge can in turn attract more electrons. ... 11:15: ... take a little of the original electron’s energy in a vibration that’s part of a phonon, mixed up and ... 11:26: ... electrons that were attracted by this momentary convergence of positive charge are ... 11:47: ... stream of electrons in one direction sets up a sort of resonance in the vibrational modes of ... 11:56: In a very real way, these are electrons bound by phonons , and our next quasi-particle - the Cooper pair. 12:16: The pairs of electrons are bound over large distances, not separated by single atoms. 12:37: Each electron is spin half, making them fermions, but two electrons have spin 1 - like a photon and that's for reasons we can’t get into. 12:54: In fact at very low temperatures all of the pairs in an enormous network of flowing electrons can all occupy the lowest energy state. 14:20: After all, the elementary particles like electrons, photons, and quarks are just excitations in the elementary quantum fields. 14:32: Another field could be the number of electrons in the valence shell of a block of silicon. 14:47: A crystal lattice supports many fields - the quantized number of valence electrons, or the many quantized vibrational modes in its bonds. 03:27: The other side is doped with atoms that have 3 valence electrons - frequently boron. 08:40: ... for example an atom is composed of quarks forming a nucleus and electrons bound to that nucleus by the exchange of virtual ... 11:56: In a very real way, these are electrons bound by phonons , and our next quasi-particle - the Cooper pair. 11:15: ... take a little of the original electron’s energy in a vibration that’s part of a phonon, mixed up and indistinguishable ... 07:56: ... have collisions, which can be electromagnetic interactions with other electrons, falling into a hole, ... 04:00: ... a voltage in one direction and the holes and electrons flow away from this junction, expanding the non-conductive region and ... 04:09: ... and holes are driven towards the junction, causing it to narrow and electrons hop across, enabling the flow of ... 14:20: After all, the elementary particles like electrons, photons, and quarks are just excitations in the elementary quantum fields. 07:56: ... example, electrons traveling through a circuit encounter resistance - basically, they have ...
	2022-11-23: How To See Black Holes By Catching Neutrinos 01:16: ... and neutrino's fermion type is lepton, so they're cousins of the electron, muon and tau ... 03:38: ... can transmute the neutrino into its high-mass lepton counterpart - an electron, muon or ... 03:50: ... the neutrino becomes a tau then it decays almost instantly, but an electron or muon will continue through the ice, emitting light as it interacts ... 04:17: ... neutrinos are not slowed down, so the electron or muon that it creates also start out with a speed faster than the ... 05:11: In this way, IceCube sees the Cherenkov radiation from neutrinos generating both electrons and muons, but it’s the muons that are really useful. 05:23: ... Electrons interact very strongly with the water molecules and so begin to bounce ... 01:16: ... and neutrino's fermion type is lepton, so they're cousins of the electron, muon and tau ... 03:38: ... can transmute the neutrino into its high-mass lepton counterpart - an electron, muon or ... 05:11: In this way, IceCube sees the Cherenkov radiation from neutrinos generating both electrons and muons, but it’s the muons that are really useful. 05:23: ... Electrons interact very strongly with the water molecules and so begin to bounce ...
	2022-11-16: Are there Undiscovered Elements Beyond The Periodic Table? 01:38: ... that chemical properties depend on the number of outer shell or valence electrons, which increase by one every time you add a proton to the nucleus, until ... 04:50: ... one of its excess neutrons to transform into a proton after ejecting an electron and a neutrino, which transmutes it into ... 08:39: We have to think of these nucleons as having energy levels, just like electrons do. 08:45: You may remember the Octet Rule from your chemistry classes: If an electron shell has eight electrons it is stable. 08:52: That's the reason the Noble Gasses don't interact with anything, because their electron shells are already complete. 09:23: The magic numbers are all even, and that’s because nucleons pair up according to their quantum spin, just like electrons in their shells. 08:45: You may remember the Octet Rule from your chemistry classes: If an electron shell has eight electrons it is stable. 08:52: That's the reason the Noble Gasses don't interact with anything, because their electron shells are already complete. 01:38: ... that chemical properties depend on the number of outer shell or valence electrons, which increase by one every time you add a proton to the nucleus, until ... 08:39: We have to think of these nucleons as having energy levels, just like electrons do. 08:45: You may remember the Octet Rule from your chemistry classes: If an electron shell has eight electrons it is stable. 09:23: The magic numbers are all even, and that’s because nucleons pair up according to their quantum spin, just like electrons in their shells.
	2022-10-26: Why Did Quantum Entanglement Win the Nobel Prize in Physics? 06:33: ... light excited electrons in calcium atoms to higher energy level and they would then drop ... 06:42: ... of the possible electron transitions was between two states that had zero quantum spin, and ... 06:33: ... light excited electrons in calcium atoms to higher energy level and they would then drop ...
	2022-10-19: The Equation That Explains (Nearly) Everything! 06:02: ... Fermions, and they are stuff, literally, they are what stuff is made up. Electrons, quarks, neutrinos, they are all just different kinds of fermions. ...
	2022-10-12: The REAL Possibility of Mapping Alien Planets! 19:23: ... Well yes! The fine structure constant is defined as the electron charge squared divided by 4pi time   the vacuum permittivity ...
	2022-09-28: Why Is 1/137 One of the Greatest Unsolved Problems In Physics? 01:34: As with much of quantum mechanics, it started  with us watching the light produced as electrons flicked between energy levels in atoms. 02:36: ... still-new relativity, as well as the fact that the energy levels of electrons with opposite spins are separated slightly by their interaction with ... 02:55: ... multiple of one particular  number: the square of the charge of the electron, divided by four times pi, the permittivity of free space, Planck's ... 03:28: ... charge of the electron is in Couloumbs,  the speed of light in meters per second, vacuum ... 04:05: ... example, the repulsive energy between two electrons is 137 smaller than a photon with wavelength equal to the  distance ... 04:17: And the orbital speed of an electron in the ground state of the Bohr model of the hydrogen atom is 137 slower than the speed of light. 04:26: And the energy of that ground state electron  is smaller than the rest mass energy of the electron by a factor of 137 squared. 06:02: ... square of alpha is the base probability that an electron will emit or absorb a photon, or in the case of two electrons ... 06:29: The more chance of interaction between the  electron and electromagnetic fields, the more of an EM disturbance each electron will make. 08:03: ... constant sets the size of atoms - a larger  value means electrons would be closer to nuclei, making them more tightly bound and less  ... 08:16: A smaller value would mean electrons were less tightly bound, making atoms and molecules less stable. 10:38: ... two things with the same units, like the ratio of the  mass of the electron and  proton, or the coefficient of friction of an inclined ... 13:07: Or perhaps it hints at a deeper connection  between the properties of  the elementary particles, like the mass and charge of the electron. 10:38: ... two things with the same units, like the ratio of the  mass of the electron and  proton, or the coefficient of friction of an inclined ... 02:55: ... multiple of one particular  number: the square of the charge of the electron, divided by four times pi, the permittivity of free space, Planck's constant and ... 04:26: And the energy of that ground state electron  is smaller than the rest mass energy of the electron by a factor of 137 squared. 06:02: ... - it’s the base probability at each vertex, each interaction between electron  and virtual photon, adjusted by all these other parameters I ... 01:34: As with much of quantum mechanics, it started  with us watching the light produced as electrons flicked between energy levels in atoms. 02:36: ... still-new relativity, as well as the fact that the energy levels of electrons with opposite spins are separated slightly by their interaction with ... 04:05: ... example, the repulsive energy between two electrons is 137 smaller than a photon with wavelength equal to the  distance ... 06:02: ... that an electron will emit or absorb a photon, or in the case of two electrons interacting by,  say Feynman diagrams - it’s the base probability ... 08:03: ... constant sets the size of atoms - a larger  value means electrons would be closer to nuclei, making them more tightly bound and less  ... 08:16: A smaller value would mean electrons were less tightly bound, making atoms and molecules less stable. 01:34: As with much of quantum mechanics, it started  with us watching the light produced as electrons flicked between energy levels in atoms. 06:02: ... that an electron will emit or absorb a photon, or in the case of two electrons interacting by,  say Feynman diagrams - it’s the base probability at each ...
	2022-09-21: Science of the James Webb Telescope Explained! 13:19: This constant exchange process keeps the nucleons bound together, analogously to how the atoms in molecules are bound by the exchange of electrons.
	2022-09-14: Could the Higgs Boson Lead Us to Dark Matter? 00:54: We see and we feel the atoms - the electrons and the quarks - via the protons and neutrons. 01:18: ... but you don’t notice because they extremely rarely interact with the electrons and quarks that make up the atoms that make up ... 02:44: The standard model particle could be a quark, an electron, or anything that makes up normal matter. 06:01: ... that excludes the electrically charged leptons: electrons, muons and tau particles; it excludes the quarks and whatever is made of ... 10:50: But every neutrino has to be created with an electron, muon or tau particle partner. 06:55: ... Z was thoroughly studied at the Large Electron-Position Collider, but no evidence was found supporting interactions with dark ... 00:54: We see and we feel the atoms - the electrons and the quarks - via the protons and neutrons. 01:18: ... but you don’t notice because they extremely rarely interact with the electrons and quarks that make up the atoms that make up ... 06:01: ... that excludes the electrically charged leptons: electrons, muons and tau particles; it excludes the quarks and whatever is made of ...
	2022-08-24: What Makes The Strong Force Strong? 00:22: As you know, atoms consist of a nucleus of protons and neutrons surrounded by electrons. 00:28: ... electrons are held in their orbitals by the electromagnetic force - opposite ... 00:46: Their multiple electrons repel each other, but fortunately are spread out enough to not disturb each other too much. 03:24: That includes electrons, quarks, and many of the particles that are composed of quarks. 03:33: One consequence of this is that no two electrons can occupy the same energy level in an atom. 03:38: Well, slight correction: electron orbitals can contain two electrons, but that’s because those electrons can have a different spin state. 06:20: So an electron bound to an atomic nucleus will feel less force from the nucleus at larger orbitals. 06:25: The further the electron gets from the nucleus, the more easily it can escape. 08:49: Let's say we have a proton and an electron, their electric charges attract and they form a neutral hydrogen atom. 09:05: You would have to get really close to an atom to feel the positive electric field of the nucleus, or the negative electric field of the electrons. 06:20: So an electron bound to an atomic nucleus will feel less force from the nucleus at larger orbitals. 03:38: Well, slight correction: electron orbitals can contain two electrons, but that’s because those electrons can have a different spin state. 00:22: As you know, atoms consist of a nucleus of protons and neutrons surrounded by electrons. 00:28: ... electrons are held in their orbitals by the electromagnetic force - opposite ... 00:46: Their multiple electrons repel each other, but fortunately are spread out enough to not disturb each other too much. 03:24: That includes electrons, quarks, and many of the particles that are composed of quarks. 03:33: One consequence of this is that no two electrons can occupy the same energy level in an atom. 03:38: Well, slight correction: electron orbitals can contain two electrons, but that’s because those electrons can have a different spin state. 09:05: You would have to get really close to an atom to feel the positive electric field of the nucleus, or the negative electric field of the electrons. 03:24: That includes electrons, quarks, and many of the particles that are composed of quarks. 00:46: Their multiple electrons repel each other, but fortunately are spread out enough to not disturb each other too much.
	2022-08-03: What Happens Inside a Proton? 01:15: ... is good for simulating the electrons in an atom. But the behavior of electrons is   ... 01:31: ... quantum   electrodynamics describes the interactions of electrons and any other charged particle   via photons. We’re going to ... 02:06: ... are an example. To test QED we can chuck a photon at an electron and see what happens.   But to test QCD, we can’t just poke a ... 03:12: ... Say we want to predict what happens when two electrons are shot towards each other.   We can actually calculate the ... 04:17: ... Feynman diagram represents the probability of a pair of   electrons interacting with the electromagnetic  field - emitting and ... 16:44: ... to the entanglement experiment, done with a pair of   electrons with undefined but opposite spins to each other. In the case of the ... 18:44: ... we could determine   the spin direction of an electron without  measuring it, only confirming it afterwards.   ... 16:44: ... in a box, or if it happens when you open the box. But   electron spin also has a directional axis - e.g. up-down, left-right, ... 18:44: ... we could determine   the spin direction of an electron without  measuring it, only confirming it afterwards.   Actually, ... 05:14: ... the fine structure constant. It’s the coupling strength between the electron   and electromagnetic field. The smallness  of the fine structure ... 03:12: ... or more, or one of those photons   could spontaneously form an electron-positron pair before becoming a photon again, and so on.   Each family of ... 01:15: ... is good for simulating the electrons in an atom. But the behavior of electrons is   ... 01:31: ... quantum   electrodynamics describes the interactions of electrons and any other charged particle   via photons. We’re going to ... 03:12: ... Say we want to predict what happens when two electrons are shot towards each other.   We can actually calculate the ... 04:17: ... Feynman diagram represents the probability of a pair of   electrons interacting with the electromagnetic  field - emitting and ... 16:44: ... to the entanglement experiment, done with a pair of   electrons with undefined but opposite spins to each other. In the case of the ... 18:44: ... in the glove in a box analogy, if you can measure the spin of an electron’s entangled   partner then you know what its spin is. ... 01:15: ... is good for simulating the electrons in an atom. But the behavior of electrons is   comparatively baby ... 04:17: ... Feynman diagram represents the probability of a pair of   electrons interacting with the electromagnetic  field - emitting and absorbing a ... 01:15: ... good for simulating the electrons in an atom. But the behavior of electrons is   comparatively baby stuff compared to the atomic nucleus. Every ... 18:44: ... isn't a passive act - you will   have actually forced the electron’s spin  to be in the direction of the ...
	2022-07-27: How Many States Of Matter Are There? 01:09: Electrons are knocked free from atoms, breaking all molecular bonds in the process and creating a Plasma. 05:05: ... plasma still consists of composite particles: the electrons are elementary, but the atomic nuclei are little bundles of nucleons - ... 01:09: Electrons are knocked free from atoms, breaking all molecular bonds in the process and creating a Plasma. 05:05: ... plasma still consists of composite particles: the electrons are elementary, but the atomic nuclei are little bundles of nucleons - ...
	2022-07-20: What If We Live in a Superdeterministic Universe? 00:26: Photons passing through two slits at once, electrons being spin up and down, cats being both alive and dead. 02:50: For example an electron can be spinning in two different directions simultaneously. 03:06: Let’s say we have a pair of electrons; each is in a superposition of spin states, say, with spin axis simultaneously up and down. 03:17: ... the electrons could also be entangled with each other so that their spins are ... 03:27: Measurement of one electron would influence the other in a very real way - something Einstein referred to as spooky action at a distance. 03:46: We prepare a pair of entangled electrons. 03:54: We give one electron to Alice and one to Bob who then go back to their separate labs to measure the spin. 04:37: A horizontal measurement will yield a 50-50 chance of being left or right for his down-pointing electron. 05:34: ... thought that each electron had to carry all the information about its own physical state, in a way ... 05:44: We can imagine the same scenario in the case where the electrons do know their own spin all along. 06:36: ... statement - the Bell inequality that is true in the case that the electron spins are set from the beginning and contained within the electron - but ... 08:28: Alice and Bob start out together, acquire their entangled electrons, and then move sideways in space and up in time. 08:47: But quantum mechanics says that when Alice measures her electron, Bob’s electron is instantly affected. 08:56: Now let’s look at the case where the electrons start out with defined spins. 09:01: ... that Alice and Bob observe opposite spins because we can see that both electron’s spins were determined by a single event in both of their past light ... 09:36: Locality and realism would have been saved if it turned out that the states of the electrons were fixed when their past lightcones overlapped. 12:46: Now, this experiment used the polarization direction of photons rather than the spin direction of electrons, but it’s the same deal. 17:13: If the aliens simply describe the hydrogen atom and we saw that its electron had positive charge, we’d be set. 06:36: ... the electron spins are set from the beginning and contained within the electron - but false if standard quantum mechanics is right and spin is undefined ... 08:47: But quantum mechanics says that when Alice measures her electron, Bob’s electron is instantly affected. 06:36: ... statement - the Bell inequality that is true in the case that the electron spins are set from the beginning and contained within the electron - but false ... 00:26: Photons passing through two slits at once, electrons being spin up and down, cats being both alive and dead. 03:06: Let’s say we have a pair of electrons; each is in a superposition of spin states, say, with spin axis simultaneously up and down. 03:17: ... the electrons could also be entangled with each other so that their spins are ... 03:46: We prepare a pair of entangled electrons. 05:44: We can imagine the same scenario in the case where the electrons do know their own spin all along. 08:28: Alice and Bob start out together, acquire their entangled electrons, and then move sideways in space and up in time. 08:56: Now let’s look at the case where the electrons start out with defined spins. 09:01: ... that Alice and Bob observe opposite spins because we can see that both electron’s spins were determined by a single event in both of their past light ... 09:36: Locality and realism would have been saved if it turned out that the states of the electrons were fixed when their past lightcones overlapped. 12:46: Now, this experiment used the polarization direction of photons rather than the spin direction of electrons, but it’s the same deal. 09:01: ... that Alice and Bob observe opposite spins because we can see that both electron’s spins were determined by a single event in both of their past light ... 08:56: Now let’s look at the case where the electrons start out with defined spins.
	2022-06-30: Could We Decode Alien Physics? 00:00: ... the particle carried by the   alien circuitry looks like the electron. We  decide this through a process of elimination.  The aliens ... 01:25: ... no. Unbeknownst to us, these aliens use positronic circuitry, not electronic. It’s just   that they define electric charge in the ... 02:25: ... as positive.  We now know that it’s the other way  around. Electrons from the rod are actually   rubbed off onto the cloth, so ... 07:38: ... quantum spin for a minute to  define this rule. Say you have an electron moving   through a magnetic field. That field is going ... 11:52: ... distinguish. We might build a time-forward,  right-handed, electronic device instead of   the alien’s intended time-reversed, ... 02:25: ... and a half later before we actually discovered that the electron existed. That discovery finally allowed us to figure out which way this ... 07:38: ... quantum spin for a minute to  define this rule. Say you have an electron moving   through a magnetic field. That field is going to apply a force in ... 00:00: ... the particle carried by the   alien circuitry looks like the electron. We  decide this through a process of elimination.  The aliens describe ... 01:25: ... no. Unbeknownst to us, these aliens use positronic circuitry, not electronic. It’s just   that they define electric charge in the ... 11:52: ... distinguish. We might build a time-forward,  right-handed, electronic device instead of   the alien’s intended time-reversed, ... 01:25: ... of physics alone.  So we build the device with its  incorrect electronic circuitry.   The President exerts some pressure  to switch it on already ... 11:52: ... distinguish. We might build a time-forward,  right-handed, electronic device instead of   the alien’s intended time-reversed, ... 00:00: ... noticing that the alien technology seems to use good ol’ fashioned electronics,   even if it is insanely complex. We know  this because the particle ... 07:38: ... That field is going to apply a force in some direction to that electron.   To find that direction you just point the index finger of your ... 01:25: ... that they define electric charge in the opposite way - electrons positive, positrons negative.   But how could we make such a ... 02:25: ... as positive.  We now know that it’s the other way  around. Electrons from the rod are actually   rubbed off onto the cloth, so ... 01:25: ... that they define electric charge in the opposite way - electrons positive, positrons negative.   But how could we make such a blunder? ... 05:33: ... its charge sign convention,   distinguish positrons from electrons,  and hopefully not explode the ...
	2022-06-22: Is Interstellar Travel Impossible? 11:16: Such atoms will be stripped of their electrons to become high-energy protons, in other words, they become radiation. 16:16: Yash Chaurasia asks whether asking an electron "are you a particle?" automatically answers "are you a wave?”. 11:16: Such atoms will be stripped of their electrons to become high-energy protons, in other words, they become radiation.
	2022-06-01: What If Physics IS NOT Describing Reality? 00:25: ... - no one has to solve the Schrodinger  equation in order for an electron to be able to do   its thing. Our laws of nature are just ... 05:38: ... say we prepare an electron’s spin  to all point up relative to our apparatus.   The ... 05:53: ... what if we asked the  electron spin a different question “are you pointing   left or right?” ... 07:23: ... entanglement also fits this picture.  When we prepared our electrons to be spin-up,   that spin was relative to a chosen direction ... 05:53: ... what if we asked the  electron spin a different question “are you pointing   left or right?” We ... 07:23: ... spin, but rather spread between   two electrons. Two electron spins contain two  bits, but those bits are distributed ... 05:38: ... say we prepare an electron’s spin  to all point up relative to our apparatus.   The ... 07:23: ... entanglement also fits this picture.  When we prepared our electrons to be spin-up,   that spin was relative to a chosen direction ... 05:38: ... say we prepare an electron’s spin  to all point up relative to our apparatus.   The spin contains ...
	2022-05-04: Space DOES NOT Expand Everywhere 15:31: ... ideas. The other famous one is the one-electron universe, in which all electrons are actually the same electron bouncing back and forward in time. Wacky ... 16:38: ... put me in mind of the way the electron in the admittedly outdated Bohr model of the atom in a sense “creates ... 15:31: ... the one-electron universe, in which all electrons are actually the same electron bouncing back and forward in time. Wacky as they are, they tend to have legs ... 16:38: ... the atom in a sense “creates itself” by constructive interference - only electrons whose wavefunction peaks and valleys line up on each orbit can exist. ...
	2022-03-23: Where Is The Center of The Universe? 16:48: That means there was not much of a difference between Up and Down quarks or between electrons and their neutrinos. 16:55: Just like it makes no sense to distinguish electrons with up or down spin as different particles. 16:48: That means there was not much of a difference between Up and Down quarks or between electrons and their neutrinos. 16:55: Just like it makes no sense to distinguish electrons with up or down spin as different particles.
	2022-03-16: What If Charge is NOT Fundamental? 02:23: For example electrons have this thing called spin - a quantum analogy to angular momentum. 02:43: And spin is conserved - flip an electron’s spin and the difference has to be transferred by a photon. 04:54: Similar to how the electron and positron are only created in pairs in order to conserve electric charge. 10:05: For example, the electron has both a right- and left-handed component. 10:27: We can play the same trick with the electron and neutrino. 11:30: Particles like the electron, the neutrino, and even the quark. 02:23: For example electrons have this thing called spin - a quantum analogy to angular momentum. 02:43: And spin is conserved - flip an electron’s spin and the difference has to be transferred by a photon. 02:30: ... can take on discrete values; in the electrons  it can be +1/2 or -1/2, loosely corresponding to the spin axis being ...
	2022-03-08: Is the Proxima System Our Best Hope For Another Earth? 03:22: ... was in its emission lines - sharp spikes in its spectrum resulting from electron transitions in the atoms and molecules of the star’s ...
	2022-02-10: The Nature of Space and Time AMA 00:03: ... energy levels of atoms when you look at the light emitted due to electron tractions in atoms very far away backwards in time then um ...
	2022-01-27: How Does Gravity Escape A Black Hole? 07:05: Let’s say two electrons approach each other. 07:21: ... the electromagnetic field in the broader region occupied by both of the electrons, and their summed effect leads to a repulsive force between the ... 14:21: We said that in density function theory you start with a make-believe system of non-interacting electrons. 14:27: ... guess, and that the remaining part you have to approximate is the electron ... 07:05: Let’s say two electrons approach each other. 07:21: ... the electromagnetic field in the broader region occupied by both of the electrons, and their summed effect leads to a repulsive force between the ... 14:21: We said that in density function theory you start with a make-believe system of non-interacting electrons. 07:05: Let’s say two electrons approach each other.
	2022-01-12: How To Simulate The Universe With DFT 00:44: ... example, let’s say you want to know the intricate behavior of an electron, whether it’s bouncing around inside a box, or part of a hydrogen atom, ... 00:54: ... the blackboard and solve it to learn the probability distribution of the electron locations, or the energy levels of the system, or ... 01:06: That’s neat if you’re really, really interested in only that single electron. 01:28: In fact you need more particles than exist in the solar system to store the wavefunction of the electrons in a single iron atom. 02:10: ... an electron in a box or in a hydrogen atom, the different possible values of E that ... 02:19: ... gives the the probability distribution for where you’ll find the electron if you try to measure ... 03:25: OK, now let’s say we want to do the 26 electrons in an iron atom instead of the 1 electron in hydrogen. 03:38: Those electrons are all interacting with each other, and that increases the information content just a tad. 03:44: Each new electron doesn’t just add a new set of values to the same 3-D array. 03:50: Every new electron adds 3 new entire dimensions. 03:53: So 26 electrons means 78 dimensions, which for our 10-point grid is 10^78 numbers. 05:00: The x, y, and z in the Psi of the first electron isn’t the same x, y, and z in the Psi in the second. 05:07: For every coordinate point for electron one, we need to consider separately every coordinate point for electron two. 05:15: ... for a given pair of coordinate points for electrons one and two, we need to consider every possible point for electron 3 … ... 09:01: ... density functional theory, and here’s resonant excitation in the many electrons of a ... 09:32: In the case of DFT, what you do is just pretend the electrons aren’t interacting with each other and solve for that case. 09:59: ... first theorem basically states that if you have a system of electrons in their ground state, no matter how complicated, the properties of that ... 10:11: ... of the information held in the total wavefunction of all of those electrons. ... 10:21: It’s a 3-D entity - just a map of how much “electron-ness” exists through space. 10:42: ... and we do this for the totally unrealistic case of non-interacting electrons. ... 10:54: Because they aren’t interacting, the equations of motion for these electrons are separable, just like in Newtonian mechanics. 05:15: ... we need to consider every possible point for electron 3 … and so on to electron 26. ... 03:50: Every new electron adds 3 new entire dimensions. 03:44: Each new electron doesn’t just add a new set of values to the same 3-D array. 05:00: The x, y, and z in the Psi of the first electron isn’t the same x, y, and z in the Psi in the second. 00:54: ... the blackboard and solve it to learn the probability distribution of the electron locations, or the energy levels of the system, or ... 10:21: It’s a 3-D entity - just a map of how much “electron-ness” exists through space. 01:28: In fact you need more particles than exist in the solar system to store the wavefunction of the electrons in a single iron atom. 03:25: OK, now let’s say we want to do the 26 electrons in an iron atom instead of the 1 electron in hydrogen. 03:38: Those electrons are all interacting with each other, and that increases the information content just a tad. 03:53: So 26 electrons means 78 dimensions, which for our 10-point grid is 10^78 numbers. 05:15: ... for a given pair of coordinate points for electrons one and two, we need to consider every possible point for electron 3 … ... 09:01: ... density functional theory, and here’s resonant excitation in the many electrons of a ... 09:32: In the case of DFT, what you do is just pretend the electrons aren’t interacting with each other and solve for that case. 09:59: ... first theorem basically states that if you have a system of electrons in their ground state, no matter how complicated, the properties of that ... 10:11: ... of the information held in the total wavefunction of all of those electrons. ... 10:42: ... and we do this for the totally unrealistic case of non-interacting electrons. ... 10:54: Because they aren’t interacting, the equations of motion for these electrons are separable, just like in Newtonian mechanics.
	2021-12-10: 2021 End of Year AMA! 00:02: ... uh i apologize for my pronunciation um and the question is when an electron emits a photon and another particle let's say a proton absorbs it ...
	2021-11-02: Is ACTION The Most Fundamental Property in Physics? 12:59: ... eponymous equation was derived to describe the quantum evolution of the electron. ...
	2021-10-20: Will Constructor Theory REWRITE Physics? 10:51: ... mechanics by stripping away all but the bare facts about the nature of electron  energy levels - including  abandoning any pre-existing dynamical ...
	2021-10-13: New Results in Quantum Tunneling vs. The Speed of Light 04:03: ... and it’s even a critical part of the working of transistors and other electronic ...
	2021-10-05: Why Magnetic Monopoles SHOULD Exist 00:26: Take a metal bar and force all the electrons to one end. 01:43: In a ferromagnet, the field is the sum of the countless tiny aligned dipole fields of electrons in the magnet’s atoms. 01:51: ... to make a dipole magnetic field is the electromagnet - where were push electrons around in a circle In both cases - electron spin or or a circular ... 06:57: Imagine a charged particle - say an electron - passing by a Dirac string. 07:02: To plot that trajectory you add up all possible paths of the electron, including paths to the left and to the right at the string. 07:09: ... different phase shifts depending on which side of the string the electron passes - and that would actually have a noticeable effect on the path of ... 08:25: And of course we know that electric charge really is quantized - it can only be integer multiples of the charge of the electron. 08:31: Or maybe of quarks - a third the electron charge. 11:36: GUTs predict that monopoles should be produced in enormous numbers in the very early universe - as abundantly as protons and electrons. 15:08: We represented very distinctly separated electron energy levels in our explanation of how fermion’s can’t occupy identical quantum states. 15:16: ... notes that energy levels in atoms can actually hold 2 electrons, not one, because it’s possible to have two electrons at the same energy ... 16:57: In the case of the collapsing star, densities and energies become high enough for electrons to be captured by protons, converting them to neutrons. 17:05: So the loss of electrons reduces the degeneracy pressure, allowing gravitational collapse to continue. 06:57: Imagine a charged particle - say an electron - passing by a Dirac string. 08:31: Or maybe of quarks - a third the electron charge. 15:08: We represented very distinctly separated electron energy levels in our explanation of how fermion’s can’t occupy identical quantum states. 07:02: To plot that trajectory you add up all possible paths of the electron, including paths to the left and to the right at the string. 07:09: ... different phase shifts depending on which side of the string the electron passes - and that would actually have a noticeable effect on the path of the ... 01:51: ... - where were push electrons around in a circle In both cases - electron spin or or a circular electric current there’s a sense of electric charge in ... 00:26: Take a metal bar and force all the electrons to one end. 01:43: In a ferromagnet, the field is the sum of the countless tiny aligned dipole fields of electrons in the magnet’s atoms. 01:51: ... to make a dipole magnetic field is the electromagnet - where were push electrons around in a circle In both cases - electron spin or or a circular ... 11:36: GUTs predict that monopoles should be produced in enormous numbers in the very early universe - as abundantly as protons and electrons. 15:16: ... notes that energy levels in atoms can actually hold 2 electrons, not one, because it’s possible to have two electrons at the same energy ... 16:57: In the case of the collapsing star, densities and energies become high enough for electrons to be captured by protons, converting them to neutrons. 17:05: So the loss of electrons reduces the degeneracy pressure, allowing gravitational collapse to continue.
	2021-09-21: How Electron Spin Makes Matter Possible 00:00: ... right now using one simple fact, and one object. The fact is that all electrons are the same as each other, and the object is a structurally critical ... 00:26: ... that quantum spin is very weird. We talked all about that recently - how electrons have spin but aren’t really rotating. And about how you need to turn an ... 01:13: ... and include all the particles that we think of as matter - from electrons to quarks to the neutrinos. The other spin behavior is to have integer ... 01:44: ... - no two fermions can share the same quantum state, which is why electrons can’t occupy the same energy states in atoms. Without this, electrons in ... 02:18: ... symmetry, and 2) indistinguishability - which is just the fact that all electrons, for example, are exactly the same - there is no observable change when ... 03:46: ... the belt is flat. Let’s think of the belt buckle as a particle - say an electron - and the belt is its connection to whatever - the universe, or to maybe ... 04:43: ... can think both ends of the belt as spinor particles like electrons, and in that case we can do another experiment. What happens if the ends ... 05:27: We’ll come back to how electrons can have this property and yet still be indistinguishable. 05:59: ... How do we connect all of this to actual electrons? Well electrons don’t really rotate in the classical sense. They’re ... 06:49: ... spinor wavefunction of the electron can “wave” through space, but it includes another wavy part. It has its ... 07:22: ... so summarizing again: Electrons are spinors and so require a 720 degree rotation to be returned to their ... 08:00: ... addition and subtraction here. Let’s think about the quantum state of an electron. We’ll call it Psi. Psi gives the distribution of probabilities of some ... 08:37: ... let’s put our electron in an atom - in the ground state. And add a second electron to the first ... 09:08: ... Electrons are fermions, which means that if we swap their locations the ... 10:12: ... is equal to the square of Psi(B,A) But although we can’t distinguish electron A from electron B through observation of these particles, it turns out ... 10:32: ... looks like in terms of the individual wavefunctions of our two electrons. We’ll call the individual electron wavefunctions g and f - if you like ... 12:04: ... is just the negative of the original. So Psi(B,A) = -Psi(A,B) - swapping electrons flips the sign - so we’ve successfully discovered the wavefunction for a ... 12:20: ... VERY close now. I’m now going to show you that we can’t shove both electrons into the same state. Let’s say we want both electrons to be in the ... 12:37: ... sign - which causes those two components to cancel out. Essentially, two electrons shoved into the same state end up perfectly out of phase and so ... 13:25: ... in the Dirac equation - which is the quantum equation of motion for electrons and other spin-½ ... 14:26: ... it - matter has structure and you don’t fall through your chair because electrons are indistinguishable and they obey a simple, if odd, rotational ... 03:46: ... the belt is flat. Let’s think of the belt buckle as a particle - say an electron - and the belt is its connection to whatever - the universe, or to maybe ... 10:32: ... individual wavefunctions of our two electrons. We’ll call the individual electron wavefunctions g and f - if you like for the ground and first excited state of the ... 00:00: ... right now using one simple fact, and one object. The fact is that all electrons are the same as each other, and the object is a structurally critical ... 00:26: ... that quantum spin is very weird. We talked all about that recently - how electrons have spin but aren’t really rotating. And about how you need to turn an ... 01:13: ... and include all the particles that we think of as matter - from electrons to quarks to the neutrinos. The other spin behavior is to have integer ... 01:44: ... - no two fermions can share the same quantum state, which is why electrons can’t occupy the same energy states in atoms. Without this, electrons in ... 02:18: ... symmetry, and 2) indistinguishability - which is just the fact that all electrons, for example, are exactly the same - there is no observable change when ... 04:43: ... can think both ends of the belt as spinor particles like electrons, and in that case we can do another experiment. What happens if the ends ... 05:27: We’ll come back to how electrons can have this property and yet still be indistinguishable. 05:59: ... How do we connect all of this to actual electrons? Well electrons don’t really rotate in the classical sense. They’re ... 07:22: ... so summarizing again: Electrons are spinors and so require a 720 degree rotation to be returned to their ... 08:37: ... a second electron to the first excited state. We can think of these two electrons as having a shared wavefunction - a two-particle wavefunction we’ll call ... 09:08: ... Electrons are fermions, which means that if we swap their locations the ... 10:32: ... looks like in terms of the individual wavefunctions of our two electrons. We’ll call the individual electron wavefunctions g and f - if you like ... 12:04: ... is just the negative of the original. So Psi(B,A) = -Psi(A,B) - swapping electrons flips the sign - so we’ve successfully discovered the wavefunction for a ... 12:20: ... VERY close now. I’m now going to show you that we can’t shove both electrons into the same state. Let’s say we want both electrons to be in the ... 12:37: ... sign - which causes those two components to cancel out. Essentially, two electrons shoved into the same state end up perfectly out of phase and so ... 13:25: ... in the Dirac equation - which is the quantum equation of motion for electrons and other spin-½ ... 14:26: ... it - matter has structure and you don’t fall through your chair because electrons are indistinguishable and they obey a simple, if odd, rotational ... 12:37: ... out of phase and so destructively interfere. But you can’t just vanish electrons - so the transition of an electron into an occupied quantum state is ... 02:18: ... are exactly the same - there is no observable change when you swap two electrons. Combining spin behavior and indistinguishability gives us something called the ... 05:59: ... How do we connect all of this to actual electrons? Well electrons don’t really rotate in the classical sense. They’re quantum objects described ... 12:04: ... is just the negative of the original. So Psi(B,A) = -Psi(A,B) - swapping electrons flips the sign - so we’ve successfully discovered the wavefunction for a pair ... 12:37: ... sign - which causes those two components to cancel out. Essentially, two electrons shoved into the same state end up perfectly out of phase and so destructively ...
	2021-09-15: Neutron Stars: The Most Extreme Objects in the Universe 02:00: ... magnetized space around the earth or sun.   It’s filled with electrons and  positrons. These matter-antimatter   pairs are ... 03:07: ... a plasma,   in which atoms have been stripped of  their electrons, or ionized,   due to the extreme heat - around a million  ... 04:04: ... mass star like our Sun. The plasma is crushed so tight that electrons are on the verge of   overlapping. But as we saw in previous ... 04:39: ... we normally think of crystals as lattices of atoms connected by electron bonds.   But the stuff below our feet is still ... 05:48: ... as we go down. Suffusing the crystal   lattice is a gas of electrons - a so-called  degenerate fermi gas that holds up this part ... 07:43: ... between the nuclei fills with a   neutron gas. Meanwhile the electron gas gets thinner due to the electron capture process.   ... 04:39: ... we normally think of crystals as lattices of atoms connected by electron bonds.   But the stuff below our feet is still completely ionized - stripped ... 07:43: ... neutron gas. Meanwhile the electron gas gets thinner due to the electron capture process.   In fact the neutron gas starts to take over ... 02:00: ... That field then becomes a particle accelerator, with electron currents flowing one way and   positron currents flowing the other way- ... 07:43: ... between the nuclei fills with a   neutron gas. Meanwhile the electron gas gets thinner due to the electron capture process.   In ... 06:38: ... are only stabilized by the incredible   pressures and extreme electron  energies in the neutron ... 04:04: ... quantum state. The matter has  become what we call degenerate, and electron   degeneracy pressure stops further collapse and ultimately holds the ... 02:00: ... magnetized space around the earth or sun.   It’s filled with electrons and  positrons. These matter-antimatter   pairs are ... 03:07: ... a plasma,   in which atoms have been stripped of  their electrons, or ionized,   due to the extreme heat - around a million  ... 04:04: ... mass star like our Sun. The plasma is crushed so tight that electrons are on the verge of   overlapping. But as we saw in previous ... 04:39: ... stuff below our feet is still completely ionized - stripped of its electrons. In fact it’s   a frozen plasma, in which its nuclei are ... 05:48: ... as we go down. Suffusing the crystal   lattice is a gas of electrons - a so-called  degenerate fermi gas that holds up this part ... 07:43: ... In fact the neutron gas starts to take over the role of the electrons. Neutrons are also fermions,   and so two of them can’t occupy ... 05:48: ... as we go down. Suffusing the crystal   lattice is a gas of electrons - a so-called  degenerate fermi gas that holds up this part ... 02:00: ... magnetized space around the earth or sun.   It’s filled with electrons and  positrons. These matter-antimatter   pairs are created out of ... 07:43: ... In fact the neutron gas starts to take over the role of the electrons. Neutrons are also fermions,   and so two of them can’t occupy the same ... 05:48: ... are high enough to drive some very exotic nuclear reactions. Electrons start to   be driven into the iron nuclei in a process ...
	2021-09-07: First Detection of Light from Behind a Black Hole 04:57: This gas starts to glow in a different way - not from heat, but from the motion of electrons between their atomic energy levels. 05:15: In a normal spectrum we see the light from these electron transitions as sharp spikes at specific wavelengths - what we call emission lines. 09:51: The intense radiation in this region strips almost all atoms of their electrons. 09:57: That leads to a haze of high-energy electrons surrounding the black hole. 10:01: As light from the accretion disk passes through this haze it gains energy from the electrons, boosting it all the way up to X-ray energies. 10:12: ... hole only the heaviest elements like iron can hold on to any of their electrons. ... 05:15: In a normal spectrum we see the light from these electron transitions as sharp spikes at specific wavelengths - what we call emission lines. 04:57: This gas starts to glow in a different way - not from heat, but from the motion of electrons between their atomic energy levels. 09:51: The intense radiation in this region strips almost all atoms of their electrons. 09:57: That leads to a haze of high-energy electrons surrounding the black hole. 10:01: As light from the accretion disk passes through this haze it gains energy from the electrons, boosting it all the way up to X-ray energies. 10:12: ... hole only the heaviest elements like iron can hold on to any of their electrons. ... 10:01: As light from the accretion disk passes through this haze it gains energy from the electrons, boosting it all the way up to X-ray energies. 09:57: That leads to a haze of high-energy electrons surrounding the black hole.
	2021-08-10: How to Communicate Across the Quantum Multiverse 09:57: ... lays out the steps very clearly: you send a spin half particle like an electron through a Stern-Gerlach device and then you measure the direction of the ... 11:05: First, you, but not other you, need to inject some information into the electron’s wavefunction. 11:11: ... do that by making a choice: either you leave the electron with spin-down, or you rotate it to spin-up. After that, both you’s send ... 12:00: ... to send more than a single bit. Unfortunately you can’t just use more electrons, because each electron further splits the worlds - you’ll just be sending ... 16:58: ... field in many ways, including by watching the radio light emitted by electrons spiraling in that magnetic field - what we call synchrotron radiation. ... 11:11: ... chose to rotate your electron from down to up, other you will find their electron rotated from up to down. If you did nothing, other you will also find no ... 11:05: First, you, but not other you, need to inject some information into the electron’s wavefunction. 11:11: ... - each world - through the entire electron wavefunction. Finally, the electrons go back through the Stern-Gerlach device and other you measures the spin ... 12:00: ... to send more than a single bit. Unfortunately you can’t just use more electrons, because each electron further splits the worlds - you’ll just be sending ... 16:58: ... field in many ways, including by watching the radio light emitted by electrons spiraling in that magnetic field - what we call synchrotron radiation. ... 11:05: First, you, but not other you, need to inject some information into the electron’s wavefunction.
	2021-08-03: How An Extreme New Star Could Change All Cosmology 03:19: ... a full forensic workup. For example, it gives us spectral lines. When electrons in an atom move between orbitals, they emit or absorb light with very ... 06:21: ... up from absolute collapse is the fact that if it got any smaller, its electrons would start to overlap - they’d have to occupy the same energy states. ... 06:51: ... atoms, electrons are held in place by the coulomb force - electrostatic attraction to the ... 12:50: ... 1000 times denser still. That means it can support incredibly energetic electrons in its core - electrons so energetic they are in danger of slamming into ... 13:13: ... sink, or sediment, to the core. These nuclei are more susceptible to electron ... 13:30: ... build up enough of that stuff in the center and the electron capture chain reaction may begin - giving us another path to supernova, ... 14:52: ... white dwarf blessings: may your magnetic fields stay untangled, your electrons be ever degenerate, and may your mass remain always ... 15:19: ... is something else - it’s the Pauli Exclusion principle, which says that electrons in atoms can’t be shoved into each other to occupy the same energy ... 12:50: ... If that starts to happen then you get a chain reaction of so-called electron capture which is how you turn a white dwarf into a neutron ... 13:13: ... sink, or sediment, to the core. These nuclei are more susceptible to electron capture. ... 13:30: ... build up enough of that stuff in the center and the electron capture chain reaction may begin - giving us another path to supernova, and a ... 03:19: ... a full forensic workup. For example, it gives us spectral lines. When electrons in an atom move between orbitals, they emit or absorb light with very ... 06:21: ... up from absolute collapse is the fact that if it got any smaller, its electrons would start to overlap - they’d have to occupy the same energy states. ... 06:51: ... atoms, electrons are held in place by the coulomb force - electrostatic attraction to the ... 12:50: ... 1000 times denser still. That means it can support incredibly energetic electrons in its core - electrons so energetic they are in danger of slamming into ... 14:52: ... white dwarf blessings: may your magnetic fields stay untangled, your electrons be ever degenerate, and may your mass remain always ... 15:19: ... is something else - it’s the Pauli Exclusion principle, which says that electrons in atoms can’t be shoved into each other to occupy the same energy ...
	2021-07-21: How Magnetism Shapes The Universe 02:43: ... - for example the electric current in an electromagnet, or the aligned electron spins in a ferromagnet, then that current will want to loop around the ... 07:09: These fields drive the motion of lone electrons throughout the interstellar medium. 07:15: When radio waves interact with those electrons, their polarizations are also affected. 07:21: The presence of these electrons tends to slow light down - just as light is slowed down in air or glass - but to a much smaller degree. 07:55: The electrons in their magnetic fields tend to slow one circular polarization direction more than the other. 11:08: Electrons and atomic nuclei can be accelerated in this magnetic field to high energies - into what we call cosmic rays. 12:23: ... out into the cosmos, and we see them through the radio light emitted by electrons that spiral slowly in these vast ... 14:30: In ferromagnets, the “moving” charges are the electron spins. 02:43: ... - for example the electric current in an electromagnet, or the aligned electron spins in a ferromagnet, then that current will want to loop around the ... 14:30: In ferromagnets, the “moving” charges are the electron spins. 07:09: These fields drive the motion of lone electrons throughout the interstellar medium. 07:15: When radio waves interact with those electrons, their polarizations are also affected. 07:21: The presence of these electrons tends to slow light down - just as light is slowed down in air or glass - but to a much smaller degree. 07:55: The electrons in their magnetic fields tend to slow one circular polarization direction more than the other. 11:08: Electrons and atomic nuclei can be accelerated in this magnetic field to high energies - into what we call cosmic rays. 12:23: ... out into the cosmos, and we see them through the radio light emitted by electrons that spiral slowly in these vast ...
	2021-07-13: Where Are The Worlds In Many Worlds? 04:54: ... is in the double-slit experiment, where the position wavefunction of an electron passes through two gaps in a screen and then interferes with itself to ... 05:06: ... we try to measure the final location of the electron on a detector screen, we find that we’re more likely to see it where the ... 05:19: But what decides where the each electron lands? 05:59: The wavefunction of the electron joins the wavefunction of the detector screen at all points, rippling onwards. 06:04: So why does an electron end up looking like a single spot on a screen? 06:11: ... understand that we have to remember that the electron’s wavefunction is only a tiny sliver of a great cosmic wavefunction that ... 06:23: ... we “see” that the electron hit one spot on the screen, what we’re really seeing is a cascade of ... 07:00: ... paths to the electron's wavefuntion not corresponding to our observation of that spot cease to ... 08:08: But imagine you placed detector devices in front of those slits to measure which slit the electron passed though. 08:28: ... the detectors you still have two parts of the same electron’s wavefunction, but now the phase relationship, the correlation between ... 09:54: ... by tallying spots on two sheets of paper - one to your left for electrons that hit the left of the screen, and one to your right for right-landing ... 11:41: ... become entangled with the final state of the electron - correlated with it - one version of you maps only to the right-landing ... 06:23: ... we “see” that the electron hit one spot on the screen, what we’re really seeing is a cascade of ripples ... 05:59: The wavefunction of the electron joins the wavefunction of the detector screen at all points, rippling onwards. 05:19: But what decides where the each electron lands? 08:08: But imagine you placed detector devices in front of those slits to measure which slit the electron passed though. 04:54: ... is in the double-slit experiment, where the position wavefunction of an electron passes through two gaps in a screen and then interferes with itself to produce ... 06:11: ... understand that we have to remember that the electron’s wavefunction is only a tiny sliver of a great cosmic wavefunction that ... 07:00: ... paths to the electron's wavefuntion not corresponding to our observation of that spot cease to ... 08:28: ... the detectors you still have two parts of the same electron’s wavefunction, but now the phase relationship, the correlation between ... 09:54: ... by tallying spots on two sheets of paper - one to your left for electrons that hit the left of the screen, and one to your right for right-landing ... 06:11: ... understand that we have to remember that the electron’s wavefunction is only a tiny sliver of a great cosmic wavefunction that includes every ... 08:28: ... the detectors you still have two parts of the same electron’s wavefunction, but now the phase relationship, the correlation between peaks and ... 07:00: ... paths to the electron's wavefuntion not corresponding to our observation of that spot cease to exist. Many ...
	2021-07-07: Electrons DO NOT Spin 00:00: ... spin. Let’s find out how chasing this elusive little behavior of the electron led us to some of the deepest insights into the nature of the quantum ... 00:47: ... was. The external magnetic field  magnetized the iron, causing the electrons in the iron’s outer shells to align their spins. Those electrons are ... 01:26: ... explanation makes sense if we imagine  electrons like spinning bicycle wheels - or spinning anything. Which might sound ... 02:25: ... in 1915. It wasn’t the first indication of the spin-like properties of electrons. That came from looking  at the specific wavelengths of photons ... 03:20: ... mystery. One explanation that sort of works is  to say that each electron has its own magnetic moment - by itself it acts like a tiny bar magnet. ... 03:48: ... for that to make sense, we really need to think of electrons as balls of spinning charge - but that has huge problems. For example, ... 04:40: ... so electrons aren’t spinning, but somehow  they act like they have angular ... 05:31: A lone electron in the outer shell of the silver atoms grants the atom a magnetic moment. 06:36: ... we know that the electrons have to be aligned up or down only. Let’s send them through a second set ... 07:02: ... not only do electrons have this magnetic  moment without rotation, but the direction of ... 09:59: ... think of electrons as being connected to  all other points in the universe by ... 11:09: ... one way to think about the  angular momentum of an electron is not from classical rotation,   but rather from the fact ... 11:34: ... that you can derive the right values of the  electron spin angular momentum and magnetic moment by looking at the energy and ... 11:44: ... the Dirac spinor aka the electron,   imply that even if the electron is point like, it's angular momentum can arise  from an extended ... 12:02: ... have spin quantum numbers that are half-integers - ½, 3/2, 5/2, etc. The electron itself has spin ½ - so does the proton and ... 13:30: ... Electrons aren’t spinning - they’re doing something far more interesting. The ... 00:00: ... spin. Let’s find out how chasing this elusive little behavior of the electron led us to some of the deepest insights into the nature of the quantum ... 11:34: ... that you can derive the right values of the  electron spin angular momentum and magnetic moment by looking at the energy and ... 11:44: ... the quantum field surrounding  the Dirac spinor aka the electron,   imply that even if the electron is point like, it's angular momentum can ... 00:47: ... was. The external magnetic field  magnetized the iron, causing the electrons in the iron’s outer shells to align their spins. Those electrons are ... 01:26: ... explanation makes sense if we imagine  electrons like spinning bicycle wheels - or spinning anything. Which might sound ... 02:25: ... in 1915. It wasn’t the first indication of the spin-like properties of electrons. That came from looking  at the specific wavelengths of photons ... 03:48: ... for that to make sense, we really need to think of electrons as balls of spinning charge - but that has huge problems. For example, ... 04:40: ... so electrons aren’t spinning, but somehow  they act like they have angular ... 06:36: ... we know that the electrons have to be aligned up or down only. Let’s send them through a second set ... 07:02: ... not only do electrons have this magnetic  moment without rotation, but the direction of ... 09:59: ... think of electrons as being connected to  all other points in the universe by ... 13:30: ... Electrons aren’t spinning - they’re doing something far more interesting. The ... 02:25: ... from looking  at the specific wavelengths of photons emitted when electrons jump between energy levels  in atoms. Peiter Zeeman, working under the ... 03:20: ... So you have the alignment of both the orbital magnetic moment and the electron’s  internal moment contributing new energy ... 04:40: ... de-Haas effect, and it also gives electrons a magnetic field. An electron’s  spin is an entirely quantum mechanical property, and has all the ... 13:00: ... Principle and is responsible for us having a periodic table, for electrons  living in their own energy levels and for matter   actually ... 03:20: ... So you have the alignment of both the orbital magnetic moment and the electron’s  internal moment contributing new energy ... 13:00: ... Principle and is responsible for us having a periodic table, for electrons  living in their own energy levels and for matter   actually having ... 04:40: ... de-Haas effect, and it also gives electrons a magnetic field. An electron’s  spin is an entirely quantum mechanical property, and has all the weirdness ... 07:30: ... two components - motivated by this  ambiguous two-valuedness of electrons.   The wavefunction became a very strange mathematical object called a ...
	2021-06-16: Can Space Be Infinitely Divided? 08:37: ... define the position of an elementary particle - let’s say an electron. To define its position   we need to be able to say that all of ...
	2021-06-09: Are We Running Out of Space Above Earth? 14:49: ... you could somehow get an elementary particle like an electron within that range then perhaps it would be absorbed and the relic would ...
	2021-05-25: What If (Tiny) Black Holes Are Everywhere? 13:57: ... that regular laser light is produced when an incoming photon causes an electron in a crystal to drop in energy to produce an identical photon matched in ...
	2021-04-07: Why the Muon g-2 Results Are So Exciting! 01:41: We've actually talked at about the anomalous magnetic dipole moment before in terms of the electron. 02:22: QED predicts the value for the electrons g-factor that matches experimental measurements to one part in a billion. 02:31: If this works so well for electrons surely it works for other particles too. 02:38: The muon, is a close cousin to the electron identical in all properties besides its heavier mass. 04:00: An electron also has a dipole field and a dipole moment which depends on the electron spin charge and mass. 04:07: But the electron dipole moment is different from the classical one by this factor g. 04:13: For the electron, g is allowed too. 04:15: So the electron responds to a magnetic field twice as strongly compared to what you'd expect for an equivalent classical rotating charge. 04:47: For example, a pair of electrons could repel each other by exchanging one virtual photon, or two virtual photons, or three et cetera. 05:23: We can represent an electron interacting with a magnetic field, with the simplest possible Feynman diagram. 05:31: We have an electron being deflected by a single photon from that field. 05:48: ... next simplest is for the electron to emit a virtual photon just prior to absorbing the magnetic field ... 06:26: And a latest calculated electron g-factor of 2.001159652181643. 06:52: For the electron, the current measurement is precise to one part in a billion. 07:04: The electron is the lightest and most common of the lepton family. 07:20: During their brief existence, they're very similar to electrons. 08:08: So why would we get the wrong value for the muon but not for the electron? 08:16: The muon is 200 times more massive than the electron. 08:31: It's 40,000 times more likely than the electron to encounter, say a virtual Higgs boson, or virtual proton or other hadrons. 04:07: But the electron dipole moment is different from the classical one by this factor g. 06:26: And a latest calculated electron g-factor of 2.001159652181643. 02:38: The muon, is a close cousin to the electron identical in all properties besides its heavier mass. 05:23: We can represent an electron interacting with a magnetic field, with the simplest possible Feynman diagram. 04:15: So the electron responds to a magnetic field twice as strongly compared to what you'd expect for an equivalent classical rotating charge. 04:00: An electron also has a dipole field and a dipole moment which depends on the electron spin charge and mass. 04:56: All those virtual photons could do something weird like momentarily becoming an electron-positron pair. 02:22: QED predicts the value for the electrons g-factor that matches experimental measurements to one part in a billion. 02:31: If this works so well for electrons surely it works for other particles too. 04:47: For example, a pair of electrons could repel each other by exchanging one virtual photon, or two virtual photons, or three et cetera. 07:20: During their brief existence, they're very similar to electrons. 02:22: QED predicts the value for the electrons g-factor that matches experimental measurements to one part in a billion. 02:31: If this works so well for electrons surely it works for other particles too.
	2021-03-23: Zeno's Paradox & The Quantum Zeno Effect 01:27: ... quantum Zeno effect predicts that certain quantum events - like the electrons moving between atomic energy levels, or the decay of atomic nuclei, can ... 01:50: ... of our arrow can only take on specific, discrete values - like how an electron can only occupy certain energy states in an ... 05:17: This has actually been tested for electron transitions in atoms - and I’ll tell you about the experiments in a minute. 05:37: ... Wayne Itano claimed to have demonstrated it in an experiment by halting electron energy ... 06:00: A constant radio-frequency field is tuned to cause electrons to oscillate smoothly between two energy levels - call them 1 and 2. 06:09: Just like our quantum arrow, sometimes an electron is in state 1, sometimes state 2, but in between it’s a smoothly-varying superposition of both. 06:25: ... the electron is in state 1 when the laser pulse hits, it absorbs a laser photon and ... 06:47: But what if the laser hits while the electron is in the middle of a transition - in a superposition of states 1 and 2? 06:53: ... picture, it has to make a choice - the superposition must vanish and the electron will be seen in either state 1 or state ... 07:02: ... measurement should be able to freeze quantum arrows and presumably also electron transitions via the Quantum Zeno ... 09:11: ... that each laser photon perturbed the system in such a way that the electron had an increased chance to jiggle back to its starting ... 10:09: We would say that the wavefunction for different electron states or quantum arrow positions are in phase with each other, or “coherent”. 10:38: ... to get a full quantum Zeno effect - a perfect freezing of your electron or quantum arrow - you need to perfectly measure it, and that means ... 11:32: For example, by forcing the electron or quantum arrow out of its superposition. 05:37: ... Wayne Itano claimed to have demonstrated it in an experiment by halting electron energy ... 10:09: We would say that the wavefunction for different electron states or quantum arrow positions are in phase with each other, or “coherent”. 05:17: This has actually been tested for electron transitions in atoms - and I’ll tell you about the experiments in a minute. 07:02: ... measurement should be able to freeze quantum arrows and presumably also electron transitions via the Quantum Zeno ... 01:27: ... quantum Zeno effect predicts that certain quantum events - like the electrons moving between atomic energy levels, or the decay of atomic nuclei, can ... 06:00: A constant radio-frequency field is tuned to cause electrons to oscillate smoothly between two energy levels - call them 1 and 2. 01:27: ... quantum Zeno effect predicts that certain quantum events - like the electrons moving between atomic energy levels, or the decay of atomic nuclei, can be ...
	2021-02-24: Does Time Cause Gravity? 07:05: Like - what about a particle with no size - supposedly point-like particles like electrons, quarks, etc.
	2021-01-26: Is Dark Matter Made of Particles? 11:12: ... like electrons and antielectrons, or positrons, interact very strongly via the ...
	2021-01-12: What Happens During a Quantum Jump? 00:36: ... comes from the idea that electrons in atoms jump randomly and instantaneously from one orbit or energy ... 01:37: ... placed a similar restriction on atoms - he required that electron energy levels were quantized - could only have very specific energies ... 01:49: Electrons would then jump between energy levels by emitting or absorbing a photon that corresponded to the difference in energy. 02:50: The electron goes from one energy level to the other without moving in between. 05:01: ... as an irreducible energy packet, and even dismissed the notion that electrons transitioned between discrete energy ... 05:19: An atomic electron could then be considered a superposition of multiple vibrational modes. 05:24: ... that meant the electron could transition smoothly through a series of intermediate states during ... 05:49: As he put it, “we never experiment with just one electron or atom. 06:28: ... a frequency exactly tuned to the energy difference between two of its electron levels - call them 1 and ... 06:41: If the electron is in level 1, it should jump to level 2 by absorbing a photon from the laser light. 06:46: If the electron then falls back to level 1 it should emit an identical photon in a random direction. 06:52: For the right choice of energy levels, this should happen extremely quickly - the electron should become locked between the two levels. 06:59: In the 1986 experiments, the electron in the trapped atom jumped between levels something like 100 million times per second. 07:25: Level 3 is far more stable than level 2 - an electron that finds itself there may take many seconds to drop back down. 07:37: Now flash a second laser with frequency tuned to take the electron from level 1 to level 3. 07:43: Suddenly the atom goes dark - the fluorescence stops, because the electron is stuck in level 3 and no longer available to cycle between 1 and 2. 07:52: Then, after a period of time, the electron decays and fluorescence starts again. 08:02: And the downward jumps when the electron decayed out of level 3 appeared to occur at completely random times. 08:16: ... there was no way to tell whether it was instantaneous, or whether the electron passed through some intermediate states during the jump Fast forward ... 08:02: And the downward jumps when the electron decayed out of level 3 appeared to occur at completely random times. 07:52: Then, after a period of time, the electron decays and fluorescence starts again. 01:37: ... placed a similar restriction on atoms - he required that electron energy levels were quantized - could only have very specific energies that ... 06:28: ... a frequency exactly tuned to the energy difference between two of its electron levels - call them 1 and ... 08:16: ... there was no way to tell whether it was instantaneous, or whether the electron passed through some intermediate states during the jump Fast forward another ... 00:36: ... comes from the idea that electrons in atoms jump randomly and instantaneously from one orbit or energy ... 01:49: Electrons would then jump between energy levels by emitting or absorbing a photon that corresponded to the difference in energy. 05:01: ... as an irreducible energy packet, and even dismissed the notion that electrons transitioned between discrete energy ...
	2020-12-22: Navigating with Quantum Entanglement 05:00: An electron, for example, can be thought of as a spinning charge, and magnetic fields can cause that spin to flip direction. 05:08: ... needle aure ferromagnets, and their magnetic fields come from countless electrons with aligned ... 05:17: External magnetic fields tug on those electrons resulting in a force that can swivel the compass needle. 05:23: ... you need a lot of electrons to register Earth’s extremely weak field - far more than you could fit ... 05:38: ... studying “radical pairs.” A radical is any atom or molecule with a lone electron in an outermost or valence ... 06:00: Their unpaired valence electrons are entangled. 06:29: The entangled properties are the quantum spins of the two valence electrons in two separate radical molecules. 06:46: We don't know which electron is up or down, and this is undefinedness is part of the whole entanglement deal. 06:58: ... other three states are when the electrons have the same spin direction - either both up, both down, or a quantum ... 07:10: ... you have just one radical, its valence electron spin tends to stay fixed until disturbed by its environment. And Earth's ... 07:41: ... the system will spend more time in the triplet state - with both electron spins aligned in the same direction, and less in the singlet state where ... 07:53: ... so we have a mechanism to influence two tiny electrons - but a few questions remain: how is the radical pair produced, how long ... 08:20: When light hits the protein, it knocks an electron off an attached molecule that goes onto an adjacent molecule. 08:36: But there’s the key - those byproducts are sensitive to the spin state of the valence electrons at the time of the reaction. 10:40: ... for example, the valence electrons were just interacting due to their magnetic fields - so-called spin-spin ... 07:10: ... you have just one radical, its valence electron spin tends to stay fixed until disturbed by its environment. And Earth's ... 07:41: ... the system will spend more time in the triplet state - with both electron spins aligned in the same direction, and less in the singlet state where they ... 07:53: ... by Earth's magnetic field, and how does the simple slipping of electron spins go on to give the bird ... 07:41: ... the system will spend more time in the triplet state - with both electron spins aligned in the same direction, and less in the singlet state where they have ... 05:08: ... needle aure ferromagnets, and their magnetic fields come from countless electrons with aligned ... 05:17: External magnetic fields tug on those electrons resulting in a force that can swivel the compass needle. 05:23: ... you need a lot of electrons to register Earth’s extremely weak field - far more than you could fit ... 06:00: Their unpaired valence electrons are entangled. 06:29: The entangled properties are the quantum spins of the two valence electrons in two separate radical molecules. 06:58: ... other three states are when the electrons have the same spin direction - either both up, both down, or a quantum ... 07:53: ... so we have a mechanism to influence two tiny electrons - but a few questions remain: how is the radical pair produced, how long ... 08:36: But there’s the key - those byproducts are sensitive to the spin state of the valence electrons at the time of the reaction. 10:40: ... for example, the valence electrons were just interacting due to their magnetic fields - so-called spin-spin ... 07:53: ... so we have a mechanism to influence two tiny electrons - but a few questions remain: how is the radical pair produced, how long ...
	2020-12-15: The Supernova At The End of Time 01:39: ... itself against gravitational collapse by the pressure exerted by its electrons ... 01:48: But its electrons have been vanishing for aeons. 02:27: And what’s happening to their electrons? 03:43: ... matter - degenerate matter - in which atoms are stripped of their electrons, and then those electrons are crammed so close together that all possible ... 03:58: Now electrons can’t overlap - can’t occupy identical quantum states - a weird quantum fact that had only been recently discovered. 04:07: Unable to get any closer, the electrons in degenerate matter exert a powerful outward pressure - electron degeneracy pressure. 04:55: Its core would collapse until halted by electron degeneracy pressure. 05:37: And in the extreme density of a white dwarf, electrons would indeed be traveling fast enough for relativity to change the physics. 05:59: The star’s own electrons would be driven into its nuclei in a process called electron capture. 06:06: ... fewer electrons means less electron degeneracy pressure, which means the star begins to ... 07:10: In regular crystals, atoms or molecules are bonded into a lattice by sharing their electrons. 07:16: In a white dwarf, the nuclei can never recapture their electrons to become atoms again. 07:20: The electrons remain as a hot, degenerate plasma and continue their work of keeping the star from collapsing. 07:27: Meanwhile the nuclei stop interacting with the electrons and slow down as they cool. 10:02: It depends on the number of electrons relative to the mass of the star. 10:29: But that emitted positron is the antimatter counterpart of the electrons that are supporting the star from the collapse. 10:36: It immediately annihilates with one of those electrons, depleting the star’s supply. 05:59: The star’s own electrons would be driven into its nuclei in a process called electron capture. 04:07: Unable to get any closer, the electrons in degenerate matter exert a powerful outward pressure - electron degeneracy pressure. 04:55: Its core would collapse until halted by electron degeneracy pressure. 06:06: ... fewer electrons means less electron degeneracy pressure, which means the star begins to collapse, which means more ... 04:07: Unable to get any closer, the electrons in degenerate matter exert a powerful outward pressure - electron degeneracy pressure. 04:55: Its core would collapse until halted by electron degeneracy pressure. 06:06: ... fewer electrons means less electron degeneracy pressure, which means the star begins to collapse, which means more electrons ... 01:39: ... itself against gravitational collapse by the pressure exerted by its electrons ... 01:48: But its electrons have been vanishing for aeons. 02:27: And what’s happening to their electrons? 03:43: ... matter - degenerate matter - in which atoms are stripped of their electrons, and then those electrons are crammed so close together that all possible ... 03:58: Now electrons can’t overlap - can’t occupy identical quantum states - a weird quantum fact that had only been recently discovered. 04:07: Unable to get any closer, the electrons in degenerate matter exert a powerful outward pressure - electron degeneracy pressure. 05:37: And in the extreme density of a white dwarf, electrons would indeed be traveling fast enough for relativity to change the physics. 05:59: The star’s own electrons would be driven into its nuclei in a process called electron capture. 06:06: ... fewer electrons means less electron degeneracy pressure, which means the star begins to ... 07:10: In regular crystals, atoms or molecules are bonded into a lattice by sharing their electrons. 07:16: In a white dwarf, the nuclei can never recapture their electrons to become atoms again. 07:20: The electrons remain as a hot, degenerate plasma and continue their work of keeping the star from collapsing. 07:27: Meanwhile the nuclei stop interacting with the electrons and slow down as they cool. 10:02: It depends on the number of electrons relative to the mass of the star. 10:29: But that emitted positron is the antimatter counterpart of the electrons that are supporting the star from the collapse. 10:36: It immediately annihilates with one of those electrons, depleting the star’s supply. 06:06: ... pressure, which means the star begins to collapse, which means more electrons driven into nuclei, and so in in a runaway ... 10:02: It depends on the number of electrons relative to the mass of the star. 07:20: The electrons remain as a hot, degenerate plasma and continue their work of keeping the star from collapsing.
	2020-11-18: The Arrow of Time and How to Reverse It 02:08: ... OK, so imagine two particles moving towards each other - let’s say, electrons. They move up in time and towards each other in space. When they get ... 02:31: ... laws of motion combined with Coulomb’s law perfectly describe how the electrons’ positions change over time. But if we flip this diagram on its head - ... 03:12: ... between objects. For example, kinetic energy is transferred between our electrons when they ... 03:53: ... shared out. It’s very unlikely that through random collisions, half the electrons would get all the energy and the other half end up with ... 02:08: ... OK, so imagine two particles moving towards each other - let’s say, electrons. They move up in time and towards each other in space. When they get ... 02:31: ... laws of motion combined with Coulomb’s law perfectly describe how the electrons’ positions change over time. But if we flip this diagram on its head - ... 03:12: ... between objects. For example, kinetic energy is transferred between our electrons when they ... 03:53: ... shared out. It’s very unlikely that through random collisions, half the electrons would get all the energy and the other half end up with ... 02:31: ... diagram on its head - reverse the flow of time, it still looks like two electrons bouncing off each other. The same equations perfectly describe the bounce in both ...
	2020-11-04: Electroweak Theory and the Origin of the Fundamental Forces 01:11: Beta decay is when a neutron turns into a proton by emitting an electron and neutrino. 01:17: The electron was called a beta particle by Ernest Rutherford back in 1899 before we knew that these things were electrons. 01:36: While the brand new field of quantum mechanics could describe the behaviour of electrons, nuclear processes remained mysterious. 02:02: So an ingoing neutron is directly converted into the outgoing proton, electron and neutrino, with all the conservation laws satisfied. 01:17: The electron was called a beta particle by Ernest Rutherford back in 1899 before we knew that these things were electrons. 01:36: While the brand new field of quantum mechanics could describe the behaviour of electrons, nuclear processes remained mysterious.
	2020-09-28: Solving Quantum Cryptography 15:49: Electrons and quarks are electric monopoles.
	2020-09-08: The Truth About Beauty in Physics 08:11: The resulting Dirac equation is the entirely correct relativistic quantum description of the behavior of the electron. 08:35: ... allowed the electron to have states with negative energy levels - not technically possible, ... 13:50: Basically, why do we see specific wavelengths missing from starlight due to electrons absorbing those wavelengths in atoms? 13:58: Shouldn't those same electrons then drop back down in energy level, emitting the same wavelengths they absorbed? 15:22: The Belle II experiment that just started taking data on Japan's superKEKB electron-positron collider. 13:50: Basically, why do we see specific wavelengths missing from starlight due to electrons absorbing those wavelengths in atoms? 13:58: Shouldn't those same electrons then drop back down in energy level, emitting the same wavelengths they absorbed? 13:50: Basically, why do we see specific wavelengths missing from starlight due to electrons absorbing those wavelengths in atoms?
	2020-09-01: How Do We Know What Stars Are Made Of? 03:56: One of the most severe is that the Sun is full of free electrons - electrons that were stripped from their atoms due to the intense heat. 04:03: Electrons deflect the path of a photon very easily. 04:07: So any given photon has to bounce its way between many electrons before finding its way to the surface. 04:22: Once it gets close to the surface, material is much less dense, so there are fewer free electrons to do the scattering. 04:42: As temperature drops, it becomes possible for some electrons to be captured by nuclei to form atoms. 04:49: And if free electrons are good at stopping photons in their tracks, these atoms are even better. 04:54: An atom can absorb a photon if doing so would cause one of its electrons to jump up to a higher energy level. 05:02: The energy of the photon and the energy of the electron jump have to be exactly the same. 06:38: In energetic environments like the Sun, electrons are regularly kicked free from their atoms. 06:45: ... changes the energy levels of the electrons that remain, resulting in a different set of possible absorption lines ... 05:02: The energy of the photon and the energy of the electron jump have to be exactly the same. 03:56: One of the most severe is that the Sun is full of free electrons - electrons that were stripped from their atoms due to the intense heat. 04:03: Electrons deflect the path of a photon very easily. 04:07: So any given photon has to bounce its way between many electrons before finding its way to the surface. 04:22: Once it gets close to the surface, material is much less dense, so there are fewer free electrons to do the scattering. 04:42: As temperature drops, it becomes possible for some electrons to be captured by nuclei to form atoms. 04:49: And if free electrons are good at stopping photons in their tracks, these atoms are even better. 04:54: An atom can absorb a photon if doing so would cause one of its electrons to jump up to a higher energy level. 06:38: In energetic environments like the Sun, electrons are regularly kicked free from their atoms. 06:45: ... changes the energy levels of the electrons that remain, resulting in a different set of possible absorption lines ... 03:56: One of the most severe is that the Sun is full of free electrons - electrons that were stripped from their atoms due to the intense heat. 04:03: Electrons deflect the path of a photon very easily.
	2020-08-24: Can Future Colliders Break the Standard Model? 02:53: Its four meter ring collided electrons and positrons. 02:57: ... quickly followed with their VEP-1, which was smaller but collided electrons with one another to get a thousand times higher luminosity than ... 03:40: Graduating from electrons and positrons, in 1971 physicists started smashing protons together at CERN’s Intersecting Storage Rings facility. 09:11: ... be smashing protons like the LHC does, but to start with it’ll collide electrons and positrons with the express intention of making as many Higgs ... 11:26: It will smack electrons into protons and other nucleons to probe the details structure and interactions between quarks. 15:59: ... mass of a white dwarf before crushing gravitational pressure causes electrons to be pounded into protons to form neutrons, causing the thing to ... 03:19: The Americans soon followed up with a 12 meter electron-electron collider with a similar luminosity to VEP-1 but higher energies than even the AdA. 11:14: But the next big-ish US collider will most likely be the Electron-Ion Collider. 09:25: ... remember that the first particle colliders worked with electron-positron beams, and for good reason: they are easier to work with compared to ... 02:53: Its four meter ring collided electrons and positrons. 02:57: ... quickly followed with their VEP-1, which was smaller but collided electrons with one another to get a thousand times higher luminosity than ... 03:40: Graduating from electrons and positrons, in 1971 physicists started smashing protons together at CERN’s Intersecting Storage Rings facility. 09:11: ... be smashing protons like the LHC does, but to start with it’ll collide electrons and positrons with the express intention of making as many Higgs ... 11:26: It will smack electrons into protons and other nucleons to probe the details structure and interactions between quarks. 15:59: ... mass of a white dwarf before crushing gravitational pressure causes electrons to be pounded into protons to form neutrons, causing the thing to ...
	2020-08-17: How Stars Destroy Each Other 05:05: ... nuclei are no longer distinct - instead they meld together, protons and electrons combine to become neutrons, and you’re left with a ball of hyperdense ...
	2020-08-10: Theory of Everything Controversies: Livestream 00:00: ... the y structure would have a metric and then it could have things like electrons and muons and neutrinos and the like but in fact it points off so ...
	2020-07-28: What is a Theory of Everything: Livestream 00:00: ... the realm of the smallest possible stuff the quarks and gluons and electrons and things that make up you and everything around you and you think ...
	2020-07-20: The Boundary Between Black Holes & Neutron Stars 12:52: However it never actually becomes impossible to keep charging up a black hole if you can put enough energy behind your electron beam.
	2020-07-08: Does Antimatter Explain Why There's Something Rather Than Nothing? 00:22: ... identical in every way, but with the opposite charge and spin. An electron has a positron; a proton, an anti-proton; and so on. And when a particle ... 06:27: ... of just a single anti-proton plus a positron, instead of the proton + electron of regular hydrogen. In 1999 , NASA estimated that when taking all ...
	2020-06-30: Dissolving an Event Horizon 09:51: ... electrons have very tiny masses for comparatively large charge - just factoring ... 10:15: And there’s an enormous amount of energy in the electric field of all those electrons that you smooshed together into the black hole. 14:17: ... Electrons, for example, supposedly have “zero size”, but they also have something ... 14:31: That’s like another type of size, and it makes a big difference if you’re a millimeter from an electron versus a trillion light years. 09:51: ... electrons have very tiny masses for comparatively large charge - just factoring ... 10:15: And there’s an enormous amount of energy in the electric field of all those electrons that you smooshed together into the black hole. 14:17: ... Electrons, for example, supposedly have “zero size”, but they also have something ... 09:51: ... very tiny masses for comparatively large charge - just factoring the electrons mass, it should be easy to send a black hole over the extremal limit by ...
	2020-06-15: What Happens After the Universe Ends? 06:36: ... if you have even a single electron in the universe you can build a clock and can tell the difference ... 07:16: ... but it may be the case that we’re left with only a universe of photons, electrons and positrons, and neutrinos, as well as gravitons - the quantum ... 07:38: Penrose speculates that mass itself may not be a fundamental property, and may eventually decay to leave massless electrons, etc. 07:46: The standard model of particle physics predicts eternal electrons. 07:53: ... those particles with quantum fields - the Higgs field in the case of the electron. ... 08:39: And that’s precisely true for things like quarks and electrons, which gain their masses from interactions with the Higgs field. 07:16: ... but it may be the case that we’re left with only a universe of photons, electrons and positrons, and neutrinos, as well as gravitons - the quantum ... 07:38: Penrose speculates that mass itself may not be a fundamental property, and may eventually decay to leave massless electrons, etc. 07:46: The standard model of particle physics predicts eternal electrons. 08:39: And that’s precisely true for things like quarks and electrons, which gain their masses from interactions with the Higgs field.
	2020-04-28: Space Time Livestream: Ask Matt Anything 00:00: ... theories I think they're so colorful and cool you know the the one electron universe of John Archibald wheeler or Paul Dirac's electron see I'm ...
	2020-04-22: Will Wormholes Allow Fast Interstellar Travel? 15:35: ... of the space is filled with ionized hydrogen - protons stripped of their electrons, with densities between 1 particle per cubic centimeter and 1 particle ...
	2020-04-14: Was the Milky Way a Quasar? 05:29: Extremely energetic electrons interact with lower-energy light, boosting that light to the much more energetic gamma ray regime. 05:36: And so that’s what we’re seeing here - light bounced off extremely high energy electrons within the vast bubbles. 05:42: It’s estimated that the energy contained in this ocean of electrons is equivalent to that released by 100,000 supernova explosions. 11:16: ... also likely generated by electrons, but in this case, the electrons are accelerated by magnetic fields and ... 05:29: Extremely energetic electrons interact with lower-energy light, boosting that light to the much more energetic gamma ray regime. 05:36: And so that’s what we’re seeing here - light bounced off extremely high energy electrons within the vast bubbles. 05:42: It’s estimated that the energy contained in this ocean of electrons is equivalent to that released by 100,000 supernova explosions. 11:16: ... also likely generated by electrons, but in this case, the electrons are accelerated by magnetic fields and ... 05:29: Extremely energetic electrons interact with lower-energy light, boosting that light to the much more energetic gamma ray regime.
	2020-03-31: What’s On The Other Side Of A Black Hole? 12:02: ... of the other. That's maximal entanglement for the spin state. If the electron then interacts with, say, a photon so that the photon and electron spin ...
	2020-03-16: How Do Quantum States Manifest In The Classical World? 03:12: ... direction, as you’d expect for a classical spinning object. Instead the electron will randomly shift ot having left or right ... 04:28: ... or EPR paradox. A high energy photon decays into an electron and a positron. These particles both have spin values of 1/2, but the ... 05:32: ... crazy thing is if I measure the spin of one particle - say the electron - my choice of measurement basis defines the spin of the positron. If I ... 06:24: ... our measuring device - it’s a series of magnets designed to deflect the electron based on its up or down spin. Spin-up electrons are deflected upwards, ... 07:15: ... the electron passes close to the atom, the atom flips between two states. The nature ... 07:37: ... the up path of our device, and we start it out in the off state. If our electron takes the up path it flips the atom to the on state. If it takes the ... 08:44: ... would instantaneously influence the combined state of the atom and the electron. Or we could measure the atom’s state, which would influence the electron ... 09:19: See, the entangled atom now holds information about the electron’s left-right spin. 09:28: ... that information used to be expressible as a superposition of the electron’s up-down status, now it’s hidden in a superposition of the atom’s on-off ... 05:32: ... crazy thing is if I measure the spin of one particle - say the electron - my choice of measurement basis defines the spin of the positron. If I ... 06:24: ... our measuring device - it’s a series of magnets designed to deflect the electron based on its up or down spin. Spin-up electrons are deflected upwards, ... 07:15: ... the electron passes close to the atom, the atom flips between two states. The nature of ... 07:37: ... the electron’s path, and so learn its spin. But what happens after the electron passes through our device. Does its spin count as being measured? Does the ... 07:15: ... the electron passes close to the atom, the atom flips between two states. The nature of those two ... 07:37: ... the up path of our device, and we start it out in the off state. If our electron takes the up path it flips the atom to the on state. If it takes the down path ... 06:24: ... designed to deflect the electron based on its up or down spin. Spin-up electrons are deflected upwards, spin-down electrons are deflected down. Then both ... 07:15: ... from the electron. One possibility would be that the spin of one of the electrons inside the atom gets flipped. But for simplicity, we’ll call these two ... 07:37: ... the off state. We should be able to just look at the atom to learn the electron’s path, and so learn its spin. But what happens after the electron passes ... 08:44: ... magnetic fields, which only affect the vertical component of the electron’s spin, we haven’t even defined the basis that the electron’s spin as up ... 09:19: See, the entangled atom now holds information about the electron’s left-right spin. 09:28: ... that information used to be expressible as a superposition of the electron’s up-down status, now it’s hidden in a superposition of the atom’s on-off ... 07:15: ... from the electron. One possibility would be that the spin of one of the electrons inside the atom gets flipped. But for simplicity, we’ll call these two states ... 09:19: See, the entangled atom now holds information about the electron’s left-right spin. 06:24: ... to their original straight path. By itself this device isn’t useful - electrons passing through will still be in a superposition of spin states - both up and ... 07:37: ... the off state. We should be able to just look at the atom to learn the electron’s path, and so learn its spin. But what happens after the electron passes ... 08:44: ... magnetic fields, which only affect the vertical component of the electron’s spin, we haven’t even defined the basis that the electron’s spin as up or ... 07:37: ... AND electron down, atom off. The atom’s state is now correlated with the electron’s state and the two are entangled. Which means the atom’s state is also ... 09:28: ... that information used to be expressible as a superposition of the electron’s up-down status, now it’s hidden in a superposition of the atom’s on-off status. ...
	2020-02-24: How Decoherence Splits The Quantum Multiverse 09:43: ... the photon energizes electrons in a pixel on the screen, which results in an electrical signal passing ... 10:01: ... can imagine separate possible histories continue, now with electrons simultaneously excited and not excited across the screen, and ... 10:20: The electrons in the detector and in the circuits will be at different locations and will have different energies. 09:43: ... the photon energizes electrons in a pixel on the screen, which results in an electrical signal passing ... 10:01: ... can imagine separate possible histories continue, now with electrons simultaneously excited and not excited across the screen, and ... 10:20: The electrons in the detector and in the circuits will be at different locations and will have different energies. 10:01: ... can imagine separate possible histories continue, now with electrons simultaneously excited and not excited across the screen, and superpositions of signals ...
	2020-02-18: Does Consciousness Influence Quantum Mechanics? 02:04: It goest like this: A single electron is shot at a pair of slits. It passes through and is registered on a detector screen on the other side. 02:13: When multiple electrons are shot one after the other, they form a series of bands. 02:23: But that’s weird because this interference pattern seems to guide the path of each electron independently of the others. 02:31: Each solitary electron must know the entire wave pattern - which means it must, in some sense, travel through both slits. 02:40: ... interpretation explains the result of this experiment by saying that the electron does NOT travel as a particle or as a physical wave along one of these ... 02:58: That probability wave defines the location of the electron at any point IF you try to measure it. 03:05: The Copenhagen interpretation states that, prior to measurement, it’s meaningless to talk about a real, physical state for the electron. 03:20: ... - it goes from a cloud of possible final destinations for the electron to a more or less definite spot on the detector ... 03:56: ... electron wavefunction passes through both slits, reaches the electronic detector, ... 04:05: ... second electron begins a cascade - an electrical impulse that travels along circuits to ... 04:17: ... in other parts of the brain result in a subjective sense of the original electron's chosen destination on the ... 04:56: Probably not as soon as our electron wavefunction reaches the detector. 04:59: The first electron to become excited in the detector is also a quantum object. 05:05: That means the traveling electron’s wavefunction will just become mixed with the wavefunctions of all electrons that it could possibly excite. 05:14: ... get what we call a superposition of states: a wavefunction in which an electron at every location on the detector screen is simultaneously excited and ... 06:55: So we have this weird moment - somewhere between the landing of that electron on the screen and your friend telling you the result. 11:18: A single electron reaches the detector screen and you both learn its location at the same time. 12:32: ... understand what happens to these multiple alternate histories after the electron wavefunction reaches the detector - and why these histories stop ... 04:05: ... computer, which updates an image on a computer screen to show where the electron hit. ... 02:23: But that’s weird because this interference pattern seems to guide the path of each electron independently of the others. 11:18: A single electron reaches the detector screen and you both learn its location at the same time. 03:56: ... electron wavefunction passes through both slits, reaches the electronic detector, and there it ... 04:56: Probably not as soon as our electron wavefunction reaches the detector. 12:32: ... understand what happens to these multiple alternate histories after the electron wavefunction reaches the detector - and why these histories stop communicating with ... 03:56: ... electron wavefunction passes through both slits, reaches the electronic detector, and there it ... 04:56: Probably not as soon as our electron wavefunction reaches the detector. 12:32: ... understand what happens to these multiple alternate histories after the electron wavefunction reaches the detector - and why these histories stop communicating with each ... 03:56: ... electron wavefunction passes through both slits, reaches the electronic detector, and there it excites a second electron somewhere on the ... 02:13: When multiple electrons are shot one after the other, they form a series of bands. 04:17: ... in other parts of the brain result in a subjective sense of the original electron's chosen destination on the ... 05:05: That means the traveling electron’s wavefunction will just become mixed with the wavefunctions of all electrons that it could possibly excite. 04:17: ... in other parts of the brain result in a subjective sense of the original electron's chosen destination on the ... 05:05: That means the traveling electron’s wavefunction will just become mixed with the wavefunctions of all electrons that it could possibly excite.
	2020-02-11: Are Axions Dark Matter? 06:54: ... be extreme ly light - a tiny fraction of the mass of the already tiny electron. ... 08:58: ... in the core of the sun. There, X-rays are constantly bouncing off electrons and protons in the presence of strong electromagnetic fields. Perfect ... 12:47: ... of those particles are indistinguishable from each other - swapping two electrons or two photons doesn't change anything, so that number might be an over ... 08:58: ... in the core of the sun. There, X-rays are constantly bouncing off electrons and protons in the presence of strong electromagnetic fields. Perfect ... 12:47: ... of those particles are indistinguishable from each other - swapping two electrons or two photons doesn't change anything, so that number might be an over ...
	2020-02-03: Are there Infinite Versions of You? 15:00: Imagine an interaction where an electron emits a virtual photon which then deflects another particles - say, a proton. 15:08: ... the same interaction as if the proton emitted the photon to deflect the electron - in other words, the direction of the flow of time is irrelevant from ... 15:00: Imagine an interaction where an electron emits a virtual photon which then deflects another particles - say, a proton.
	2020-01-27: Hacking the Nature of Reality 00:14: The year is 1925 and the young Werner Heisenberg is striving to understand the mechanics of the newly-discovered electron orbitals of hydrogen. 00:43: ... - in this case, the mysterious frequencies of light produced as electrons jump between ... 03:14: At the beginning of the 1960s the atom was understood as fuzzy, quantum electron orbits surrounding a nucleus of protons and neutrons. 03:24: Those nuclear particles were originally thought to be elementary - to have no internal structure, just like the electron. 00:14: The year is 1925 and the young Werner Heisenberg is striving to understand the mechanics of the newly-discovered electron orbitals of hydrogen. 03:14: At the beginning of the 1960s the atom was understood as fuzzy, quantum electron orbits surrounding a nucleus of protons and neutrons. 00:43: ... - in this case, the mysterious frequencies of light produced as electrons jump between ...
	2020-01-20: Solving the Three Body Problem 13:37: ... what it means for a neutrino to go with a particular lepton, meaning electron, muon or tau. It turns out that over short distances and before neutrinos ...
	2020-01-06: How To Detect a Neutrino 01:31: ♪ ♪ DR. DON (voiceover): That's the same family as the familiar electron ♪ ♪ and it's heavier cousins the muon and tau particle. 01:42: ♪ ♪ So we have the electron neutrino, ♪ ♪ muon neutrino, and tau neutrino. 05:47: ♪ ♪ Those particles then travel through the liquid argon knocking electrons free from atoms. 05:58: ... ♪ That draws these free electrons to the walls of the tank, which lets us trace out the path of the ... 06:15: ... source produces only muon neutrinos, ♪ ♪ so if we detect a tau or electron neutrino, then we've seen neutrino ... 05:58: ... and that includes the flavour of the neutrino that caused it - be it an electron, muon, or tau ... 01:42: ♪ ♪ So we have the electron neutrino, ♪ ♪ muon neutrino, and tau neutrino. 06:15: ... source produces only muon neutrinos, ♪ ♪ so if we detect a tau or electron neutrino, then we've seen neutrino ... 05:47: ♪ ♪ Those particles then travel through the liquid argon knocking electrons free from atoms. 05:58: ... ♪ That draws these free electrons to the walls of the tank, which lets us trace out the path of the ... 05:47: ♪ ♪ Those particles then travel through the liquid argon knocking electrons free from atoms.
	2019-12-17: Do Black Holes Create New Universes? 00:30: Why, for example, are the fundamental constants - like the mass of the electron or the strength of the forces - just right for the emergence of life?
	2019-11-11: Does Life Need a Multiverse to Exist? 04:02: In our universe, quarks tend to stick together to form protons and neutrons, which stick together and attract electrons to form atoms. 04:10: ... atom types - which interact with each other according to their complex electron shell ... 08:18: For example, if quarks or electrons had significantly different masses we’d once again be in a chemistry-free cosmos. 04:10: ... atom types - which interact with each other according to their complex electron shell ... 04:02: In our universe, quarks tend to stick together to form protons and neutrons, which stick together and attract electrons to form atoms. 08:18: For example, if quarks or electrons had significantly different masses we’d once again be in a chemistry-free cosmos.
	2019-09-23: Is Pluto a Planet? 00:39: Chemists group elements on the periodic table, those groups exhibit similar chemical behavior that reflect outer-shell electron number.
	2019-09-03: Is Earth's Magnetic Field Reversing? 03:15: Alternatively, flows of many charged particles like electrons – so electrical currents - can produce magnetic fields. 05:32: In that motion I just described, electrons and nuclei should all be moving together – so no electrical current. 03:15: Alternatively, flows of many charged particles like electrons – so electrical currents - can produce magnetic fields. 05:32: In that motion I just described, electrons and nuclei should all be moving together – so no electrical current.
	2019-08-06: What Caused the Big Bang? 10:26: ... decay into the familiar particles of the standard model - quarks, electrons, ...
	2019-07-15: The Quantum Internet 09:07: ... a quantum state between a photon and a matter particle – say, an electron whose up or down spin direction can be entangled with the polarization ... 09:27: ... a kind of quantum atomic disk drive, or the spin-state of a single electron in a nitrogen atom embedded in diamond ... 12:15: ... emit a very high energy gamma ray, and that gamma radiation can fry bomb electronics and is relatively easily ... 14:07: ... unstable and the extra neutron quickly decays into a proton, emitting an electron and a neutrino, bumping it one up on the periodic ... 12:15: ... emit a very high energy gamma ray, and that gamma radiation can fry bomb electronics and is relatively easily ...
	2019-06-06: The Alchemy of Neutron Star Collisions 02:47: ... rapidly undergo beta decay transforming into a proton after ejecting an electron and a neutrino the droplets are now essentially nuclei albeit hopelessly ... 12:15: ... of you would: "if the universe was transparent before recombination when electrons were free of their atoms and so could block the paths of photons then it ... 13:02: ... a factor of a hundred at the beginning of re-ionization. And so electrons were more spread out the density was 100^3 times lower than at ... 02:47: ... provides the mechanism for their escape the beta decay releases both electrons and neutrinos in fact a wind of neutrinos so intense that it drives ... 12:15: ... of you would: "if the universe was transparent before recombination when electrons were free of their atoms and so could block the paths of photons then it ... 13:02: ... a factor of a hundred at the beginning of re-ionization. And so electrons were more spread out the density was 100^3 times lower than at ... 12:15: ... paths of photons then it was transparent during the dark ages because electrons bound in atoms don't block most of the light then after the universe was ... 02:47: ... reasonably asks, "why is it called recombination? After all weren't electrons combining with nuclei for the very first time, so why not just combination?" - ...
	2019-05-16: The Cosmic Dark Ages 01:34: ... the universe was filled with hydrogen and helium atoms stripped of their electrons - in other words, ionized - in the searing heat left by the Big Bang. ... 02:52: ... UV radiation into the surrounding gas and began stripping atoms of their electrons once again. They also died quickly, and their violent supernova ... 05:13: ... types of light. Any photon whose energy happened to exactly match an electron energy transition in the hydrogen atom was in danger of being absorbed. ... 05:45: ... actually talked about the first, so this is just the tl;dr. When the electron in cold hydrogen gas flips its spin direction it either absorbs or emits ... 08:11: ... That’s a hard ultraviolet photon that can be absorbed or emitted when an electron jumps between the ground and second electron orbitals of ... 09:21: ... absorbed. That happens until the epoch of reionization ends. Then, with electrons detached once more from their atoms, there can be no lyman-alpha ... 05:13: ... types of light. Any photon whose energy happened to exactly match an electron energy transition in the hydrogen atom was in danger of being absorbed. Two ... 08:11: ... That’s a hard ultraviolet photon that can be absorbed or emitted when an electron jumps between the ground and second electron orbitals of ... 01:34: ... the universe was filled with hydrogen and helium atoms stripped of their electrons - in other words, ionized - in the searing heat left by the Big Bang. ... 02:52: ... UV radiation into the surrounding gas and began stripping atoms of their electrons once again. They also died quickly, and their violent supernova ... 09:21: ... absorbed. That happens until the epoch of reionization ends. Then, with electrons detached once more from their atoms, there can be no lyman-alpha ... 01:34: ... the universe was filled with hydrogen and helium atoms stripped of their electrons - in other words, ionized - in the searing heat left by the Big Bang. ... 09:21: ... absorbed. That happens until the epoch of reionization ends. Then, with electrons detached once more from their atoms, there can be no lyman-alpha transitions. The ...
	2019-05-09: Why Quantum Computing Requires Quantum Cryptography 11:04: ... a quantum property that is correlated between the two – for example, electrons with opposite spin axes or photons with 90-degree ...
	2019-05-01: The Real Science of the EHT Black Hole 07:59: Synchrotron results from electrons spiraling in magnetic fields.
	2019-03-20: Is Dark Energy Getting Stronger? 07:58: ... radiate from the accretion disk, they bump into extremely energetic electrons in this region above the ...
	2019-03-13: Will You Travel to Space? 12:52: ... of songs and artists in every genre from pop, classical, rap, jazz, electronic, country, rock, and more. And this week they have a very mathy episode on ... 13:51: Electrons escape their orbits by quantum tunneling, and protons themselves may eventually decay. 12:52: ... of songs and artists in every genre from pop, classical, rap, jazz, electronic, country, rock, and more. And this week they have a very mathy episode on ... 13:51: Electrons escape their orbits by quantum tunneling, and protons themselves may eventually decay.
	2019-03-06: The Impossibility of Perpetual Motion Machines 13:47: ... a lot from the dust in between the stars, and also from individual electrons either bumping into other charged particles or circling in magnetic ... 14:43: Recombination happened when the universe became cool enough nuclei capture electrons to form the first atoms. 13:47: ... a lot from the dust in between the stars, and also from individual electrons either bumping into other charged particles or circling in magnetic ... 14:43: Recombination happened when the universe became cool enough nuclei capture electrons to form the first atoms.
	2019-02-20: Secrets of the Cosmic Microwave Background 02:05: ... was in plasma form with the simple atomic nuclei stripped of their electrons in that extreme heat in this plasma state, light and matter were locked ...
	2019-02-07: Sound Waves from the Beginning of Time 01:46: ... after the Big Bang, and still so hot that no atoms could form, and electrons buzzed free of their ... 02:01: There's also light, in fact, around a billion photons for every electron. 02:06: but no photon is safe from a free electron. 02:09: Unbound electrons present a huge target to scatter any wavelength of light. 02:17: A photon could barely travel any distance before colliding with an electron. 02:22: The electrons in turn exerted their electromagnetic pool on the nuclei. 05:11: At this temperature, electrons could finally be captured by nuclei and the first true atoms formed. 05:26: ... free electrons were able to interact with any frequency of light, electrons bound into ... 01:46: ... after the Big Bang, and still so hot that no atoms could form, and electrons buzzed free of their ... 02:09: Unbound electrons present a huge target to scatter any wavelength of light. 02:22: The electrons in turn exerted their electromagnetic pool on the nuclei. 05:11: At this temperature, electrons could finally be captured by nuclei and the first true atoms formed. 05:26: ... free electrons were able to interact with any frequency of light, electrons bound into ... 01:46: ... after the Big Bang, and still so hot that no atoms could form, and electrons buzzed free of their ...
	2019-01-16: Our Antimatter, Mirrored, Time-Reversed Universe 00:42: ... that first proved this found that cobalt-60 nuclei decay by splitting an electron out in the opposite direction to their nucleus speed axis but in a ... 01:48: ... that will align with a magnetic field let's say upwards so the decay electrons travel ... 02:02: ... detector is placed to intercept those electrons and the clock ticks with every captured electron. In our reflected clock ... 03:02: ... sure, Feynman - why not! electrons become positronsquarks become anti quarks and vice-versa sending protons ... 01:48: ... that will align with a magnetic field let's say upwards so the decay electrons travel ... 02:02: ... detector is placed to intercept those electrons and the clock ticks with every captured electron. In our reflected clock ... 03:02: ... sure, Feynman - why not! electrons become positronsquarks become anti quarks and vice-versa sending protons ... 01:48: ... that will align with a magnetic field let's say upwards so the decay electrons travel ... 02:02: ... cobalt atoms with their parity inverted counterparts but now the decay electrons travel upwards with the nuclear spin and away from the detector such a clock ... 03:02: ... reflection and once due to the switch to antimatter that leaves the electrons traveling in the original direction down and the clock ticks as normal so even ...
	2018-12-20: Why String Theory is Wrong 04:17: It was an incredible discovery and a beautiful one. It even made a prediction: the ratio between the mass of the electric charge and the electron. 04:26: Assuming the experimentally measured value for the electric charge, the corresponding electron mass should be around five kilograms?
	2018-12-12: Quantum Physics in a Mirror Universe 00:02: ... of cobalt decays via the weak interaction into nickel by emitting an electron and some gamma ray photons and neutrinos the cobalt-60 nucleus also ...
	2018-11-21: 'Oumuamua Is Not Aliens 14:23: As a neutrino travels through empty space, they oscillate between the three types, electron neutrino, muon neutrino, and tau neutrino. 15:07: ... below is incredibly unlikely, hence the hypothesis that it was an electron or muon neutrino that interacted to produce a supersymmetric stau ... 14:23: As a neutrino travels through empty space, they oscillate between the three types, electron neutrino, muon neutrino, and tau neutrino.
	2018-11-14: Supersymmetric Particle Found? 03:52: ... magnetic fields are all expected to blast high energy particles like electrons and atomic nuclei into the ... 05:53: It spots neutrinos when they're decayed or electrons, muons, or tau particles, which in turn produce visible light as they streak through the ice. 08:00: And that's the heavier cousin to the electron. 03:52: ... magnetic fields are all expected to blast high energy particles like electrons and atomic nuclei into the ... 05:53: It spots neutrinos when they're decayed or electrons, muons, or tau particles, which in turn produce visible light as they streak through the ice.
	2018-11-07: Why String Theory is Right 06:36: A while ago, we talked about Paul Dirac developed a wave equation for the electron that took into account Einstein's special theory of relativity. 06:46: It was a mathematical mess until Dirac added some nonsense terms to the electron-wave function that caused a lot of the mess to cancel out.
	2018-10-31: Are Virtual Particles A New Layer of Reality? 02:18: For example, two electrons-- excitations in the electron field-- will repel each other by exchanging energy through the electromagnetic field. 02:30: ... electron jiggles the electromagnetic field, and those jiggles have a back ... 03:25: ... the case of the interacting electrons, you start by saying each electron interacts once with the EM field, ... 05:56: In our first example, we looked at two electrons repelling each other. 06:00: One electron throws a virtual photon at the other one causing them to be deflected from each other like a game of quantum dodgeball. 06:10: What about an electron and a positron? 06:17: Let's look at the fine and diagram of a single virtual photon passing from electron to positron. 06:23: ... possible effect of every possible virtual photon being emitted by the electron and absorbed by the ... 06:39: Their momenta are pointing from positron to electron rather than electron to positron. 06:45: And you also count photons emitted by the positron but pointing away from the electron. 07:57: It can move between our electron and positron even if its momentum is pointing in the wrong direction. 08:31: Bizarrely, you also have to include the case where the electron and the positron totally ignore each other to even see an attractive force. 02:18: For example, two electrons-- excitations in the electron field-- will repel each other by exchanging energy through the electromagnetic field. 03:25: ... the case of the interacting electrons, you start by saying each electron interacts once with the EM field, transferring between them energy momentum and ... 02:30: ... electron jiggles the electromagnetic field, and those jiggles have a back reaction that ... 06:00: One electron throws a virtual photon at the other one causing them to be deflected from each other like a game of quantum dodgeball. 02:18: For example, two electrons-- excitations in the electron field-- will repel each other by exchanging energy through the electromagnetic field. 02:30: ... reaction that jiggles each electron, which in turn affects the way the electrons jiggle the EM field ad ... 03:25: ... the case of the interacting electrons, you start by saying each electron interacts once with the EM field, ... 05:56: In our first example, we looked at two electrons repelling each other. 02:18: For example, two electrons-- excitations in the electron field-- will repel each other by exchanging energy through the electromagnetic field. 02:30: ... reaction that jiggles each electron, which in turn affects the way the electrons jiggle the EM field ad ... 05:56: In our first example, we looked at two electrons repelling each other.
	2018-10-18: What are the Strings in String Theory? 06:48: Niels Bohr came up with the first quantum model for electron orbits by thinking of them as ring-like standing waves around the hydrogen atom. 06:57: But quantum strings are much more ambitious than boring electron orbits. 06:48: Niels Bohr came up with the first quantum model for electron orbits by thinking of them as ring-like standing waves around the hydrogen atom. 06:57: But quantum strings are much more ambitious than boring electron orbits.
	2018-10-10: Computing a Universe Simulation 07:16: For example, a simple quantum system would be a group of electrons with spins pointing up or down, corresponding to a single bit the information each. 07:25: ... the spin of an electron is a change to an orthogonal state, but it can also be thought of as a ... 13:15: But that's radio, which can interact strongly with the rare charged electrons and protons in intergalactic space. 07:16: For example, a simple quantum system would be a group of electrons with spins pointing up or down, corresponding to a single bit the information each. 13:15: But that's radio, which can interact strongly with the rare charged electrons and protons in intergalactic space.
	2018-09-20: Quantum Gravity and the Hardest Problem in Physics 02:58: We already talked about how Paul Dirac fixed part of the problem with a relativistic wave equation for the electron. 05:38: That's why we use electron microscopes or X-rays or even gamma rays to take images of extremely small things. 08:10: For example, classical electromagnetism becomes quantum electrodynamics when you quantize the electron field and the electromagnetic field. 09:33: ... example, in quantum electrodynamics, the electron has a self-interaction due to its electric charge messing with the ... 09:48: ... a complex interaction, like the buzzing electromagnetic field around an electron, with a series of corrections to a simple, well-understood interaction, ... 10:31: ... example, measurement of the mass and charge of an electron renormalizes quantum electrodynamics to allow incredibly precise ... 08:10: For example, classical electromagnetism becomes quantum electrodynamics when you quantize the electron field and the electromagnetic field. 05:38: That's why we use electron microscopes or X-rays or even gamma rays to take images of extremely small things. 10:31: ... example, measurement of the mass and charge of an electron renormalizes quantum electrodynamics to allow incredibly precise calculation of the ...
	2018-09-12: How Much Information is in the Universe? 06:07: Each proton has three quarks, and there are a similar number of electrons. 10:04: Just regular matter like protons, electrons, et cetera. 06:07: Each proton has three quarks, and there are a similar number of electrons. 10:04: Just regular matter like protons, electrons, et cetera.
	2018-08-30: Is There Life on Mars? 07:31: ... decade still until 1996 with the advent of high-resolution scanning electron microscopy and laser mass ...
	2018-08-23: How Will the Universe End? 06:58: The universe will contain only photons, electrons, and black holes. 13:46: OK, onto your comments for last week's episode on the most accurate prediction in all of science, the anomalous magnetic moment of the electron. 13:55: ... start with, a few of you asked how we know that the g-factor of the electron should have been equal to 1 in the classical case and 2 in the quantum ... 14:35: Classically, we assumed the electron was a ball of charged stuff, hence g equals 1. 14:59: That's the classical theory, which is wrong-- and also suggested that electrons should spin faster than light. 15:11: So QED is, if not gospel truth, the most right thing we have for describing electrons." OK, nice knowledge bomb there, Gareth Dean. 15:20: Epsilon Jay asks why electrons are thought of as infinitesimal points. 15:56: But that spatial sprint really just tells us the probability of finding the electron, say, here or here or here. 16:03: If we know with 100% certainty the position of an electron, then the size of its quantum wave function becomes zero. 16:12: But really, in principle, there's no minimum precision with which we can know the electron's location, so there's no minimum size. 06:58: The universe will contain only photons, electrons, and black holes. 14:59: That's the classical theory, which is wrong-- and also suggested that electrons should spin faster than light. 15:11: So QED is, if not gospel truth, the most right thing we have for describing electrons." OK, nice knowledge bomb there, Gareth Dean. 15:20: Epsilon Jay asks why electrons are thought of as infinitesimal points. 16:12: But really, in principle, there's no minimum precision with which we can know the electron's location, so there's no minimum size.
	2018-08-15: Quantum Theory's Most Incredible Prediction 01:13: ... with charged particles to give us the electromagnetic force, which binds electrons to atoms, atoms to molecules, and therefore, you know, allows you to ... 01:53: ... in simple English, measuring the anomalous magnetic dipole moment of the electron. ... 03:21: It mostly comes from the summed dipole magnetic fields of individual electrons in the outer shells of its atoms. 03:29: And those electron dipole fields are, indeed, very weird. 03:41: ... if you think of them as tiny balls of rotating electric charge, except electrons aren't balls and they aren't really ... 03:53: As far as we know, electrons are pointlike. 04:02: Nonetheless, electrons do have a sort of intrinsic, angular momentum, a fundamental quantum spin that is as intrinsic as mass and charge. 04:12: Despite not being the same as classical rotation, this quantum spin does grant electrons a dipole magnetic field. 04:20: So electrons have a magnetic dipole moment, meaning they feel magnetic fields and act as little bar magnets. 04:27: Electrons in atoms feel the magnetic fields produced by their own orbits around the atom. 04:33: ... results in a subtle torque on these electrons, changing their energy states, and resulting in the fine structure ... 04:49: Thinking of electrons as little bar magnets or as rotating balls of charge is a nice starting point. 04:57: It also gives you completely the wrong answer if you try to calculate the electron's magnetic moment. 05:02: So that electron diagram you did in middle school, it's time to kill that idea just like you kill your tamagotchi. 05:09: ... fact, weirdly, if you measure the magnetic dipole moment of an electron, you get almost exactly twice the value you'd expect for a tiny classical ... 05:23: This difference between the quantum versus classical magnetic moments for the electron is called the G factor. 05:49: It describes electrons as weird, four component objects with quantum spin magnitudes of half. 06:09: ... even though the Dirac equation tells us how a relativistic electron would interact with an electromagnetic field, it still treats this EM ... 06:45: This messiness messes with the interaction of the electron and the magnetic field to shift the G factor slightly. 08:30: A basic interaction of an electron with an EM field is illustrated by this partial Feynman diagram. 08:36: An electron encounters a real photon that could represent an external magnetic field. 08:47: The electron first emits a virtual photon, then gets deflected, then re-absorbs the virtual photon. 08:54: ... in and out, so it leads to the same overall result. But now the electron undergoes an additional interaction with the buzzing quantum ... 09:04: ... secondary interaction when we calculate, say, the overall strength of an electron's interaction with the magnetic field when we calculate the electrons ... 09:50: ... there really are infinite ways the electron can interact with the EM field, with crazy networks of virtual particles ... 10:45: One way to do it is to watch the way electrons process in the constant magnetic field of a cyclotron, a type of particle accelerator. 10:54: Electron spin axes are always slightly misaligned with an external magnetic field, due to quantum uncertainty in the spin direction. 11:09: And the rate of this precession tells us the electron G factor. 11:41: So it's really the relationship between the electron magnetic moment and the fine structure constant that we're verifying. 13:21: Emma [INAUDIBLE] asks about how satellites and service electronics could be protected given advanced knowledge of a Carrington-like geomagnetic storm. 14:01: Their electronics can withstand smaller currents. 05:02: So that electron diagram you did in middle school, it's time to kill that idea just like you kill your tamagotchi. 03:29: And those electron dipole fields are, indeed, very weird. 08:36: An electron encounters a real photon that could represent an external magnetic field. 04:33: ... their energy states, and resulting in the fine structure splitting of electron energy ... 11:41: So it's really the relationship between the electron magnetic moment and the fine structure constant that we're verifying. 10:54: Electron spin axes are always slightly misaligned with an external magnetic field, due to quantum uncertainty in the spin direction. 08:54: ... in and out, so it leads to the same overall result. But now the electron undergoes an additional interaction with the buzzing quantum ... 13:21: Emma [INAUDIBLE] asks about how satellites and service electronics could be protected given advanced knowledge of a Carrington-like geomagnetic storm. 14:01: Their electronics can withstand smaller currents. 01:13: ... with charged particles to give us the electromagnetic force, which binds electrons to atoms, atoms to molecules, and therefore, you know, allows you to ... 03:21: It mostly comes from the summed dipole magnetic fields of individual electrons in the outer shells of its atoms. 03:41: ... if you think of them as tiny balls of rotating electric charge, except electrons aren't balls and they aren't really ... 03:53: As far as we know, electrons are pointlike. 04:02: Nonetheless, electrons do have a sort of intrinsic, angular momentum, a fundamental quantum spin that is as intrinsic as mass and charge. 04:12: Despite not being the same as classical rotation, this quantum spin does grant electrons a dipole magnetic field. 04:20: So electrons have a magnetic dipole moment, meaning they feel magnetic fields and act as little bar magnets. 04:27: Electrons in atoms feel the magnetic fields produced by their own orbits around the atom. 04:33: ... results in a subtle torque on these electrons, changing their energy states, and resulting in the fine structure ... 04:49: Thinking of electrons as little bar magnets or as rotating balls of charge is a nice starting point. 04:57: It also gives you completely the wrong answer if you try to calculate the electron's magnetic moment. 05:49: It describes electrons as weird, four component objects with quantum spin magnitudes of half. 09:04: ... secondary interaction when we calculate, say, the overall strength of an electron's interaction with the magnetic field when we calculate the electrons ... 10:45: One way to do it is to watch the way electrons process in the constant magnetic field of a cyclotron, a type of particle accelerator. 04:33: ... results in a subtle torque on these electrons, changing their energy states, and resulting in the fine structure splitting of ... 09:04: ... secondary interaction when we calculate, say, the overall strength of an electron's interaction with the magnetic field when we calculate the electrons magnetic dipole ... 04:57: It also gives you completely the wrong answer if you try to calculate the electron's magnetic moment. 09:04: ... an electron's interaction with the magnetic field when we calculate the electrons magnetic dipole moment and it's G ... 04:57: It also gives you completely the wrong answer if you try to calculate the electron's magnetic moment. 10:45: One way to do it is to watch the way electrons process in the constant magnetic field of a cyclotron, a type of particle accelerator.
	2018-08-01: How Close To The Sun Can Humanity Get? 04:00: It will also measure the outward flow of the magnetic field through the pointing flux, as well as the plasma density and electron temperature. 04:18: The solar wind electrons, alphas, and protons instrument-- or SWEAP-- will directly detect the particles that make up most of the solar wind. 04:27: The most common types are electrons, helium ions, AKA alpha particles, and protons. 04:51: ... the most energetic particles of the solar wind-- charged particles like electrons, protons, and heavier nuclei, measuring their energies and mapping them ... 04:00: It will also measure the outward flow of the magnetic field through the pointing flux, as well as the plasma density and electron temperature. 04:18: The solar wind electrons, alphas, and protons instrument-- or SWEAP-- will directly detect the particles that make up most of the solar wind. 04:27: The most common types are electrons, helium ions, AKA alpha particles, and protons. 04:51: ... the most energetic particles of the solar wind-- charged particles like electrons, protons, and heavier nuclei, measuring their energies and mapping them ... 04:18: The solar wind electrons, alphas, and protons instrument-- or SWEAP-- will directly detect the particles that make up most of the solar wind. 04:27: The most common types are electrons, helium ions, AKA alpha particles, and protons. 04:51: ... the most energetic particles of the solar wind-- charged particles like electrons, protons, and heavier nuclei, measuring their energies and mapping them back to ...
	2018-07-04: Will A New Neutrino Change The Standard Model? 02:46: And then there are the leptons, the ubiquitous electron and its heavier cousins, the muon and tauon, and again, each with its antimatter counterpart. 03:20: So an electron has a charge of negative 1 and an antielectron has a charge of plus 1. 04:42: ... we saw in our episode on the Higgs mechanism, real quarks and electrons are actually a combination of left and right chiral particles that ... 05:05: ... example, both left and right chiral negatively charged electrons have their own positively charged antimatter particles, which are right ... 05:26: The left chiral electron feels this force and the right chiral electron does not. 06:15: If neutrinos gained their mass by the same mechanism as quarks and electrons, that means their chirality oscillates. 06:36: Electron neutrinos can become muon neutrinos can become tau neutrinos. 07:33: Instead, MiniBooNE detected way more electron neutrinos than expected. 07:38: So I told you that neutrinos oscillate between type-- electron, muon, tau. 07:44: So the MiniBooNE experiment starts with muon neutrinos, and some of these transform into electron neutrinos by the time they hit the vat. 07:59: A lot more muon neutrinos made the transition to electron neutrino than was expected according to the basic standard model. 08:14: If muon neutrinos can flip their chirality and become sterile neutrinos, then it's an easier transition from sterile neutrino to electron neutrino. 08:27: The team finds an overabundance in electron neutrinos at the 4.8 sigma level. 08:45: That was the Liquid Scintillator Neutrino Detector, LSND, experiment at Los Alamos, which in 2001 published a 3.8-sigma excess in electron neutrinos. 09:38: ... of the existence of sterile neutrinos based on the transition of muon to electron neutrinos as they travel through the body of the ... 05:26: The left chiral electron feels this force and the right chiral electron does not. 07:38: So I told you that neutrinos oscillate between type-- electron, muon, tau. 07:59: A lot more muon neutrinos made the transition to electron neutrino than was expected according to the basic standard model. 08:14: If muon neutrinos can flip their chirality and become sterile neutrinos, then it's an easier transition from sterile neutrino to electron neutrino. 06:36: Electron neutrinos can become muon neutrinos can become tau neutrinos. 07:33: Instead, MiniBooNE detected way more electron neutrinos than expected. 07:44: So the MiniBooNE experiment starts with muon neutrinos, and some of these transform into electron neutrinos by the time they hit the vat. 08:27: The team finds an overabundance in electron neutrinos at the 4.8 sigma level. 08:45: That was the Liquid Scintillator Neutrino Detector, LSND, experiment at Los Alamos, which in 2001 published a 3.8-sigma excess in electron neutrinos. 09:38: ... of the existence of sterile neutrinos based on the transition of muon to electron neutrinos as they travel through the body of the ... 01:52: ... as reported in the 2018 paper, "Observation of a Significant Excess of Electron-like Events in the MiniBooNE Short Baseline Neutrino Experiment." Catchy ... 04:42: ... we saw in our episode on the Higgs mechanism, real quarks and electrons are actually a combination of left and right chiral particles that ... 05:05: ... example, both left and right chiral negatively charged electrons have their own positively charged antimatter particles, which are right ... 06:15: If neutrinos gained their mass by the same mechanism as quarks and electrons, that means their chirality oscillates. 09:17: It would have a relatively low mass at around 1 electronvolt.
	2018-06-27: How Asteroid Mining Will Save Earth 05:22: ... groups are essential in everything from electronic components, batteries and fuel cells, magnets, as chemical catalysts and ...
	2018-06-20: The Black Hole Information Paradox 12:52: EpsilonJ asked, what would happen if you fired a continuous beam of electrons at a black hole and how would the charge affect the Penrose diagram?
	2018-06-13: What Survives Inside A Black Hole? 00:09: A proton, an electron, and an antineutrino walk into a black hole. 11:57: How is probability conserved when an electron and a positron annihilate each other? 12:39: In the specific case of electron-positron annihilation, information continues to exist after the event in the products of that annihilation.
	2018-05-23: Why Quantum Information is Never Destroyed 05:36: ... wave function in a given potential could mean the wave function of an electron moving in an atom's electric field, or it could mean the wave function ...
	2018-05-02: The Star at the End of Time 06:00: ... contract into a helium white dwarf, supported by quantum mechanical electron degeneracy ...
	2018-03-21: Scientists Have Detected the First Stars 01:31: ... of photon-- the one that is released or absorbed, when the ground state electron and hydrogen flips its spin ... 01:57: We say that the electron spin temperature was coupled to the CMB temperature. 02:20: ... ultraviolet light from those stars shifted the equilibrium so that the electron spin temperature became connected to the temperature of the gas, instead ... 01:57: We say that the electron spin temperature was coupled to the CMB temperature. 02:20: ... ultraviolet light from those stars shifted the equilibrium so that the electron spin temperature became connected to the temperature of the gas, instead of ... 01:57: We say that the electron spin temperature was coupled to the CMB temperature. 02:20: ... ultraviolet light from those stars shifted the equilibrium so that the electron spin temperature became connected to the temperature of the gas, instead of the ...
	2018-03-07: Should Space be Privatized? 11:42: When fusion switches off, the star contracts, until electron degeneracy pressure stops the collapse.
	2018-02-21: The Death of the Sun 04:00: The electrons are packed so close together that they become degenerate. 04:08: ... the Pauli exclusion principle, the rule that says is that fermions, like electrons, can't occupy the same quantum state as each ... 04:00: The electrons are packed so close together that they become degenerate. 04:08: ... the Pauli exclusion principle, the rule that says is that fermions, like electrons, can't occupy the same quantum state as each ...
	2018-01-31: Kronos: Devourer Of Worlds 03:49: Stellar spectra are thick, with sharp emission and absorption features that result from electron transitions in atoms in the star's atmosphere.
	2018-01-17: Horizon Radiation 03:08: Imagine I fire a pair of photons, which annihilate to produce an electron, positron pair. 03:14: ... agree on the basic result of that interaction-- two photons in, one electron, one positron ... 08:28: ... a particle interaction like those two photons annihilating into an electron, positron ... 03:08: Imagine I fire a pair of photons, which annihilate to produce an electron, positron pair. 08:28: ... a particle interaction like those two photons annihilating into an electron, positron ... 03:08: Imagine I fire a pair of photons, which annihilate to produce an electron, positron pair. 08:28: ... a particle interaction like those two photons annihilating into an electron, positron pair. ...
	2018-01-10: What Do Stars Sound Like? 12:39: In fact, the magnetic field of a gamma ray burst focuses charged particles-- electrons and the nuclei of the exploding star. 13:29: Upcycle Electronics suggests that I stole the Ordovician Silurian extinction script from PBS Eons. 12:39: In fact, the magnetic field of a gamma ray burst focuses charged particles-- electrons and the nuclei of the exploding star.
	2017-11-02: The Vacuum Catastrophe 03:12: It's where photon energy is equal to the Planck energy, or 10 to the power of 19 giga electron volts.
	2017-10-25: The Missing Mass Mystery 05:59: Well, our best guess is that it's in the form of a very diffuse plasma, atoms stripped of their electrons in between the galaxies. 06:25: On the other hand, if the material is cool enough, then nuclei can recapture their electrons and become a gas instead of a plasma. 08:41: In fact, the electrons in that plasma scatter CMB photons to higher energies. 05:59: Well, our best guess is that it's in the form of a very diffuse plasma, atoms stripped of their electrons in between the galaxies. 06:25: On the other hand, if the material is cool enough, then nuclei can recapture their electrons and become a gas instead of a plasma. 08:41: In fact, the electrons in that plasma scatter CMB photons to higher energies.
	2017-10-19: The Nature of Nothing 02:15: ... vibrate with different energies, and those oscillations are the electrons, quarks, neutrinos, photons, gluons, et cetera, that comprise the stuff ... 02:41: In each quantum state, so each combination of particle properties, there is a ladder of energy levels, a bit like electron orbitals in an atom. 07:10: ... and Robert Rutherford noticed a tiny energy difference between the two electron orbitals that comprise the second energy level of the hydrogen ... 07:58: ... partially shields the orbiting electrons from the positive charge of the nucleus, with the amount of shielding ... 09:57: They just measure its relative effect, inside versus outside Casimir plates, or between electrons in neighboring orbits. 13:32: ... the elementary particles that form atoms are all spin-half fermions, so electrons and quarks, while the force-carrying particles like photons, gluons, et ... 13:53: But in a helium-4 nucleus, the protons pair up and have opposite spins, so they cancel out, same with the neutrons and the electrons. 02:41: In each quantum state, so each combination of particle properties, there is a ladder of energy levels, a bit like electron orbitals in an atom. 07:10: ... and Robert Rutherford noticed a tiny energy difference between the two electron orbitals that comprise the second energy level of the hydrogen ... 02:15: ... vibrate with different energies, and those oscillations are the electrons, quarks, neutrinos, photons, gluons, et cetera, that comprise the stuff ... 07:58: ... partially shields the orbiting electrons from the positive charge of the nucleus, with the amount of shielding ... 09:57: They just measure its relative effect, inside versus outside Casimir plates, or between electrons in neighboring orbits. 13:32: ... the elementary particles that form atoms are all spin-half fermions, so electrons and quarks, while the force-carrying particles like photons, gluons, et ... 13:53: But in a helium-4 nucleus, the protons pair up and have opposite spins, so they cancel out, same with the neutrons and the electrons. 02:15: ... vibrate with different energies, and those oscillations are the electrons, quarks, neutrinos, photons, gluons, et cetera, that comprise the stuff of our ...
	2017-10-11: Absolute Cold 01:37: You get more heat causes electrons than any gas to escape the bonds of their atoms, resulting in the less known plasma state. 02:07: They can only occupy certain energy levels of vibration or motion, much like the discrete electron orbitals in an atom. 03:18: In certain solids, bonded pairs of electrons-- Cooper pairs-- condense into this state. 02:07: They can only occupy certain energy levels of vibration or motion, much like the discrete electron orbitals in an atom. 01:37: You get more heat causes electrons than any gas to escape the bonds of their atoms, resulting in the less known plasma state. 03:18: In certain solids, bonded pairs of electrons-- Cooper pairs-- condense into this state.
	2017-10-04: When Quasars Collide STJC 05:15: The radio light seen here is from electrons spiraling in those magnetic fields, so-called synchrotron radiation. 06:14: Spiraling electrons produce radio waves a lots of frequencies all the way down to very low energies. 05:15: The radio light seen here is from electrons spiraling in those magnetic fields, so-called synchrotron radiation. 06:14: Spiraling electrons produce radio waves a lots of frequencies all the way down to very low energies. 05:15: The radio light seen here is from electrons spiraling in those magnetic fields, so-called synchrotron radiation.
	2017-09-28: Are the Fundamental Constants Changing? 01:00: ... be predicted by that model, only measured-- things like the mass of the electron and the relative strengths of the forces of ... 03:11: The dimensions behind, say, Newton's gravitational constant-- or the mass of the electron-- all have arbitrary human definitions. 03:42: In the language of quantum field theory, it's the coupling strength between the electromagnetic field and a charged field like the electron field. 04:34: Electron energy levels-- or orbitals in atoms-- are quantized, meaning only certain levels are allowed. 04:41: When electrons move between levels, they emit or absorb photons with energies equal to that lost or gained by the electron. 05:08: This splitting is due to the fact that each atomic energy level can host two electrons. 05:13: And these electrons have spins pointing in opposite directions. 05:17: Now, quantum spin gives electrons what we call a magnetic moment. 05:31: These same electrons are also orbiting the atomic nucleus, and that motion generates its own magnetic field. 05:38: ... magnetic fields produced by an electron's spin and by its orbital motion actually interact with each other in an ... 06:02: So when electrons jump between orbitals, the energy they absorb or emit depends on their spin alignment. 10:38: ... into the variation of other dimensionless constants, such as the proton electron mass ratio, and the more obscure proton gyromagnetic ... 04:34: Electron energy levels-- or orbitals in atoms-- are quantized, meaning only certain levels are allowed. 03:42: In the language of quantum field theory, it's the coupling strength between the electromagnetic field and a charged field like the electron field. 10:38: ... into the variation of other dimensionless constants, such as the proton electron mass ratio, and the more obscure proton gyromagnetic ... 04:41: When electrons move between levels, they emit or absorb photons with energies equal to that lost or gained by the electron. 05:08: This splitting is due to the fact that each atomic energy level can host two electrons. 05:13: And these electrons have spins pointing in opposite directions. 05:17: Now, quantum spin gives electrons what we call a magnetic moment. 05:31: These same electrons are also orbiting the atomic nucleus, and that motion generates its own magnetic field. 05:38: ... magnetic fields produced by an electron's spin and by its orbital motion actually interact with each other in an ... 06:02: So when electrons jump between orbitals, the energy they absorb or emit depends on their spin alignment. 05:38: ... magnetic fields produced by an electron's spin and by its orbital motion actually interact with each other in an effect ...
	2017-09-20: The Future of Space Telescopes 12:04: The final phase of the core of such a star is a giant ball of nickel and iron, held up briefly by electron degeneracy pressure. 12:14: Basically, the electrons are crammed as close together as quantum mechanics allows. 12:18: That support gives way when pressure rams electrons into protons in the nuclei to turn them into neutrons. 12:04: The final phase of the core of such a star is a giant ball of nickel and iron, held up briefly by electron degeneracy pressure. 12:14: Basically, the electrons are crammed as close together as quantum mechanics allows. 12:18: That support gives way when pressure rams electrons into protons in the nuclei to turn them into neutrons.
	2017-08-16: Extraterrestrial Superstorms 11:50: Last week, we talked about John Archibald Wheeler's one electron universe idea as well as gave the solution to the Feynman diagram challenge. 12:07: Well, Wheeler was really just using the electron as an example. 12:31: Well, actually, the fun thing about the one electron proposition is that it doesn't matter when in time you are. 12:48: Now, draw the zigzag of an electron bouncing up and down. 13:02: Count each upward-moving line as an electron and the downs as positrons. 13:09: You'll always get the same number of electrons versus positrons. 12:48: Now, draw the zigzag of an electron bouncing up and down. 12:31: Well, actually, the fun thing about the one electron proposition is that it doesn't matter when in time you are. 11:50: Last week, we talked about John Archibald Wheeler's one electron universe idea as well as gave the solution to the Feynman diagram challenge. 13:09: You'll always get the same number of electrons versus positrons.
	2017-08-10: The One-Electron Universe 00:01: ... lead to the most profound advances-- for example, the idea that every electron in the universe is really the one same electron traveling forwards and ... 00:33: The fateful conversation began, Feynman, I know why all electrons have the same charge and the same mass. 00:45: Because they are all the same electron. 00:51: Wheeler went on to describe his one-electron universe idea-- that there exists only one electron. 00:58: And that electron traverses time in both directions. 01:12: In this way, it fills the universe with the appearance of countless electrons. 01:17: When the electron is moving backwards in time, it's a positron, the anti-matter counterpart of the electron. 02:04: ... one-electron universe was motivated by an odd fact about electrons that had troubled Wheeler-- that they are all identical, exactly the ... 02:20: Wheeler's notion was that if electrons behave as though they are identical, perhaps they truly are, to the point of being identically the same entity. 02:31: Let's think about the electron as its worldline. 02:41: The point-like electron is just a segment of that worldline if we take a slice through space time at one instant in time. 02:50: The direction of an electron's worldline can shift as the electron is scattered by photons. 02:56: But what if it were possible to deflect an electron back the way it came temporally? 03:03: If an electron can reverse its course in time, then its worldline looks like a zigzag. 03:09: At any one point, there can be multiple instances of the same electron. 03:25: That one electron zigzagging back and forth 10 to the power of 80 times looks like all of the electrons in the universe. 03:58: ... example, if a negatively charged electron is moving to the left, it produces some current, I. Then, an electron ... 04:24: ... same flipped sign whether you reverse the direction of the motion of the electron, or if you give it the opposite charge by turning it into a ... 06:34: ... example, this one diagram for electron and photon scattering represents both the double deflection of an ... 06:49: That virtual particle in the middle may be an electron traveling forwards or backwards in time. 07:03: We can think of the annihilation of an electron and positron as just the electron being deflected back in time. 07:11: Similarly, the creation of a particle pair is the electron being scattered in time. 07:18: ... we draw a Feynman diagram for the whole universe, we can have only one electron undergo countless scattering events, some of which change its course ... 07:30: At some point in the middle of the diagram, we see many, many electrons. 07:35: Wheeler's idea was that they are the same electron. 07:44: The biggest is that we should see equal numbers of electrons and positrons at any time. 07:50: After all, when that first electron makes it to the end of time, it needs to travel back again as a positron in order to have any more electrons. 07:59: But clearly, there are more forward propagating electrons than positrons. 08:15: It's certainly not widely accepted that there's only one electron in this universe, nor whether that's even a meaningful statement. 08:23: We now think of electrons as oscillations, as waves, in the more fundamental electron field. 08:29: It doesn't really make sense to think of an electron as a thing that carries an identifying label. 08:45: ... that every electron-- indeed every particle in our bodies, in everyone's bodies-- is the same ... 09:22: ... all of the two-vertex and four-vertex diagrams for the interaction where electrons and positrons scatter off each other using the simple rules I laid out ... 09:44: ... one case, we have a positron and an electron influencing each other's momentum by exchanging a virtual photon-- ... 09:53: ... in the second case, the electron and positron actually annihilate each other, producing a virtual photon, ... 08:23: We now think of electrons as oscillations, as waves, in the more fundamental electron field. 09:44: ... one case, we have a positron and an electron influencing each other's momentum by exchanging a virtual photon-- similar to ... 03:58: ... electron is moving to the left, it produces some current, I. Then, an electron moving to the right produces the same strength of current, but with the ... 00:01: ... the idea that every electron in the universe is really the one same electron traveling forwards and backwards in ... 06:49: That virtual particle in the middle may be an electron traveling forwards or backwards in time. 00:01: ... the idea that every electron in the universe is really the one same electron traveling forwards and backwards in ... 06:49: That virtual particle in the middle may be an electron traveling forwards or backwards in time. 00:58: And that electron traverses time in both directions. 07:18: ... we draw a Feynman diagram for the whole universe, we can have only one electron undergo countless scattering events, some of which change its course through ... 03:25: That one electron zigzagging back and forth 10 to the power of 80 times looks like all of the electrons in the universe. 09:44: ... each other's momentum by exchanging a virtual photon-- similar to electron-electron ... 06:34: ... both the double deflection of an electron or of a photon producing an electron-positron pair before the positron annihilates with the first ... 09:53: ... each other, producing a virtual photon, which then creates a new electron-positron ... 06:34: ... both the double deflection of an electron or of a photon producing an electron-positron pair before the positron annihilates with the first ... 09:53: ... each other, producing a virtual photon, which then creates a new electron-positron pair. ... 00:33: The fateful conversation began, Feynman, I know why all electrons have the same charge and the same mass. 01:12: In this way, it fills the universe with the appearance of countless electrons. 02:04: ... one-electron universe was motivated by an odd fact about electrons that had troubled Wheeler-- that they are all identical, exactly the ... 02:20: Wheeler's notion was that if electrons behave as though they are identical, perhaps they truly are, to the point of being identically the same entity. 02:50: The direction of an electron's worldline can shift as the electron is scattered by photons. 03:25: That one electron zigzagging back and forth 10 to the power of 80 times looks like all of the electrons in the universe. 07:30: At some point in the middle of the diagram, we see many, many electrons. 07:44: The biggest is that we should see equal numbers of electrons and positrons at any time. 07:50: After all, when that first electron makes it to the end of time, it needs to travel back again as a positron in order to have any more electrons. 07:59: But clearly, there are more forward propagating electrons than positrons. 08:23: We now think of electrons as oscillations, as waves, in the more fundamental electron field. 09:22: ... all of the two-vertex and four-vertex diagrams for the interaction where electrons and positrons scatter off each other using the simple rules I laid out ... 02:20: Wheeler's notion was that if electrons behave as though they are identical, perhaps they truly are, to the point of being identically the same entity. 02:50: The direction of an electron's worldline can shift as the electron is scattered by photons.
	2017-08-02: Dark Flow 10:04: ... that the Feynman diagram vertex, representing interactions between an electron, positron, and photon, is not by itself a valid ... 10:35: For example, in order to conserve momentum, an annihilating electron and positron must produce two photons, not one. 10:43: ... Bender asks whether electrons and positrons in Bhabha scattering have to remain on their respective ... 11:19: JoJoMorning asks, what if one incoming electron is entangled to another electron? 11:27: The answer is that the states of the outgoing particles are also entangled with that other electron. 11:41: ... the case of single entanglement, say, of two electrons, measurement of the properties of one of the electrons appears to ... 11:57: ... if that measurement instead happens after the electron undergoes an interaction, represented by a Feynman diagram, then we need ... 10:04: ... that the Feynman diagram vertex, representing interactions between an electron, positron, and photon, is not by itself a valid ... 11:57: ... if that measurement instead happens after the electron undergoes an interaction, represented by a Feynman diagram, then we need to think ... 10:43: ... Bender asks whether electrons and positrons in Bhabha scattering have to remain on their respective ... 11:41: ... the case of single entanglement, say, of two electrons, measurement of the properties of one of the electrons appears to ...
	2017-07-26: The Secrets of Feynman Diagrams 02:02: The first and most predictively powerful quantum field theory, QED, talks about the interaction of the electron field with the electromagnetic field. 02:12: That means interactions between electrons; their anti-matter counterparts, the positron; and photons. 02:19: In Feynman diagrams, we depict the electron as an arrow pointing forwards in time, while the positron is an arrow pointing backwards in time. 03:31: ... this with time increasing upwards, this vertex represents an initial electron that emits a photon, after which, both particles move off in opposite ... 03:42: But if we rotate this vertex so that photon is coming in from below, we have a picture in which an electron absorbs that incoming photon. 03:52: The photon vanishes as its momentum is completely transferred to the electron. 04:07: ... absorbing a photon, and a positron emitting photon, and finally, an electron and a positron annihilating each other to produce a ... 04:24: That's all the ways that the electromagnetic and electron fields can interact. 04:50: If one electron positron goes in, then one electron or positron, respectively, must leave. 04:56: If an electron and positron both go in, then their charges cancel. 05:04: Similarly, if a photon creates a negatively charged electron, it must also create a positively charged positron. 06:56: Electron scattering can be depicted as two electrons going into an interaction and then two electrons going out. 07:02: We know the momentum of the ingoing and outgoing electrons. 07:13: Simple examples are the exchange of a single photon to transfer momentum between electrons, or the exchange of two or more photons. 07:21: ... we can add as many of these vertices as we like, including the electrons exchanging photons with themselves at different stages in the process, ... 08:16: ... example, for two electrons exchanging a single photon, it doesn't matter if we draw the photon ... 08:45: An incoming electron and an incoming photon bounce off each other. 08:49: One way that can happen is for the electron to emit a new photon and later absorb the old incoming photon. 08:56: ... that intermediate stage between vertices, the electron is a virtual particle, which means we include all possible paths it ... 09:12: Mathematically, a time-reversed electron looks exactly like a positron-- like this. 09:25: Instead of an electron emitting and absorbing a photon, we have on one side that incoming photon creating an electron-positron pair. 09:34: That new electron becomes our outgoing electron. 09:37: But the positron annihilates with the incoming electron to produce the outgoing photon. 10:34: When an electron and a positron interact electromagnetically, we call it Bhabha scattering. 11:12: For the latter, don't bother with what we call the self-energy diagrams, in which electrons or positrons emit and then reabsorb a photon. 03:42: But if we rotate this vertex so that photon is coming in from below, we have a picture in which an electron absorbs that incoming photon. 09:25: Instead of an electron emitting and absorbing a photon, we have on one side that incoming photon creating an electron-positron pair. 02:02: The first and most predictively powerful quantum field theory, QED, talks about the interaction of the electron field with the electromagnetic field. 04:24: That's all the ways that the electromagnetic and electron fields can interact. 04:50: If one electron positron goes in, then one electron or positron, respectively, must leave. 06:56: Electron scattering can be depicted as two electrons going into an interaction and then two electrons going out. 03:56: ... picture is of a photon coming in and giving up its energy to produce an electron-positron pair, a process we call pair ... 07:21: ... stages in the process, or photons momentarily splitting into virtual electron-positron ... 09:25: Instead of an electron emitting and absorbing a photon, we have on one side that incoming photon creating an electron-positron pair. 03:56: ... picture is of a photon coming in and giving up its energy to produce an electron-positron pair, a process we call pair ... 09:25: Instead of an electron emitting and absorbing a photon, we have on one side that incoming photon creating an electron-positron pair. 07:21: ... stages in the process, or photons momentarily splitting into virtual electron-positron pairs. ... 02:12: That means interactions between electrons; their anti-matter counterparts, the positron; and photons. 06:56: Electron scattering can be depicted as two electrons going into an interaction and then two electrons going out. 07:02: We know the momentum of the ingoing and outgoing electrons. 07:13: Simple examples are the exchange of a single photon to transfer momentum between electrons, or the exchange of two or more photons. 07:21: ... we can add as many of these vertices as we like, including the electrons exchanging photons with themselves at different stages in the process, ... 08:16: ... example, for two electrons exchanging a single photon, it doesn't matter if we draw the photon ... 11:12: For the latter, don't bother with what we call the self-energy diagrams, in which electrons or positrons emit and then reabsorb a photon. 07:21: ... we can add as many of these vertices as we like, including the electrons exchanging photons with themselves at different stages in the process, or photons ... 08:16: ... example, for two electrons exchanging a single photon, it doesn't matter if we draw the photon going from the ... 07:21: ... we can add as many of these vertices as we like, including the electrons exchanging photons with themselves at different stages in the process, or photons ...
	2017-07-19: The Real Star Wars 04:51: They work by exciting electrons in a substance to high-energy states. 05:05: The excited electron releases its energy is a photon that exactly matches the phase and direction of the seed photon. 14:51: ... noticed that the theoretical electron mass going to infinity sounds a lot like the ultraviolet catastrophe of ... 15:20: Nicholas Aiello asks if it's possible that electrons have no fundamental mass and are made up entirely of self energy. 15:30: The so-called bare mass of an electron comes from its interaction with the Higgs field. 15:36: ... in some ways the Higgs field exchange is weak hypercharged with the electron via W bosons, causing its [INAUDIBLE] to ... 15:56: ... Electron mass comes from its interaction with other fields, be it the Higgs field ... 16:07: ... Crawford asks, how do we know that two electrons scatter off each other, rather than just pass through each other, given ... 16:17: In fact, we have no idea which outgoing electron corresponds to which incoming electron. 16:24: All we know is the momenta of all of those electrons. 16:27: When we draw the Feynman diagrams for electron scattering, we need to include separate diagrams in which the ingoing electrons swap places. 16:51: Every one of those vertices represents an interaction between the electron and the electromagnetic fields. 17:28: ... every additional interaction between the EM and the electron field, so every additional vertex, another one of these 1% probability ... 16:17: In fact, we have no idea which outgoing electron corresponds to which incoming electron. 17:28: ... every additional interaction between the EM and the electron field, so every additional vertex, another one of these 1% probability events ... 14:51: ... noticed that the theoretical electron mass going to infinity sounds a lot like the ultraviolet catastrophe of the ... 15:56: ... Electron mass comes from its interaction with other fields, be it the Higgs field for ... 05:05: The excited electron releases its energy is a photon that exactly matches the phase and direction of the seed photon. 16:27: When we draw the Feynman diagrams for electron scattering, we need to include separate diagrams in which the ingoing electrons swap places. 04:51: They work by exciting electrons in a substance to high-energy states. 15:20: Nicholas Aiello asks if it's possible that electrons have no fundamental mass and are made up entirely of self energy. 16:07: ... Crawford asks, how do we know that two electrons scatter off each other, rather than just pass through each other, given ... 16:24: All we know is the momenta of all of those electrons. 16:27: When we draw the Feynman diagrams for electron scattering, we need to include separate diagrams in which the ingoing electrons swap places. 16:07: ... Crawford asks, how do we know that two electrons scatter off each other, rather than just pass through each other, given that ... 16:27: When we draw the Feynman diagrams for electron scattering, we need to include separate diagrams in which the ingoing electrons swap places.
	2017-07-12: Solving the Impossible in Quantum Field Theory 01:26: ... field theory can be, let's look at what should be a simple phenomenon-- electron scattering, when two electrons repel each ... 01:38: In old-fashioned classical electrodynamics, we think of each electron as producing an electromagnetic field. 01:46: That field then exerts a repulsive force on the other electron. 02:06: We think of the electromagnetic field as existing everywhere in space, whether or not there's an electron present. 02:18: The electron itself is just an excitation, a vibration in a different field-- the electron field. 02:25: And the electron and EM fields are connected. 02:32: This is how QED describes electron scattering. 02:35: One electron excites a photon, and that photon delivers a bit of the first electron's momentum to the second electron. 03:27: Here we see two electrons entering in the beginning and moving towards each other. 03:31: They exchange a virtual photon-- this squiggly line here-- and the two electrons move apart at the end. 03:50: Incoming lines are associated with the initial electron states, and outgoing lines represent the final electron states. 04:09: ... together from this one diagram represents all of the ways that two electrons can deflect involving only a single virtual ... 04:24: Unfortunately, real electron scattering at a quantum level is a good deal more complicated than this. 04:31: For that reason, this simple calculation gives the wrong repulsive effect between two electrons. 04:37: If we observe two electrons bouncing off each other, all we really see is two electrons going in and two electrons going out. 05:08: ... as with the path integral, to perfectly calculate the scattering of two electrons, we need to add up all of the ways the electrons can be ... 05:26: For example, the electrons might exchange just a single virtual photon, but they might also exchange two, or three, or more. 05:34: The electrons might also emit and reabsorb a virtual photon. 06:32: In the case of electron scattering, the most likely interaction is the exchange of a single photon. 06:38: Every other way to scatter the electrons contributes less to the probability of the event. 07:08: So the most probable interaction for electron scattering is the simple case of one photon exchange with its two vertices. 07:24: However, it turns out that for electron scattering, there are no three-vertex interactions. 07:43: ... include exchanging two virtual photons, or one electron emitting and reabsorbing a virtual photon, or the exchanged photon ... 08:21: ... pair and then reverts to a photon again, or when a single electron emits and reabsorbs the same ... 08:36: This latter case can be thought of as the electron causing a constant disturbance in EM field. 08:41: Electrons are constantly interacting with virtual photons. 08:45: This impedes the electron's motion and actually increases its effective mass. 08:54: ... if you try to calculate the self-energy correction to an electron's mass using quantum electrodynamics, you get that the electron has ... 09:44: ... electrons do not have infinite mass, and we know that because we've measured that ... 10:05: ... of trying to start with the unmeasurable fundamental mass of the electron and solve the equations from there, you fold in a term for the ... 08:36: This latter case can be thought of as the electron causing a constant disturbance in EM field. 08:21: ... pair and then reverts to a photon again, or when a single electron emits and reabsorbs the same ... 07:43: ... include exchanging two virtual photons, or one electron emitting and reabsorbing a virtual photon, or the exchanged photon momentarily ... 02:35: One electron excites a photon, and that photon delivers a bit of the first electron's momentum to the second electron. 02:18: The electron itself is just an excitation, a vibration in a different field-- the electron field. 01:26: ... field theory can be, let's look at what should be a simple phenomenon-- electron scattering, when two electrons repel each ... 02:32: This is how QED describes electron scattering. 04:24: Unfortunately, real electron scattering at a quantum level is a good deal more complicated than this. 06:32: In the case of electron scattering, the most likely interaction is the exchange of a single photon. 07:08: So the most probable interaction for electron scattering is the simple case of one photon exchange with its two vertices. 07:24: However, it turns out that for electron scattering, there are no three-vertex interactions. 03:50: Incoming lines are associated with the initial electron states, and outgoing lines represent the final electron states. 07:43: ... a virtual photon, or the exchanged photon momentarily exciting a virtual electron-positron ... 01:26: ... at what should be a simple phenomenon-- electron scattering, when two electrons repel each ... 02:35: One electron excites a photon, and that photon delivers a bit of the first electron's momentum to the second electron. 03:27: Here we see two electrons entering in the beginning and moving towards each other. 03:31: They exchange a virtual photon-- this squiggly line here-- and the two electrons move apart at the end. 04:09: ... together from this one diagram represents all of the ways that two electrons can deflect involving only a single virtual ... 04:31: For that reason, this simple calculation gives the wrong repulsive effect between two electrons. 04:37: If we observe two electrons bouncing off each other, all we really see is two electrons going in and two electrons going out. 05:08: ... as with the path integral, to perfectly calculate the scattering of two electrons, we need to add up all of the ways the electrons can be ... 05:26: For example, the electrons might exchange just a single virtual photon, but they might also exchange two, or three, or more. 05:34: The electrons might also emit and reabsorb a virtual photon. 06:38: Every other way to scatter the electrons contributes less to the probability of the event. 08:41: Electrons are constantly interacting with virtual photons. 08:45: This impedes the electron's motion and actually increases its effective mass. 08:54: ... if you try to calculate the self-energy correction to an electron's mass using quantum electrodynamics, you get that the electron has ... 09:44: ... electrons do not have infinite mass, and we know that because we've measured that ... 04:37: If we observe two electrons bouncing off each other, all we really see is two electrons going in and two electrons going out. 06:38: Every other way to scatter the electrons contributes less to the probability of the event. 03:27: Here we see two electrons entering in the beginning and moving towards each other. 08:54: ... if you try to calculate the self-energy correction to an electron's mass using quantum electrodynamics, you get that the electron has infinite ... 02:35: One electron excites a photon, and that photon delivers a bit of the first electron's momentum to the second electron. 08:45: This impedes the electron's motion and actually increases its effective mass. 01:26: ... at what should be a simple phenomenon-- electron scattering, when two electrons repel each ...
	2017-07-07: Feynman's Infinite Quantum Paths 01:10: ... for the double-slit experiment is this-- a particle, say a photon or an electron, travels through a barrier containing two slits to a ... 09:17: And a traveling electron could emit and reabsorb a photon, which itself could make its own particle-antiparticle pair ad infinitum. 10:10: ... a photon's energy moving from the electromagnetic field into, say, the electron field, where it might become an electron-positron ... 01:10: ... for the double-slit experiment is this-- a particle, say a photon or an electron, travels through a barrier containing two slits to a ... 09:07: ... photon traveling between two points could spontaneously become a virtual electron-positron pair before they annihilate back into the original ... 10:10: ... field into, say, the electron field, where it might become an electron-positron ... 09:07: ... photon traveling between two points could spontaneously become a virtual electron-positron pair before they annihilate back into the original ... 10:10: ... field into, say, the electron field, where it might become an electron-positron pair. ...
	2017-06-28: The First Quantum Field Theory 01:38: The pillars of QED are the description of the behavior of the EM field and the description of the behavior of the electron via the Dirac equation. 05:21: We also saw how Paul Dirac managed to find an equation describing the behavior of the electron that worked with relativity-- the Dirac equation. 06:08: If you take a pair of electrons or photons in two quantum states and make them swap places, then nothing changes. 09:07: An electron can absorb or emit a photon. 09:10: An electron and a positron can annihilate each other and create two photons. 09:40: ... to predict, with incredible precision, the tiny difference in atomic electron energy levels due to electron spins-- spins interacting with magnetic ... 10:26: ... exclusion principle tells you that you can only have one fermion, or electron quark, et cetera, per quantum state, rather than infinite particles in ... 11:22: There's an electron field whose oscillations are what we know as the electron and the antielectron. 14:02: ... also just didn't work for electrons because it failed to predict the fine structure emission line energies ... 09:40: ... to predict, with incredible precision, the tiny difference in atomic electron energy levels due to electron spins-- spins interacting with magnetic fields in ... 11:22: There's an electron field whose oscillations are what we know as the electron and the antielectron. 10:26: ... exclusion principle tells you that you can only have one fermion, or electron quark, et cetera, per quantum state, rather than infinite particles in the case ... 14:02: ... structure emission line energies in hydrogen due to not accounting for electron spin. ... 09:40: ... precision, the tiny difference in atomic electron energy levels due to electron spins-- spins interacting with magnetic fields in the so-called hyperfine ... 06:08: If you take a pair of electrons or photons in two quantum states and make them swap places, then nothing changes. 14:02: ... also just didn't work for electrons because it failed to predict the fine structure emission line energies ...
	2017-06-21: Anti-Matter and Quantum Relativity 02:47: For example, an electron's spin causes them to align themselves with magnetic fields, just like a rotating electric charge would. 03:06: Pauli realized that to explain electron energy levels in atoms, those electrons must obey a rule that we call the Pauli exclusion principle. 03:16: It states that no electron can occupy the same quantum state as another electron. 03:24: In the case of electrons in atoms, it suggests that we should only find one electron per atomic orbital, if we count each orbital as a quantum state. 03:34: However, we actually observe two electrons per orbital. 03:42: Pauli introduced what we call a new degree of freedom internal to electrons, one that could take on one of two values. 03:53: ... would allow two separate electrons, one up, one down, to occupy the same atomic energy level, without ... 04:31: So for fast moving electrons and for electrons in electromagnetic fields, the Schrodinger equation gives the wrong answers. 04:45: He wanted a fully relativistic version of the Schrodinger equation that worked for electrons. 05:20: That simplification required Dirac to expand the internal workings of the electron even further. 06:02: The Dirac equation perfectly predicts the motion of electrons at any speed, even in an electromagnetic field. 06:15: To begin with, what on earth were those two extra degrees of freedom in the four-component electron? 06:22: The answer came from trying to calculate the energy of the electron using this equation. 06:30: It allowed electrons to exist in states of negative energy. 06:38: ... example, a lone electron moving in an electromagnetic field could keep releasing energy as light ... 07:00: Imagine an infinitely deep ocean of electrons that exists everywhere in the universe. 07:06: These electrons occupy all of the negative energy states, all the way from negative infinity, up to zero. 07:14: The only time we can actually interact with an electron is when one has a positive energy, which would leave it sitting on top of the sea. 07:26: If the energy states of this imaginary ocean are all completely full, then that one extra electron can't lose any more energy. 07:41: Remove one electron from the surface and it leaves a hole. 07:52: It would have inertia, acting like it had the mass of the missing electron. 07:57: It would also act like it had the opposite electric charge to the electron, a positive charge. 08:03: ... if a positive energy electron found one of these holes, it would fall in, annihilating both, and ... 09:19: Only a few years after Dirac wrote down his equation in 1928, the positron, the anti-matter electron, was spotted in cosmic rays by Carl Anderson. 09:39: Anti-matter's existence is fundamentally tied to these weird four-component electrons that Dirac invented to make his equation work. 09:48: ... two extra components correspond to the up and down spins of the electron's anti-matter counterpart, two spin directions for the electron, two for ... 10:02: In fact, the electron and the positron cannot exist without each other. 10:06: They are two sides of the same coin, positive and negative energy solutions of the same type of vibration in the electron field. 03:06: Pauli realized that to explain electron energy levels in atoms, those electrons must obey a rule that we call the Pauli exclusion principle. 10:06: They are two sides of the same coin, positive and negative energy solutions of the same type of vibration in the electron field. 06:38: ... example, a lone electron moving in an electromagnetic field could keep releasing energy as light ... 02:47: For example, an electron's spin causes them to align themselves with magnetic fields, just like a rotating electric charge would. 03:06: Pauli realized that to explain electron energy levels in atoms, those electrons must obey a rule that we call the Pauli exclusion principle. 03:24: In the case of electrons in atoms, it suggests that we should only find one electron per atomic orbital, if we count each orbital as a quantum state. 03:34: However, we actually observe two electrons per orbital. 03:42: Pauli introduced what we call a new degree of freedom internal to electrons, one that could take on one of two values. 03:53: ... would allow two separate electrons, one up, one down, to occupy the same atomic energy level, without ... 04:31: So for fast moving electrons and for electrons in electromagnetic fields, the Schrodinger equation gives the wrong answers. 04:45: He wanted a fully relativistic version of the Schrodinger equation that worked for electrons. 06:02: The Dirac equation perfectly predicts the motion of electrons at any speed, even in an electromagnetic field. 06:30: It allowed electrons to exist in states of negative energy. 07:00: Imagine an infinitely deep ocean of electrons that exists everywhere in the universe. 07:06: These electrons occupy all of the negative energy states, all the way from negative infinity, up to zero. 09:39: Anti-matter's existence is fundamentally tied to these weird four-component electrons that Dirac invented to make his equation work. 09:48: ... two extra components correspond to the up and down spins of the electron's anti-matter counterpart, two spin directions for the electron, two for ... 07:06: These electrons occupy all of the negative energy states, all the way from negative infinity, up to zero. 02:47: For example, an electron's spin causes them to align themselves with magnetic fields, just like a rotating electric charge would.
	2017-05-31: The Fate of the First Stars 06:22: As these metals get jostled in a warm cloud, their electrons absorb energy, jumping up in energy levels. 06:29: Those electrons then lose that energy by emitting light at specific wavelengths-- signature photons that are different for every element or molecule. 06:22: As these metals get jostled in a warm cloud, their electrons absorb energy, jumping up in energy levels. 06:29: Those electrons then lose that energy by emitting light at specific wavelengths-- signature photons that are different for every element or molecule. 06:22: As these metals get jostled in a warm cloud, their electrons absorb energy, jumping up in energy levels.
	2017-05-10: The Great American Eclipse 05:58: ... first time in your life, you see the chromosphere, red from a specific electron transition in the hydrogen of the sun's upper ...
	2017-05-03: Are We Living in an Ancestor Simulation? ft. Neil deGrasse Tyson 03:43: Let's avoid the idea that the entire universe is simulated, right down to every atom, electron, or vibrating quantum field.
	2017-04-19: The Oh My God Particle 01:48: High energy particles, electrons, and small atomic nuclei, as well as gamma rays, are ejected when heavier radioactive elements decay. 05:19: ... come in at all energies, from a sickly billion electron volts at the low end to the crazy 10 to the power of 20 electron volts ... 07:11: ... rays with energies over 5 times 10 to the power of 19 electron volts, about 8 joules, can't travel far before smacking into these ... 05:19: ... come in at all energies, from a sickly billion electron volts at the low end to the crazy 10 to the power of 20 electron volts or ... 07:11: ... rays with energies over 5 times 10 to the power of 19 electron volts, about 8 joules, can't travel far before smacking into these photons and ... 01:48: High energy particles, electrons, and small atomic nuclei, as well as gamma rays, are ejected when heavier radioactive elements decay.
	2017-04-05: Telescopes on the Moon 05:26: They stick to electronics, impede solar panel function, and grind away at moving parts, nasty stuff.
	2017-03-29: How Time Becomes Space Inside a Black Hole 12:02: The systems that were tested use electron spins, which pull on each other to cause a cascading flow of flipping spins the cycles back and forth.
	2017-03-15: Time Crystals! 04:07: These atoms have spin values, quantum mechanical angular momenta from their electrons. 04:57: I mean, you're basically grabbing the electrons and forcing them to oscillate. 05:01: But the paper proposes that if you let go of the electrons, their spin oscillations should continue. 08:34: ... approach to building a quantum computing memory element is to use electron spins, which can represent the ones and zeros of a classical computer in ... 04:07: These atoms have spin values, quantum mechanical angular momenta from their electrons. 04:57: I mean, you're basically grabbing the electrons and forcing them to oscillate. 05:01: But the paper proposes that if you let go of the electrons, their spin oscillations should continue.
	2017-02-15: Telescopes of Tomorrow 04:09: But uncool telescope electronics are even brighter.
	2017-02-02: The Geometry of Causality 13:30: ... 10 times the Schwarzschild shield radius, undergo an extremely energetic electron transition that produces X-rays at a very particular frequency, the ion ...
	2016-11-30: Pilot Wave Theory and Quantum Realism 14:45: You have an outer crust of conductive iron that can support an enormous current of electrons. 14:51: ... centimeters to meters deep in which you have significant impurities of electrons and protons mixed in with the neutrons, perhaps up to 10% electrons and ... 15:53: ... into a gas cataclysmically and the neutrons would decay to protons and electrons and an awful lot of ... 14:45: You have an outer crust of conductive iron that can support an enormous current of electrons. 14:51: ... centimeters to meters deep in which you have significant impurities of electrons and protons mixed in with the neutrons, perhaps up to 10% electrons and ... 15:53: ... into a gas cataclysmically and the neutrons would decay to protons and electrons and an awful lot of ...
	2016-11-16: Strange Stars 01:52: In that collapse, most of the electrons and protons are crunched together to form neutrons.
	2016-11-02: Quantum Vortices and Superconductivity + Drake Equation Challenge Answers 02:36: ... advanced electronic components are very likely, and it may even be possible to build a ...
	2016-10-26: The Many Worlds of the Quantum Multiverse 01:09: But to summarize, a stream of photons or electrons, or even molecules, travels from some point to a detector screen via pair of slits.
	2016-09-21: Quantum Entanglement and the Great Bohr-Einstein Debate 04:41: It involved entangled electron and positron pairs. 06:35: What if between creation and measurement, the electron and positron only exist as a wave function of all possible states. 07:57: Instead of looking at the entangled spins of an electron positron pair, he used photon pairs with entangled polarizations.
	2016-09-07: Is There a Fifth Fundamental Force? + Quantum Eraser Answer 00:37: Atomic nuclei have energy levels, just like their electron shells do. 00:54: One thing that comes out of a pile of beryllium-8 atoms is a lot of electron-positron pairs.
	2016-08-24: Should We Build a Dyson Sphere? 12:08: This is done with coincidence electronics.
	2016-08-10: How the Quantum Eraser Rewrites the Past 01:52: ... physicist is better at collapsing wave functions then observation by an electronic ...
	2016-07-27: The Quantum Experiment that Broke Reality 04:44: ... a single electron through a pair of slits and it'll also appear to land at a single spot ... 05:14: We have to conclude that each individual photon, electron, or buckyball travels through both slits as some sort of wave. 06:24: ... starts its journey wherever we put the laser or electron gun or buckyball trebuchet and it releases its energy at a well-defined ... 04:44: ... it'll also appear to land at a single spot on the screen but fire many electrons and they slowly build up the same sort of interference ...
	2016-07-20: The Future of Gravitational Waves 07:03: ... the Coulomb potential of the nuclear protons, reaches the 8.78 mega electron volts of the alpha particle's kinetic ...
	2016-07-06: Juno to Reveal Jupiter's Violent Past 11:19: A more color sensitive eye or electronic detector would see the sun as yellowish green.
	2016-06-22: Planck's Constant and The Origin of Quantum Mechanics 02:12: ... wavelength, but also the Schrodinger equation, the energy levels of electron orbits, and importantly, the relationship between the energy and ... 03:19: And so an object made of jiggling charged particles, like electrons and protons, glows. 02:12: ... wavelength, but also the Schrodinger equation, the energy levels of electron orbits, and importantly, the relationship between the energy and frequency of a ... 03:19: And so an object made of jiggling charged particles, like electrons and protons, glows.
	2016-06-01: Is Quantum Tunneling Faster than Light? 04:52: Protons, neutrons, electrons, and alpha particles can quantum tunnel into nuclei in various types of fusion and particle capture phenomena. 05:08: A variety of modern electronics also rely on the tunneling phenomenon, including the transistor. 04:52: Protons, neutrons, electrons, and alpha particles can quantum tunnel into nuclei in various types of fusion and particle capture phenomena.
	2016-05-04: Will Starshot's Insterstellar Journey Succeed? 04:09: ... payload will be a single wafer of electronics and would include multiple detectors, including a camera, small lasers ...
	2016-04-06: We Are Star Stuff 01:54: Along with a similar number of neutrons, and beyond the nucleus, electrons swarm in their quantized shells.
	2016-03-30: Pulsar Starquakes Make Fast Radio Bursts? + Challenge Winners! 03:18: At this time, the universe was full of plasma, atomic nuclei, and free electrons. 03:25: It's those electrons that were the problem for light. 03:27: You see, free electrons are really, really good at getting in the way of photons. 03:33: ... call a large scattering cross-section, which means that even though the electrons themselves are infinitesimally small, photons don't have to get too ... 04:03: But the approximation does allow us to estimate how far a photon can travel before encountering an electron. 04:10: By the way, the number that defines the size of the circle for electrons is called the Thomson scattering cross-section. 04:21: ... universe at this time, have much smaller scattering cross-sections than electrons ... 04:34: First, we need to figure out how close those electrons are to each other. 05:00: But what about the electrons? 05:11: ... 6 by 10 to the 79 protons in the observable universe, and just as many electrons. ... 05:42: All of those electrons existed at the moment of recombination. 05:46: So let's get the electron density back then. 06:11: ... that ridiculous number of electrons out evenly and we get that there were 200 million electrons in every ... 06:21: That's way up from the 0.2 electrons per cubic meter that we find now. 06:27: So how far would a photon have to travel before bumping into one of these electrons? 06:32: Think of each electron as a target, with a radius equal to it's scattering cross-section. 06:58: Any photon traveling that distance is probably going to have hit an electron. 07:07: ... length of the column has a fraction blocked equal to the number of electrons in that column segment, which is just electron density, times the ... 07:36: Now, we simplified here because some of those electron targets are going to overlap. 05:46: So let's get the electron density back then. 07:07: ... equal to the number of electrons in that column segment, which is just electron density, times the scattering cross-section of the ... 07:36: Now, we simplified here because some of those electron targets are going to overlap. 03:18: At this time, the universe was full of plasma, atomic nuclei, and free electrons. 03:25: It's those electrons that were the problem for light. 03:27: You see, free electrons are really, really good at getting in the way of photons. 03:33: ... call a large scattering cross-section, which means that even though the electrons themselves are infinitesimally small, photons don't have to get too ... 04:10: By the way, the number that defines the size of the circle for electrons is called the Thomson scattering cross-section. 04:21: ... universe at this time, have much smaller scattering cross-sections than electrons ... 04:34: First, we need to figure out how close those electrons are to each other. 05:00: But what about the electrons? 05:11: ... 6 by 10 to the 79 protons in the observable universe, and just as many electrons. ... 05:42: All of those electrons existed at the moment of recombination. 06:11: ... that ridiculous number of electrons out evenly and we get that there were 200 million electrons in every ... 06:21: That's way up from the 0.2 electrons per cubic meter that we find now. 06:27: So how far would a photon have to travel before bumping into one of these electrons? 07:07: ... length of the column has a fraction blocked equal to the number of electrons in that column segment, which is just electron density, times the ... 05:42: All of those electrons existed at the moment of recombination.
	2016-03-09: Cosmic Microwave Background Challenge 00:37: Free electrons were captured by protons to form the very first atoms. 02:42: ... universe was filled with this plasma that consisted mostly of protons, electrons, and helium ... 02:53: That plasma was effectively opaque because photons couldn't travel far without bouncing off all those free electrons. 03:01: ... universe became transparent when it cooled enough for those electrons to be captured by protons to form the first hydrogen atoms in an event ... 03:11: The question is what average distance could a photon travel before being scattered by an electron just before recombination? 00:37: Free electrons were captured by protons to form the very first atoms. 02:42: ... universe was filled with this plasma that consisted mostly of protons, electrons, and helium ... 02:53: That plasma was effectively opaque because photons couldn't travel far without bouncing off all those free electrons. 03:01: ... universe became transparent when it cooled enough for those electrons to be captured by protons to form the first hydrogen atoms in an event ...
	2016-03-02: What’s Wrong With the Big Bang Theory? 11:11: ... asks, does this mean if you were to take every proton, neutron, and electron in the universe, you could fit them all into a space the size of a grain ...
	2016-02-24: Why the Big Bang Definitely Happened 03:43: It was a searing ocean of protons and electrons.
	2016-02-03: Will Mars or Venus Kill You First? 05:27: This is when a magnetic storm on the sun's surface sends out a blast of extremely high energy particles, most notably protons and electrons.
	2016-01-27: The Origin of Matter and Time 06:28: ... for the most elementary components of the atom, in which the familiar electrons and quarks are composites of massless particles confined by the Higgs ... 09:26: ... any particle that can decay, or even oscillate between states, like the electron's chirality flip, is experiencing time, which goes hand-in-hand with them ... 09:38: However, quarks and electrons gain their intrinsic mass by interacting with the Higgs field. 09:48: The familiar electron is really a composite of the left and the right-handed chirality electron and anti-positron, which on their own are massless. 10:04: ... basic vibrations of their quantum fields-- the time that the electron or quark feels-- is felt by the composite particle, not by their ... 06:28: ... for the most elementary components of the atom, in which the familiar electrons and quarks are composites of massless particles confined by the Higgs ... 09:26: ... any particle that can decay, or even oscillate between states, like the electron's chirality flip, is experiencing time, which goes hand-in-hand with them ... 09:38: However, quarks and electrons gain their intrinsic mass by interacting with the Higgs field. 09:26: ... any particle that can decay, or even oscillate between states, like the electron's chirality flip, is experiencing time, which goes hand-in-hand with them having ... 09:38: However, quarks and electrons gain their intrinsic mass by interacting with the Higgs field.
	2016-01-13: When Time Breaks Down 01:11: ... gears are comprised of atoms vibrating in metal lattices, bound by electrons flickering in their orbits, themselves held in place by protons that are ... 01:47: But what about the quarks, the electrons? 02:09: Those electrons and quarks bounce around at such high speeds inside the atom that they experience time very differently to the atom itself. 06:22: Quarks and electrons confined first by their coupling with the Higgs field, and then by the forces binding them into atoms. 01:11: ... gears are comprised of atoms vibrating in metal lattices, bound by electrons flickering in their orbits, themselves held in place by protons that are ... 01:47: But what about the quarks, the electrons? 02:09: Those electrons and quarks bounce around at such high speeds inside the atom that they experience time very differently to the atom itself. 06:22: Quarks and electrons confined first by their coupling with the Higgs field, and then by the forces binding them into atoms. 01:11: ... gears are comprised of atoms vibrating in metal lattices, bound by electrons flickering in their orbits, themselves held in place by protons that are comprised ...
	2016-01-06: The True Nature of Matter and Mass 05:22: And as we saw recently, even those quarks, as well as electrons, gain their tiny masses from a type of confinement via the Higgs field. 09:06: Felix Feist points out that given that the right-handed electron doesn't have weak hypercharge, shouldn't it be massless? 09:14: The right-hand electron can interact with the Higgs field by picking up some weak hypercharge. 09:19: ... forth between handedness is probably more accurately thought of as the electron being both right- and left-handed at the same time, because the ... 09:32: There's a quantum blur surrounding the current state of the electron. 09:40: The naked left- or right-handed electron is massless. 09:06: Felix Feist points out that given that the right-handed electron doesn't have weak hypercharge, shouldn't it be massless? 05:22: And as we saw recently, even those quarks, as well as electrons, gain their tiny masses from a type of confinement via the Higgs field.
	2015-12-16: The Higgs Mechanism Explained 00:28: The electrons, and the quarks that comprise protons and neutrons, do seem to have intrinsic mass, but this is only run 1% of the mass of the atom. 01:16: For example, the electron is an excitation in the electron field. 01:20: Imagine that every point in the universe has a certain level of electron-ness. 01:28: But even in a vacuum, the electron field is there. 01:38: The field vibrates, and that vibration is our electron. 01:41: And it's not just electrons. 02:02: ... theory, as it stood in the 1950s, gave a perfect description of the electron, and yes predicted that the electron should have no ... 02:34: Take the electron. 02:51: The electron evolves, meaning it does experience time, so it must have mass. 03:30: But the photon and the electron are both just excitations in their own fields, so why does the electron have mass and the photon not? 03:38: Why does the electron evolve? 03:40: ... the entire observable universe without bumping into a single thing, the electron is never not bumping into ... 03:52: There's something in the substrate of space everywhere that impedes the electron. 04:15: See, left-handed electrons have this extra little something something compared to right-handed electrons. 04:26: ... like regular electric charge, which lets all electrons feel the electromagnetic force, except in this case, it lets only ... 04:48: ... fact, it cares so much that it won't let an electron flip from left to right unless it can ditch its weak hyper-charge or ... 05:34: ... poor electron is bombarded by a flow of particles into and out of the Higgs field from ... 05:44: On its own, the electron would travel at light speed, but trapped in this Higgs field buzz, the electron feels mass. 05:53: ... of some sort of charge that we've never heard of all invented so that electrons can be left and right-handed at the same ... 03:38: Why does the electron evolve? 02:51: The electron evolves, meaning it does experience time, so it must have mass. 05:44: On its own, the electron would travel at light speed, but trapped in this Higgs field buzz, the electron feels mass. 01:16: For example, the electron is an excitation in the electron field. 01:28: But even in a vacuum, the electron field is there. 04:48: ... fact, it cares so much that it won't let an electron flip from left to right unless it can ditch its weak hyper-charge or flip ... 01:20: Imagine that every point in the universe has a certain level of electron-ness. 00:28: The electrons, and the quarks that comprise protons and neutrons, do seem to have intrinsic mass, but this is only run 1% of the mass of the atom. 01:41: And it's not just electrons. 04:15: See, left-handed electrons have this extra little something something compared to right-handed electrons. 04:26: ... like regular electric charge, which lets all electrons feel the electromagnetic force, except in this case, it lets only ... 05:53: ... of some sort of charge that we've never heard of all invented so that electrons can be left and right-handed at the same ... 04:26: ... like regular electric charge, which lets all electrons feel the electromagnetic force, except in this case, it lets only left-handed ...
	2015-12-09: How to Build a Black Hole 02:03: Electrons are slammed into protons in the ion nuclei, forging a neutron star. 03:45: For example, electrons, protons, and neutrons. 04:02: Now, this rule is what keeps electrons in their separate stable orbits and, in turn, is part of what allows solid matter to have its structure. 02:03: Electrons are slammed into protons in the ion nuclei, forging a neutron star. 03:45: For example, electrons, protons, and neutrons. 04:02: Now, this rule is what keeps electrons in their separate stable orbits and, in turn, is part of what allows solid matter to have its structure. 03:45: For example, electrons, protons, and neutrons.
	2015-05-20: The Real Meaning of E=mc² 00:02: A hydrogen atom has less mass than the combined masses of the proton and the electron that make it up. 05:21: ... that the mass of a hydrogen atom is less than the combined masses of the electron and the proton that make it ... 05:32: Suppose we call the potential energy of a proton and electron zero when they're infinitely far apart. 05:48: So the potential energy of the electron and proton in a hydrogen atom is negative. 05:52: Now the electron in hydrogen also has kinetic energy, which is always positive, due to its movement around the product proton. 06:12: ... table weigh less than the combined masses of the protons, neutrons, and electrons that make them ... 06:54: All right, what about the masses of electrons and quarks? 07:12: For instance, there's the potential energy associated with the interactions of electrons and quarks with the Higgs field. 07:17: ... there's also potential energy that electrons and quarks have from interacting with the electric fields that they ... 06:12: ... table weigh less than the combined masses of the protons, neutrons, and electrons that make them ... 06:54: All right, what about the masses of electrons and quarks? 07:12: For instance, there's the potential energy associated with the interactions of electrons and quarks with the Higgs field. 07:17: ... there's also potential energy that electrons and quarks have from interacting with the electric fields that they ...
	2015-03-25: Cosmic Microwave Background Explained 03:06: At this temperature, it's too hot for electrons and protons to even coalesce into atoms, let alone stars, planets or galaxies. 03:22: ... plasma emitted just couldn't travel very far before it would run into an electron and ricochet like in a pinball ... 03:58: With no more free electrons to redirect the light, the universe became, for the very first time, transparent. 03:06: At this temperature, it's too hot for electrons and protons to even coalesce into atoms, let alone stars, planets or galaxies. 03:58: With no more free electrons to redirect the light, the universe became, for the very first time, transparent.

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