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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. 01:14: 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 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 ... 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 ...
	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. ...
	2022-09-28: 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 ... 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 ... 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. 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 ... 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 - ...
	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. 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? 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.
	2022-06-01: What If Physics IS NOT Describing Reality? 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: ... 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.
	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. 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 ...
	2022-01-27: 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. 07:05: Let’s say two electrons approach each other.
	2022-01-12: How To Simulate The Universe With DFT 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: ... them causing the particles to be drawn together or in the case of two electrons to be drawn apart and you might think that in that viewpoint if you ...
	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 ... 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 ... 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: ... 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. 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 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 ... 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 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? 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 00:47: ... 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: ... its position   we need to be able to say that all of the  electron’s mass is within a certain volume.   So defining position means ...
	2021-04-07: Why the Muon g-2 Results Are So Exciting! 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 ... 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 ... 01:49: 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 05:08: ... 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. 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 ... 02:31: ... 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 01:17: 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 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. 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 ...
	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 ...
	2020-06-30: 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 ... 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? 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.
	2020-04-22: 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.
	2020-03-16: How Do Quantum States Manifest In The Classical World? 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. 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? 02:13: 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? 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 ...
	2020-01-27: Hacking the Nature of Reality 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: ... how they were made. Neutrinos made in nuclear reactors are made with electrons and if they interact again, they make only electrons. In particle beams, ...
	2020-01-06: How To Detect a 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.
	2019-11-11: 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. 08:18: For example, if quarks or electrons had significantly different masses we’d once again be in a chemistry-free cosmos.
	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.
	2019-08-06: What Caused the Big Bang? 10:26: ... decay into the familiar particles of the standard model - quarks, electrons, ...
	2019-06-06: The Alchemy of Neutron Star Collisions 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 ... 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? 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.
	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 ... 02:09: 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 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 ...
	2018-12-12: Quantum Physics in a Mirror Universe 00:02: ... of cobalt-60 and watched them decay they found that almost all of the electrons produced in the decay emerged in the opposite direction to the nucleus ...
	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.
	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: ... 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.
	2018-10-10: 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. 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 10:31: ... quantum electrodynamics to allow incredibly precise calculation of the electron's ...
	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.
	2018-08-23: How Will the Universe End? 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 ... 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? 04:18: 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? 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.
	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?
	2018-02-21: 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 ...
	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.
	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.
	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 ... 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. 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.
	2017-09-28: Are the Fundamental Constants Changing? 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 12:14: 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 13:09: You'll always get the same number of electrons versus positrons.
	2017-08-10: The One-Electron Universe 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 10:43: ... 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 02:12: 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. 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: ... 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 ...
	2017-06-28: The First Quantum Field Theory 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. 03:24: 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.
	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.
	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.
	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 ...
	2016-11-16: Strange Stars 01:52: In that collapse, most of the electrons and protons are crunched together to form neutrons.
	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.
	2016-07-27: The Quantum Experiment that Broke Reality 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 ...
	2016-06-22: Planck's Constant and The Origin of Quantum Mechanics 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.
	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 ... 04:10: 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 ...
	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. 09:26: ... 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 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.
	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. 01:41: 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. 03:45: For example, electrons, protons, and neutrons.
	2015-05-20: The Real Meaning of E=mc² 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. 03:58: With no more free electrons to redirect the light, the universe became, for the very first time, transparent.

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