
20221208: How Are Quasiparticles Different From Particles?
 07:56: ...  basically, they have collisions, which can be electromagnetic interactions with other electrons, falling into a hole, ...
 09:05: ... the electrical resistance becomes zero, which in turn creates many cool interactions with electromagnetic fields, like levitating magnets, which you can use ...


20221123: How To See Black Holes By Catching Neutrinos
 02:18: ... astronomy might be challenging, given that each neutrino has a minuscule interaction probability most of them pass straight through your ...
 02:31: With enough neutrinos you will get interactions.
 03:38: ... highenergy neutrinos, interaction are with an atomic nucleus and that interaction can transmute the ...


20221116: Are there Undiscovered Elements Beyond The Periodic Table?
 09:54: Pairs of updown nucleons form these stablelittle spinzero partnerships in socalled nuclear pairing interactions.


20221019: The Equation That Explains (Nearly) Everything!
 01:48: ... of nature in terms of gauge symmetries. And they succeeded. The weak interaction arises from a slightly more complicated SU(2) symmetry, while the strong ...
 04:36: ... has to describe  namely, the particles of the standard model and their interactions with each ...
 06:02: ... and still others  perhaps the most important parts  deal with the interactions between the two. So let’s now take a tour through the standard model ...
 06:36: ... no matter whatsoever. The Fs are actually shorthand for the separate interaction of each of the three quantum ...
 08:23: ... need an extra term to describe the potential energy of that interaction, which we add to the kinetic term. Here we see a connection to the ...
 09:15: All these kinetic terms are summarized with the F’s, representing the motion of the bosons and their interactions with each other.
 10:36: ... charges are the coupling constants which represent the strength of each interaction. ...


20221012: The REAL Possibility of Mapping Alien Planets!
 15:45: ... the 3 quantum forces were coupled with a high joint interaction strength. However it’s really only meaningful to ...
 18:29: ... energy available in a particle interaction for the creation of the interaction products. It comes from particle kinetic energy, photon energy, ...


20220928: Why Is 1/137 One of the Greatest Unsolved Problems In Physics?
 02:36: ... levels of electrons with opposite spins are separated slightly by their interaction with their own orbital magnetic ...
 05:27: ... of particles interacting by all the different ways that interaction could ...
 05:42: These factors multiply a sort of base probability to make the interaction more or less likely.
 05:49: That base probability comes from the coupling constant or coupling strength for the interaction.
 06:02: ... say Feynman diagrams  it’s the base probability at each vertex, each interaction between electron and virtual photon, adjusted by all these other ...
 06:29: The more chance of interaction between the electron and electromagnetic fields, the more of an EM disturbance each electron will make.
 07:10: It changes with the energy of the interaction.


20220921: Science of the James Webb Telescope Explained!
 09:54: Those pointy things are diffraction spikes, caused by interactions of incoming light with the hexagonal aperture of the scope.


20220914: Could the Higgs Boson Lead Us to Dark Matter?
 02:17: ... Feynman diagram is just a way to represent the interactions of particles, plotting time versus space so we have two particles coming ...
 03:00: Of course this sort of interaction is incredibly rare  otherwise we’d have detected dark matter already.
 03:06: But with enough particles and enough time, we should eventually see an interaction between a dark matter particle and a matter particle.
 06:55: ... Large ElectronPosition Collider, but no evidence was found supporting interactions with dark matter, and so the Z is probably a dead ...


20220824: What Makes The Strong Force Strong?
 04:52: And this colourful convention led to the naming of our science of strong force interactions: quantum chromodynamics.
 11:40: ... is a strong interaction similar to magnetism called Chromomagnetism, but that's where the ...
 12:57: ... out, but it's not really neutral because the probability of the green interaction is double the other ...


20220803: What Happens Inside a Proton?
 01:31: ... LOOKS like three quarks from the outside. The messy interactions of quarks via gluons is described by quantum ...
 03:12: ... speed and angle. We do that by adding up all the possible ways that interaction could happen. For example there are various ways the ...
 04:17: ... kind of got lucky with that in the case of QED. As the interactions get more complicated, their probabilities get smaller and ...
 05:14: ... of the fine structure constant means the electromagnetic interaction is relatively weak. Relative to the strong force ...
 05:31: ... field. We can draw Feynman diagrams of these interactions, now with curly gluon lines. Presumably then to calculate the ...
 06:02: ... the strong force strong, and it’s also what makes strong force interactions very difficult to calculate. You no longer have the luxury of ...
 07:53: ... fields themselves evolve over the course of a strong force interaction. Similar to how Feynman diagrams work, to do this you need to ...
 10:43: ... space that get us from the start to the end of our interaction. But these can’t be totally random because some of these paths are ...
 14:08: ... approximation of what these messy fields are really doing during an interaction. ...


20220727: How Many States Of Matter Are There?
 04:43: OK, so a state of matter is an emergent behavior due to the interactions between components under particular conditions.
 05:53: But actually, the interactions between the gluons and quarks remain significant and so a quarkgluon plasma behaves more like a liquid.
 07:00: The stuff of quarks is generically called quark matter or QCD matter  for quantum chromodynamics  the physics of quark and gluon interactions.
 10:24: The frequent interactions between people cause liquidlike phenomena like currents and waves as individuals lose their autonomy of motion.
 10:57: Astrophysicists routinely model the galaxies as a sort of fluid of stars, where the interactions are not electromagnetic, but gravitational.
 11:28: The fact is, the concept of "states of matter" can help us to understand many kinds of interactions, even between macroscopic “particles”.


20220720: What If We Live in a Superdeterministic Universe?
 11:12: ... have argued that superdeterminism requires a kind of conspiracy of interactions to ensure that two messy meat computers make the right choices based on ...


20220630: Could We Decode Alien Physics?
 00:00: ... and a list of all elementary particles and their properties and interactions. If we can correctly decipher this stuff, we can build ...
 01:25: ... glance at the alien Maxwell’s equations which govern the interactions of charged particles will reveal that they use a ...
 05:33: ... So as long as our compendium of alien physics describes the interactions of specific particles, we can distinguish matter from ...
 10:41: ... alien user manual for the part that describes weak force interactions we should be able to figure out which handed rule the aliens ...
 11:52: ... in charge and parity would change how they represent their particle interactions in a way that we couldn’t distinguish. We might build a ...


20220601: What If Physics IS NOT Describing Reality?
 14:22: ... Ziak asks how galaxy interactions affect the galactic habitable zone, suggesting that it may ...


20220504: Space DOES NOT Expand Everywhere
 14:34: ... in this case manifests the universe. Rather than for example saying that “interaction” is doing the work. It’s very true that the choice of phrasing has led to ...
 16:05: ... interpretation is true, then what are entities that initiated the first interaction that brought everything into being? Actually, I think this is exactly ...


20220427: How the Higgs Mechanism Give Things Mass
 03:36: ... the next episode we tried the same trick to explain the weak interaction as arising from symmetries. We saw that we could invent a pair of ...
 05:38: ... this random thermal motion gets overpowered by the magnetic interaction and they end up all aligning. The equations of magnetism don’t ...
 12:59: ... We want to combine the weak and electromagnetic interactions, so we need simultaneous local U(1) and SU(2) symmetry. Let’s just ...
 15:06: ... mass and become the two W and one Z bosons of the weak interaction. The fourth boson manages to escape unscathed and massless, ...
 16:02: ... this new measurement of the W boson mass? Mass results from interaction with the Higgs field, but also all of the other subtle ...


20220420: Does the Universe Create Itself?
 00:59: ... fields, nor solely in the mind of the observer, but rather in the interaction of the ...
 12:05: ... “Observation” could well be code for “interaction”, in which every time two particles bump together and become entangled we ...


20220323: Where Is The Center of The Universe?
 16:27: Al H asks what particles and interactions existed before the electroweak force split into electromagnetism and the weak force.


20220316: What If Charge is NOT Fundamental?
 05:50: The conservation of fundamental properties defines which interactions are possible and which are impossible.
 05:57: Charge alone couldn’t explain the patterns of interactions and particle types observed in the particle zoo.
 10:52: To fully explain weak interactions we need a second charge  this one carried by the Z boson.


20220216: Is The Wave Function The Building Block of Reality?
 08:02: ... frenetic Brownian motion of pollen grains floating on water. Matter’s interaction with this fluctuating field would continuously collapse the wave ...


20220210: The Nature of Space and Time AMA
 00:03: ... emerge from connections between points in a graph that have rules of interactions between them okay and according to from the kind of the smoothness of ...


20220127: How Does Gravity Escape A Black Hole?
 08:06: ... Interactions between particles result from the sum of all virtual particle ...
 08:19: The overall interaction, along with any information that it communicates has to be sublightspeed.
 13:25: Starting with the quantum, manonthedollar asks  given the incredible amount of power required to simulate quantum interactions...
 13:33: do the ACTUAL interactions also require that much effort from the universe?
 14:27: ... tells us that you do include Coulomb and exchange interactions even in your initial guess, and that the remaining part you have to ...


20220119: How To Build The Universe in a Computer
 00:47: ... we’ve calculated the chaotic gravitational and hydrodynamic interactions of countless stars and gas and dark matter particles over billions of ...
 06:00: ... nearby particles it’s important to consider every individual interaction, but for more distant locations it’s okay to clump particles ...
 07:33: Modern mesh codes also do classic particleparticle interactions at short ranges to improv accuracy at small scales.
 09:05: ... SPH for large scale flows and particleparticle Nbody for smallscale interactions. ...


20220112: How To Simulate The Universe With DFT
 15:57: ... possible to imagine a scenario where the black hole had multiple interactions on its way to the Earth  perhaps it punctured the Sun, swung around ...


20211210: 2021 End of Year AMA!
 00:02: ... and that answer goes something like this so when you calculate the interaction between two particles whether they're repelled or attracted using ...


20211020: Will Constructor Theory REWRITE Physics?
 09:04: That entanglement has to be initially induced by a local interaction  the qubits must come into contact.


20211013: New Results in Quantum Tunneling vs. The Speed of Light
 02:52: ... measurement, or upon interaction with another particle, the proton can end up anywhere within that ...


20210818: How Vacuum Decay Would Destroy The Universe
 03:11: ... elementary particles that have mass gain their mass due to interactions with this ubiquitous field. I go into all the detail of ...


20210721: How Magnetism Shapes The Universe
 15:15: For example Zapp Brannigan asks what percentage of quantum interactions separate into worlds versus recombining again.


20210713: Where Are The Worlds In Many Worlds?
 07:23: ... because the many, many interactions that these wavefunction branches experience on their way to your brain ...
 12:07: Splitting happens when phase relations are scrambled due to interactions  and that’s  the entire universe doesn’t split with every atomic wiggle.


20210609: Are We Running Out of Space Above Earth?
 05:41: I already mentioned that orbits decay due to interaction with the upper reaches of Earth’s atmosphere.
 14:43: The gravitational interaction is weak except right next to the relic  on the scale of Planck lenfths.


20210519: Breaking The Heisenberg Uncertainty Principle
 00:25: ... example, the recent g2 experiment for measuring the muon’s interaction with quantum fields is good to to one part in a billion And also pretty ...


20210421: The NEW Warp Drive Possibilities
 14:52: That said, there are other ways to track a particle’s interactions with virtual particles.
 15:01: ... distribution of those decays products are sensitive to the complex interactions with virtual particles that happen during the ...


20210407: Why the Muon g2 Results Are So Exciting!
 02:05: One of the interactions that QED describes is how a charge particle will tend to rotate to align with a magnetic field.
 02:13: The strength of that interaction is defined by something called, the gfactor for the particle.
 04:33: In this theory, electromagnetic interactions result from charge particles communicating by exchanging virtual photons.
 04:41: In QED, you figure out the strength of an interaction by counting up all the ways that this interaction could occur.
 05:02: We depict these interactions in Feynman diagrams.
 05:05: Each Feynman diagram represents one family of ways that the interaction could proceed.
 05:10: And the sum of all possible Feynman diagrams, gives you the interaction strength.
 05:45: But there are other ways this interaction can happen.
 06:02: Adding this interaction allowed Julian Schwinger to calculate a slightly higher value of g equals 2.0011614.
 06:10: Over time, more and more complicated interactions were added.
 06:12: Each layer of complication involve many more Feynman diagrams, but also added less and less to the interaction.
 06:48: Measure that leftover bit and you are testing the sudless interactions of the particle.
 07:36: So you add up all of the Feynman diagram to all possible electromagnetic interactions of the muon, but you don't stop there.
 07:48: There can be very subtle interactions that involve the other forces, weak, strong, and even the Higgs field.
 08:19: The probability of interaction between a particle and some massive virtual particle is proportional to mass squared.


20210323: Zeno's Paradox & The Quantum Zeno Effect
 08:55: ... to perform a measurement without interacting with a system, and that interaction has consequences beyond just increasing our ...
 09:04: If the measurement interaction is subtle enough then you might hope to gain that info without perturbing the system too much.
 10:20: Any interaction causes information to quickly spread into the environment.
 11:24: Your interaction with the wavefunction causes it to decohere  which means two things  you perturb the system in a nonsubtle way.
 12:10: And perhaps some of this is just semantic  for example, how do we really define measurement and interaction?


20210224: Does Time Cause Gravity?
 10:35: ... Interaction of those waves with matter right after inflation may have caused ...


20210126: Is Dark Matter Made of Particles?
 10:22: ... it also turns out that the interaction strength of dark matter is extremely important  it may have governed ...
 11:25: But a WIMP, with its extremely weak interaction, would more easily dodge its antimatter buddy  and so countless may have survived to this day.
 11:36: ... it turns out you can do a calculation of what interaction strength such a relic particle would need to have in order to survive in ...
 11:45: And that interaction strength is about the same as the weak interaction.


20210112: What Happens During a Quantum Jump?
 02:55: ... the wavefunction”, which these days is more often taken to mean that interaction with the environment causes the state transition  causes the quantum ...


20201222: Navigating with Quantum Entanglement
 10:40: ... were just interacting due to their magnetic fields  socalled spinspin interactions  rather than true entangled states  their spin state wouldn’t be ...


20201208: Why Do You Remember The Past But Not The Future?
 07:14: Let’s look at the asteroid after its very last interaction with the outside universe.
 07:56: Just rewind the clock to the moment before the asteroid’s very last interaction with the outside universe.
 10:45: But memory formation results from interactions with our environments  the generation of correlations.


20201118: The Arrow of Time and How to Reverse It
 06:19: ... entropy decreasing on the other. Zoom in to individual particle interactions and you see perfect reversibility of the laws of physics, but zoom out ...
 10:58: ... went thorugh another phase transition  a vacuum decay  then the weak interaction would fundamentally change  to become a different force with different ...


20201111: Can Free Will be Saved in a Deterministic Universe?
 05:59: The outcome of quantum interactions are chosen in fundamentally unpredictable ways.


20201104: Electroweak Theory and the Origin of the Fundamental Forces
 00:57: Let’s start with the mysterious and often misunderstood weak interaction.
 01:46: Enrico Fermi made the first attempt at a full quantum description of beta decay with his ‘four fermion’ interaction.
 01:54: Basically, he tried to model this as a direction interaction  in which all four “fermion” particles literally touch.
 02:10: Fermi was motivated by the apparent extreme short range of the interaction  and that short range is what earned it the name “weak” interaction.
 02:19: But Fermi’s model only worked at low energies, and neither it nor its successors explain why the weak interaction violates chargeparity symmetry.
 03:06: In 1957, Julian Schwinger proposed a set of force mediating gauge bosons for the weak interaction.
 03:12: Given that the weak interaction could change a neutral particle into a pair of charged particles this mediating particle must itself be charged.
 03:33: ... bosons’, W bosons, had to have mass due to the short range nature of the interaction, quite a lot of mass it in ...
 04:02: Anyway, this new gauge theory of the weak interaction seemed to be okay with parity violation, and it wasn’t only accurate at low energies.
 10:13: However, if we cool the material down, the interactions between magnetic particles can start to come into play.
 11:14: Well remember that I said that the weak interaction somehow seems to involve electromagnetism?


20201020: Is The Future Predetermined By Quantum Mechanics?
 07:31: More physicists prefer the idea of a nonconscious interaction causing the collapse.


20200921: Could Life Evolve Inside Stars?
 07:34: ... doesn’t go into detail, except to say that it might be catalyzed by interactions with atomic nuclei in the ...


20200908: The Truth About Beauty in Physics
 06:15: So is base reality represented by the simplest possible interaction or relationship, expressible with the simplest conceivable mathematical statement?
 15:40: The point is that there are some insanely rare interactions and extremely subtle deviations from the predictions of the standard model.


20200824: Can Future Colliders Break the Standard Model?
 06:02: ... other things, those counterparts should help cancel out the interactions of the known particles with the elementary quantum fields on which those ...
 11:26: It will smack electrons into protons and other nucleons to probe the details structure and interactions between quarks.
 15:53: David Kosa asks how would we describe the interaction of two merging stars of equal mass whose combined mass exceeds the Chandrashekar limit?


20200810: Theory of Everything Controversies: Livestream
 00:00: ... people it means a unified theory of the elementary particles and the interactions and that's a hope which has been ongoing for a long time and there ...


20200708: Does Antimatter Explain Why There's Something Rather Than Nothing?
 05:19: ... it must have the same mass, the same quantum energy levels, and the same interactions with its ...


20200630: Dissolving an Event Horizon
 14:17: ... supposedly have “zero size”, but they also have something called an interaction crosssection, which defines the probability of another particle ...
 14:40: ... you rescale both space and time by the same factor, you also rescale the interaction probabilities to that the interaction rate scales in the same way ... So ...


20200615: What Happens After the Universe Ends?
 07:53: ... not some fundamental property of those particles  they come from the interactions of those particles with quantum fields  the Higgs field in the case of ...
 08:39: And that’s precisely true for things like quarks and electrons, which gain their masses from interactions with the Higgs field.


20200422: Will Wormholes Allow Fast Interstellar Travel?
 14:59: ... Leo also asks whether these bubbles might be caused by dark matter interactions with the black hole. I'm afraid I don't know of any theory of dark ...


20200414: Was the Milky Way a Quasar?
 03:52: This is mostly from cosmic ray interactions with the interstellar medium.
 06:47: ... a shake  for example, if the galaxy is shaken by a collision or close interaction with another galaxy  then that gas can form stars at a really insane ...


20200316: How Do Quantum States Manifest In The Classical World?
 12:33: ... example of a pointer state is the position of a particle. Most quantum interactions depend heavily on the relative location of interacting particles. ...


20200303: Does Quantum Immortality Save Schrödinger's Cat?
 14:28: ... experiment is usually performed in a vacuum, and if not, why doesn’t interaction with gas cause immediate ...
 14:43: ... and precious, so you don't want to be losing or disturbing them by interactions with the air  so most are done in near ...
 14:54: ... experiment without actually scattering off air particles, and more minor interactions don't necessarily decohere the light  instead they introduce small ...


20200211: Are Axions Dark Matter?
 11:08: ... be ... dark matter. They have all the right properties  no direction interaction with light, and only weak interactions via the other forces. And ...


20200203: Are there Infinite Versions of You?
 14:48: But in smatrix theory and quantum field theory, time and space in the interaction region are fuzzy.
 15:00: Imagine an interaction where an electron emits a virtual photon which then deflects another particles  say, a proton.
 15:08: ... exactly the same interaction as if the proton emitted the photon to deflect the electron  in other ...


20200127: Hacking the Nature of Reality
 02:16: ... by vibrations in elementary fields that fill the universe, and all interactions are calculated by adding up the exchanges of infinite number of virtual ...
 02:41: Early quantum theory was plagued by problems  for example, how do you compute infinite interactions?
 02:48: And how do you avoid the infinite interaction strengths produced by some of those infinite sums?
 02:55: ... accurate predictions of quantum electrodynamics, which describes the interactions of the electromagnetic ...
 04:55: The idea was invented by John Archibald Wheeler in the late 30s as a convenient way to express the possible results of a quantum interaction.
 05:12: In standard use, the Smatrix can be calculated if you understand the forces in the interaction region  for example, in the nucleus of an atom.
 05:22: But what if you don’t know those internal interaction forces?
 05:34: The Smatrix was to become the physics of the interaction, rather than an emergent property of more fundamental, internal physics.
 06:47: Remember, that quantum field theory fastidiously adds together a complete set of virtual interactions that contribute to the real interaction.
 07:12: ... and the assumption of a family of particles that can be involved in the interaction. ...
 07:23: But in order to avoid those sums of Feynman diagrams, Smatrix theory also relies on symmetries between those virtual interactions.
 07:36: ... diagram and helps us ignore the actual causal structure within the interaction ...
 08:35: Before quarks and their interactions were properly understood, doing that sum seemed impossible in the case of strong force interactions.
 11:35: ... theory was born  at first as a description of strong nuclear force interactions before quantum chromodynamics took over  but then as a theory of ...
 12:27: ... bootstrap to understand the nature of those early subatomic scale interactions based only on current observations  which in this case is the ...


20200120: Solving the Three Body Problem
 04:24: But those orbits eventually shift due to the interactions between the planets.
 10:19: ... problem has appeared, which transforms the chaotic nature of threebody interactions into a useful tool, rather than a ...
 14:24: ... interact in the argon, we can see the path of the particles made in the interaction. From that, we can reconstruct the collision and learn more about ...


20191111: Does Life Need a Multiverse to Exist?
 04:18: ... chemical interactions give us different states of matter and a vast family of molecules, which ...
 08:05: ... are determined by the interaction of those particles with the Higgs field  but again, there’s no apparent ...


20190923: Is Pluto a Planet?
 16:47: The magnetic field that it does have comes from the interaction of the solar wind with its super thick atmosphere.


20190903: Is Earth's Magnetic Field Reversing?
 09:41: ... could be an asteroid or comet impact, an interaction between the core and mantle – for example the formation of a new magma ...


20190819: What Happened Before the Big Bang?
 02:55: They do this through a process called self interaction.
 03:11: This self interaction gives the field some potential energy.


20190701: Thorium and the Future of Nuclear Energy
 15:29: ... black hole killing star formation thing seems like a negative feedback Interaction more gas equals more active black hole equals more outward radiation and ...


20190509: Why Quantum Computing Requires Quantum Cryptography
 14:57: AspLode asks about the interaction between dark matter and black holes.


20190410: The Holographic Universe Explained
 04:00: And how do interactions on that surface correspond to interactions in the volume?
 06:11: ... the shapes of the pixels, which corresponds to not changing the rules of interaction. ...
 10:23: ... of 3+1 dimensions on which their lived a field theory that arose from interactions between ...
 11:46: ... interactions in the lower dimensional field theory are extremely strong – we would ...
 13:23: The rules of interactions between cells on the surface is a quantum field theory.
 13:28: But those rules translate to interactions in the volume – in the bulk – and there they are a theory of gravity.


20190320: Is Dark Energy Getting Stronger?
 02:40: ... of some unknown type, cold, diffuse, and immune to electromagnetic interactions of any ...


20190207: Sound Waves from the Beginning of Time
 03:08: ... interaction between the charged particles of the plasma via the trapped photons ...


20190124: The Crisis in Cosmology
 15:47: ...as demonstrated by the different forward/backward reaction rates in certain quantum interactions.


20190116: Our Antimatter, Mirrored, TimeReversed Universe
 03:02: ... of the standard model the great parity violating process is the weak interaction which only affects left chiral fermions right chiral fermions don't feel ...
 10:54: ... either direction they were not the same reversing the direction of the interaction changed something fundamental about the physics indicating a violation ...


20190109: Are Dark Matter And Dark Energy The Same?
 06:15: The author uses these ideas about the interactions of negative and positive mass particles to create an Nbody simulation.


20181212: Quantum Physics in a Mirror Universe
 00:02: ... are the same particle which turns out to be the K on and that the weak interaction which governs this decay does not concern parity but how to test this Yi ...


20181121: 'Oumuamua Is Not Aliens
 09:22: ... Oort cloud and was socked from its orbit by impact and or gravitational interaction into a trajectory that will send it to the ...
 14:35: ... passing through matter, interactions with the electromagnetic field change the effect of mass of the neutrino ...
 16:45: The same interactions happen in rock, but the Cherenkov radiation doesn't get very far.


20181114: Supersymmetric Particle Found?
 05:09: But in those interactions, cosmic rays can create extremely high energy neutrinos.
 06:08: ... very highest energy neutrinos, the ones that are produced by cosmic ray interactions with the ...


20181107: Why String Theory is Right
 03:55: But in very strong gravitational interactions, that intersection itself becomes more and more point like.
 04:15: If you even try to describe very strong gravitational interactions, you get nonsense black holes in the math.
 04:45: Now let's look at the interaction of two strings.
 04:53: Even the most energetic interactions are smeared out over the string, so you avoid the danger of black hole creating infinities.


20181031: Are Virtual Particles A New Layer of Reality?
 00:29: And every time two particles interact, an infinite number of virtual particles mediate infinite versions of that one interaction.
 02:12: In particle interactions, packets of energy are exchanged between these fields.
 03:02: The hack is to approximate this single multilayered mess of an interaction by adding together a set of much simpler idealized interactions.
 03:12: Those interactions are mediated by virtual particles.
 03:43: Then you add the effects of doing this transfer in two, three, four packets, as well as every other idealized field interaction that you can imagine.
 03:54: Every one of these interactions is described with a simple excitation and transfer of particles virtual particles.
 04:02: The hope is that by adding together the contributions of enough of these, you can approximate the messy state of the field in the true interaction.
 04:12: We call these idealized interactions intermediate states or virtual states of the field.
 04:39: ... of which intermediate states are important in your calculation of an interaction and which you can ...
 08:42: So that's the deal with virtual particles in particle interactions, but we also hear about the role of virtual particles in a complete vacuum.


20181018: What are the Strings in String Theory?
 02:09: ... in the interactions between pairs of mesons, as well as an odd relationship between their ...
 02:32: A lot of work went into figuring out a quantum theory for the strong interaction based on the physics of strings.
 09:10: ... our episode on quantum gravity, if you try to describe gravitational interactions on the smaller scales, the energies required to interact on that scale ...
 09:37: Its interactions are smeared around that string, handily avoiding the explosion of mathematical infinities you get below the Planck length.


20181003: How to Detect Extra Dimensions
 13:45: So when you use perturbation theory to calculate an interaction in field theories, feedback effects give infinite loops of interactions.


20180920: Quantum Gravity and the Hardest Problem in Physics
 05:32: The more precisely you want to measure position, the higher the energy of that interaction.
 09:48: ... a scheme to calculate a complex interaction, like the buzzing electromagnetic field around an electron, with a series ...


20180815: Quantum Theory's Most Incredible Prediction
 06:35: It seethes with a faint quantum buzz, infinite phantom oscillations that add infinite complication to any electromagnetic interaction.
 06:45: This messiness messes with the interaction of the electron and the magnetic field to shift the G factor slightly.
 07:27: Quantum field theory describes the interactions between particles as the sum total of all possible interactions that can lead to the same result.
 07:36: In the case of electromagnetism, those interactions are mediated by virtual photons, which are just a mathematical way to describe quantum buzz.
 07:45: Every interaction with virtual photons that can happen, does, at least in a sense.
 07:51: And the sum of the infinite possible interactions defines the strength of the one real interaction.
 08:17: They represent the possible interactions of the quantum field by way of virtual photons.
 08:22: And they tell you which interactions are the most important and which are insignificant.
 08:30: A basic interaction of an electron with an EM field is illustrated by this partial Feynman diagram.
 08:54: ... to the same overall result. But now the electron undergoes an additional interaction with the buzzing quantum ...
 09:04: ... need to include this sort of secondary interaction when we calculate, say, the overall strength of an electron's ...
 09:17: If we consider only the first interaction I showed along with similar primary ones, you calculate a G factor of exactly 2.
 09:26: But if you include this secondary interaction, you get g equals 2.0011614.
 10:04: The more complicated the interaction, the less it contributes to the overall effect.
 11:32: This is the fundamental constant governing the strength of the electromagnetic interaction of charged particles.


20180725: Reversing Entropy with Maxwell's Demon
 07:22: ... must start in some known predictable state, which is altered by interaction with a particle into some unknown ...


20180711: Quantum Invariance & The Origin of The Standard Model
 10:12: These are, the gauge bosons, the photon for electromagnetism, the W and Z bosons for the weak interaction, and the gluon for the strong interaction.
 10:21: Together, they govern the interactions of the metaparticles of the standard model.


20180704: Will A New Neutrino Change The Standard Model?
 01:00: They don't even interact via the weak interaction.
 01:22: ... can detect regular neutrinos by watching for the rare interaction between a neutrino and an atomic nucleus in some huge volume of matter, ...
 01:44: So, how on earth do you spot a sterile neutrino that doesn't even undergo that interaction well, by being extremely clever, obviously.
 04:42: ... particles that oscillate back and forth between those particles through interactions with the Higgs ...
 05:32: This interaction is opt for antimatter.
 05:46: Every neutrino we've ever observed was spotted using the weak interaction.
 07:21: Rare interactions with nuclei in the oil reveal the nature of the neutrinos.


20180620: The Black Hole Information Paradox
 09:16: ... quantummechanical interior of a black hole could be fully described by interactions on a 2D surface that did not include ...
 14:49: ... whether that's because of virtualparticle interaction with the interior or just the persistence of the field at the event ...


20180516: Noether's Theorem and The Symmetries of Reality
 08:08: They predict a rich family of conserved charges that govern the interactions of the particles of the standard model.
 08:14: For example, the color charge of quantum chromodynamics describes the strong interaction between quarks and gluons.
 08:30: ... symmetries really are and how they lead to the family of particles and interactions that make up our ...


20180509: How Gaia Changed Astronomy Forever
 05:46: And mapping globular clusters and dwarf galaxy orbits also tells us about future interactions with the Milky Way.


20180328: The AndromedaMilky Way Collision
 05:06: They used simulations of the gravitational interactions of millions of particles representing groups of stars and dark matter.
 06:09: Gravitational interactions with stars slingshots those stars into larger orbits or even completely out of the galaxy.


20180321: Scientists Have Detected the First Stars
 05:34: But in order to cool the hydrogen, there must be another type of interaction.


20180228: The Trebuchet Challenge
 02:27: After all, the interactions between particles are ultimately due to fundamental forces, which are always conservative.


20180214: What is Energy?
 08:50: ... the motion of a single particle in Schrodinger's equation to complex interactions of particles and fields in quantum field ...


20180131: Kronos: Devourer Of Worlds
 07:08: ... ends up in the inner part of the system, either by migration due to interactions between planets or if the gas giant is perturbed by a passing star into ...


20180117: Horizon Radiation
 00:12: This theory tells us that particles can be created and destroyed during interactions.
 03:14: ... or orbiting a black hole, should agree on the basic result of that interaction two photons in, one electron, one positron ...
 03:44: ... the equations describing the interaction transform cleanly between inertial reference frames in a way that leaves ...
 04:08: To see how this happens, we need to think about how particles, interactions, and vacuums are described in quantum field theory.
 08:28: ... new particles or remove old ones, for example, to describe a particle interaction like those two photons annihilating into an electron, positron ...


20171129: Citizen Science + ZeroPoint Challenge Answer
 08:42: ... shorter than 0.1 millimeters definitely exist, and we see particle interactions that require the exchange of much shorter wavelength virtual ...


20171019: The Nature of Nothing
 04:20: ... and they seem to be the machinery under the hood of all particle interactions in the universe, at least as described by quantum field ...
 04:41: Virtual particles are the links governing all particle interactions in the famous Feynman diagrams.
 04:48: But to properly calculate an interaction of real particles, every imaginable behavior of the connecting virtual particles must be accounted for.
 06:23: ... only the quantum possibilities of particles, which somehow govern the interactions of real particles without themselves being burdened with ...


20171011: Absolute Cold
 09:39: And when galaxies get stirred up by an interaction or collision with another galaxy, we expect that gas will be driven into the core also.


20171004: When Quasars Collide STJC
 07:30: Basically, the black holes slingshot stars outwards through gravitational interactions.


20170928: Are the Fundamental Constants Changing?
 05:48: There are two stable configurations for this interaction the little bar magnet may be aligned with the orbital field, or opposite to it.


20170810: The OneElectron Universe
 09:22: ... asked you to draw all of the twovertex and fourvertex diagrams for the interaction where electrons and positrons scatter off each other using the simple ...
 10:05: As long as the incoming and outgoing particles have the same momenta, these two are part of the same overall interaction.


20170802: Dark Flow
 09:54: Last week, we talked about the actual rules by which Feynman diagrams can be used to describe real interactions in quantum electrodynamics.
 10:04: ... couple of you pointed out 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 of that ...


20170726: The Secrets of Feynman Diagrams
 01:27: ... diagram represents a family of interactions and tells us the equation needed to calculate the contribution of that ...
 01:38: The miracle of Feynman diagrams is that an absurdly simple set of rules allows you to easily find all of the important interactions.
 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 antimatter counterparts, the positron; and photons.
 02:59: Particle/field interactions are represented as a vertex, a point where the lines representing the different particles come together.
 03:20: This vertex alone represents six very different seeming interactions.
 04:29: Every single QED interaction is built from these.
 04:33: But why only this interaction?
 05:21: Before we look at those more complex interactions, here's another important rule.
 05:25: The overall interaction described by a set of Feynman diagrams is defined by the particles going in and the particles going out.
 06:06: Each possible diagram that results in the same ingoing and outgoing particles is a valid part of the possibility space for that interaction.
 06:52: Let's go back to the simple interaction we looked at in our recent episode.
 06:56: Electron scattering can be depicted as two electrons going into an interaction and then two electrons going out.
 07:37: Part of the beauty of Feynman diagrams is that each of these diagrams themselves represents an infinite number of specific interactions.
 08:16: ... or the second to the first, even though this seems like a very different interaction. ...
 09:20: The same particles go in and out, but now, the interactions look very different.
 09:51: The interpretation of the interactions is irrelevant.
 10:02: ... field theory calculations, vastly reducing the number of contributing interactions that need to be separately ...


20170719: The Real Star Wars
 15:30: The socalled bare mass of an electron comes from its interaction with the Higgs field.
 15:36: ... not the same as the self energy interaction, but it's analogous in some ways the Higgs field exchange is weak ...
 15:51: It's a very different interaction to the self energy interaction, but the result is the same.
 15:56: ... mass comes from its interaction with other fields, be it the Higgs field for the bare mass, or the ...
 16:51: Every one of those vertices represents an interaction between the electron and the electromagnetic fields.
 16:57: The probability of that interaction is governed by the coupling constant between those fields.
 17:28: ... every additional interaction between the EM and the electron field, so every additional vertex, ...


20170712: Solving the Impossible in Quantum Field Theory
 03:08: ... field theory, but they also serve to give a general idea of what these interactions look ...
 03:38: But Feynman diagrams aren't really just drawings of the interaction.
 05:53: With infinite possible interactions behind this one simple process, a perfectly complete quantum field theoretic solution is impossible.
 06:32: In the case of electron scattering, the most likely interaction is the exchange of a single photon.
 06:43: In fact, the more complicated the interaction, the less it contributes.
 06:50: It turns out that the probability amplitude of a particular interaction depends on the number of connections, or vertices, in the diagram.
 06:59: Every additional vertex in an interaction reduces its contribution to the probability by a factor of around 100.
 07:08: So the most probable interaction for electron scattering is the simple case of one photon exchange with its two vertices.
 07:17: A threevertex interaction would contribute about 1% of the probability of the main twovertex interaction.
 07:24: However, it turns out that for electron scattering, there are no threevertex interactions.
 07:29: ... there are several interactions that include four vertices, and each contributes about 1% of 1% of the ...
 07:56: And more complicated interactions add even less to the probability.
 08:21: ... is especially true for socalled loop interactions, like when a photon momentarily becomes a virtual particleantiparticle ...
 11:08: ... successfully describe everything from particle scattering, selfenergy interactions, matterantimedia creation and annihilation, to all sorts of decay ...


20170628: The First Quantum Field Theory
 05:31: However, understanding the behavior of light and its interaction with matter required a different approach.
 06:38: ... given quantum event or interaction can happen in multiple different ways and the probability of the ...
 08:13: Dirac wasn't the first to come up with this idea but he was the first to successfully apply it to describing electromagnetic interactions.
 08:43: And there's another reason this second quantization is better at describing the interactions of light and matter.
 09:02: Yet, in particle interactions, particles are created and destroyed all the time.
 09:29: The resulting quantum electrodynamics describes the interactions of matter and radiation with stunning success.


20170503: Are We Living in an Ancestor Simulation? ft. Neil deGrasse Tyson
 15:17: That perfect time reversal would include the reverse of every particle interaction that happened in the original expansion.
 15:26: Now it's those same particle interactions that gives rise to pressure.
 15:33: Interactions can drive particles either outwards or inwards.
 15:37: Because particles can be pushed beyond the edge of the cloud, there end up being somewhat more interactions driving particles outwards than inwards.
 15:57: ... and velocities could be found such that the subsequent series of interactions leads to a large increase in ...


20170329: How Time Becomes Space Inside a Black Hole
 11:53: It refers to any quantum systems whose internal interactions result in a periodic change from one state to another and then back again.


20170315: Time Crystals!
 05:54: The analogous phase diagram for time crystals plots interaction strength between atoms versus imperfection in the spinflip driving signal.
 06:08: ... the variations in the forcing signal become too messy and the interaction strength is too weak, then the time crystal effectively melts into ...
 07:36: ... asymmetry melting when subjected to too much perturbation or too little interaction ...


20170301: The Treasures of Trappist1
 03:48: ... be that internal heat left over from formation and generated by tidal interactions with its star and the other planets could warm it to liquid water ...


20161026: The Many Worlds of the Quantum Multiverse
 07:07: ... diverge into different possibilities for example, at every particle interaction everywhere in the ...


20160929: Life on Europa?
 11:30: Rather, observation may just mean any interaction that destroys quantum coherence between the entangled particles.
 11:37: ... way of saying that is that this measurement interaction effectively entangles the measured particle and its partner with a ...


20160921: Quantum Entanglement and the Great BohrEinstein Debate
 07:49: Any interaction can destroy the entanglement.


20160907: Is There a Fifth Fundamental Force? + Quantum Eraser Answer
 03:51: But the researchers suggest it could mediate interactions between the socalled dark sector and the visible universe.


20160810: How the Quantum Eraser Rewrites the Past
 07:54: Part of the appeal of the Copenhagen interpretation is that it avoids any physical interaction that moves faster than light.
 08:18: But if these wave functions are physical, as the Copenhagen Interpretation would tell us, then there is no real instantaneous physical interaction.


20160727: The Quantum Experiment that Broke Reality
 09:02: That interaction increases the chance that some paths become real and decreases the chance of others.
 09:08: There's an interaction between possible realities that is seen in the distribution of final positions in the interference pattern.


20160615: The Strange Universe of Gravitational Lensing
 12:48: Some interpretations suggest that an observation means any interaction that is thermodynamically irreversible.


20160330: Pulsar Starquakes Make Fast Radio Bursts? + Challenge Winners!
 03:48: We can simplistically think of this interaction region as a solid circle.


20160203: Will Mars or Venus Kill You First?
 08:03: ... the interaction of the sun's magnetic field with Venus's think atmosphere actually ...
 09:16: ... way of saying that there have been around 13.8 billion years worth of interaction and change since the Big Bang for things in our reference ...


20160127: The Origin of Matter and Time
 06:17: ... massless light speed components confined not by mirrored walls, but by interactions with other particles and force ...
 06:28: ... and quarks are composites of massless particles confined by the Higgs interaction. ...
 06:42: In this analogy, those clock ticks become interactions between the internal parts of our atoms and nucleons.
 06:50: At each interaction, particles exchange energy, charge, and other properties that result in change.
 08:14: Those interactions which proceed by causal connections.
 08:50: ... become emergent properties of the causal propagation of patterns of interactions between timeless, massless ...
 09:04: And what is the nature of these most elementary causal interactions?


20160113: When Time Breaks Down
 01:06: Every tick is the result of countless interactions between the tiniest subatomic elements.
 06:38: ... in an atom, that ticking corresponds to interactions between its component particles and fields, in which the internal parts ...
 06:52: ... rate of these interactions, this ticking, represents the rate at which the atom will change from one ...
 07:03: In a fast moving object, the interactions driving this evolution appears to happen more slowly.


20160106: The True Nature of Matter and Mass
 04:16: ... squared, because the underlying cause is the same the confinement of interactions that themselves travel at the speed of ...
 04:36: Photons in the photon box, but even in the spring, the density wave is ultimately communicated by electromagnetic interactions between the atoms.
 04:46: That itself is a speed of light interaction, even if the resulting density wave isn't.
 07:44: OK, so mass is an emergent property of the interactions of massless particles.


20150624: The Calendar, Australia & White Christmas
 04:40: ... is also slowly spinning down due to its interactions with the moon, so that the mean solar day is getting longer, by about ...


20150520: The Real Meaning of E=mc²
 07:12: For instance, there's the potential energy associated with the interactions of electrons and quarks with the Higgs field.
