
20221019: The Equation That Explains (Nearly) Everything!
 01:02: ... One of the most important founding insights was the idea that the symmetries of nature give rise to the fundamental forces. Gauge invariance says ...
 01:48: ... due to the fact that the universe has this particular rather simple symmetry  which we call a U(1) symmetry. That incredible success led many ...
 02:21: ... symmetries also come from the fact that the wavefunction can be distorted in ...
 04:05: ... motion, but Lagrangian is especially powerful because of how it respects symmetries. If the system that we are studying has a certain symmetry then the ...
 04:36: ... a good idea to figure out the Lagrangian for a wavefunction that has our symmetries of interest. And that is exactly what the Standard Model Lagrangian is. ...
 05:37: ... symmetries I mentioned allow the particles to have two different types of spins. ...
 06:02: ... are called bosons. They transmit energy and momentum according to the symmetries of each force. Some parts of the standard model lagrangian deal with ...
 06:57: ... represented with a capital A, this is the field that preserves the U(1) symmetry of electromagnetism, and the kinetic term for photons is made of the ...
 08:37: ... many indices you see here come from the complex symmetries of SU(3), and account for all the different types of gluon. The bosons ...
 09:45: ... us how fermions are gonna interact with the fields that preserve the symmetries of nature. This is the piece that tells us that matter and forces ...
 10:36: ... charge, isospin, hypercharge, and color charge, and the more complex the symmetry the more indicies you need. Also, next to the charges are the coupling ...


20220824: What Makes The Strong Force Strong?
 13:50: The reason this pattern arises in so many different places is a question of symmetry.
 14:14: ... symmetry is baked into the laws of physics and there it manifests as the Strong ...
 14:27: We have 3 colour receptors, and our brains use the SU(3) symmetry group to combine the input from those receptors into our subjective sense of colour.


20220720: What If We Live in a Superdeterministic Universe?
 15:52: ... that have been chosen arbitrarily in order to break the underlying symmetries of ...
 16:03: Agnibho Dutta asks if there’s any symmetry in physics, which holds for transformations in the color charge?
 16:18: The symmetry in question is the strong force symmetry, known as the Special Unitary Group of order 3, or just SU(3).
 17:56: ... it was a nefarious trick to teach you about hidden conventions and symmetries. ...


20220630: Could We Decode Alien Physics?
 05:33: ... buried deep in the laws of physics is a subtle breaking of charge symmetry. So in order to save the world from poorly assembled alien ...
 07:38: ... a parity inversion. Parity is another fundamental and broken symmetry of nature like charge, and just as with charge ...
 10:41: ... is the symmetry between left and right handed chirality for particles with quantum ...
 11:52: ... final symmetry and the final convention that we need to figure out is how the ...
 13:42: ... powerful. It points to the existence of an underlying symmetry of space ...


20220427: How the Higgs Mechanism Give Things Mass
 01:35: ... the episodes that led to this  fields and forces and symmetries and all that. Similar to how the fabric of a drum has ...
 02:26: We saw in our episode on Noether’s theorem that these symmetries lead to conservation laws.
 03:09: ... one of the fundamental forces arises from a symmetry of nature  in this case the fact that the laws of physics ...
 03:36: ... trick to explain the weak interaction as arising from symmetries. We saw that we could invent a pair of totally abstract degrees ...
 04:08: ... deal breaker actually  massive bosons break gauge symmetries. According to something called Goldstone’s theorem, all gauge ...
 04:37: ... so that they apply at the same time. We call this combined symmetry group U(1)xSU(2). The resulting gauge field still has bosons ...
 05:24: ... defines electric charge. Is it time to give up on this symmetry stuff ...
 05:38: ... clue. I said that massive bosons break the gauge symmetry. But what if that’s okay? We’ve also talked about the idea of ...
 06:43: ... Now the current state of the system has a broken symmetry, even if the symmetry of the landscape ...
 07:01: ... let’s just see if we can break the symmetries of the universe in a similar way. The equivalent of ...
 09:00: ... within this field. This particular Lagrangian has the simple symmetry that it’s the same if you reflect it around the y ...
 09:34: ... would be a global U(1) symmetry. Repeating our electromagnetism trick means requiring ...
 10:50: ... still a symmetric potential  it has the same global U(1) symmetry as the original. But if the universe suddenly transitions ...
 11:02: ... correspond to different physical states. We say that the symmetry is spontaneously broken. The current state of the field ...
 11:28: ... is just like how the field of magnets can be in a state of broken symmetry even though the overall equations of magnetism have not ...
 12:59: ... interactions, so we need simultaneous local U(1) and SU(2) symmetry. Let’s just do U(1) because that gives us the basic picture. ...
 16:02: ... boson 10 years ago verified the idea that the underlying symmetries of nature explain and unify some of the forces of nature. ...


20220323: Where Is The Center of The Universe?
 17:09: When the universe cooled down and the electroweak symmetry was broken, particles were locked in whatever isospin state they happened to be in.


20220316: What If Charge is NOT Fundamental?
 07:27: He recognized that these patterns were actually representations of a mathematical symmetry known as SU(3).
 07:34: ... we can’t get into the gory details of symmetry groups in this episode, but in short, GellMann realized that he ...
 12:43: That event  the breaking of electroweak symmetry  created the weak and electromagnetic forces as we know them today.
 13:24: We’ll find out soon as we continue to unravel the tangled symmetries of spacetime.


20220308: Is the Proxima System Our Best Hope For Another Earth?
 19:27: ... unmeasurable  just the the phase of the wavefunction  it’s a symmetry of the Higgs field and doesn’t affect the behavior of the ...


20220210: The Nature of Space and Time AMA
 00:03: ... that their universe has a certain boundary condition that breaks the symmetry of time uh and that's simply that things were ordered in the past ...


20211110: What If Our Understanding of Gravity Is Wrong?
 16:02: In simple terms, the universe at its very core seems to be a set of symmetries which are manifest in the Lagrangian.
 16:10: ... but we don't know all the symmetries and we are not sure how those symmetries fit with each ...
 16:23: It’s the symmetries of the Lagrangian via Noether’s theorem that yields our conservation laws and ultimately, well, all of physics.


20211005: Why Magnetic Monopoles SHOULD Exist
 03:30: ... a near perfect symmetry between electricity and magnetism which only gets screwed up when you ...
 03:40: You could also have symmetry between these equations if there was such a thing as magnetic charge.
 04:37: ... from requiring that the equations of quantum mechanics had a particular symmetry  the measurements they predict are unaltered by changes in one simple ...
 09:00: We talked about that before  about how the breaking of the symmetry of the Higgs field separated the weak and electromagnetic forces.
 09:16: These involved slightly more complicated symmetry breakings.
 13:48: And so many of us remain obsessed with this elusive beast, and convinced of its inevitability according to the symmetries of space time.


20210921: How Electron Spin Makes Matter Possible
 02:18: ... groups of particles that have two properties: 1) this weird rotational symmetry, and 2) indistinguishability  which is just the fact that all electrons, ...
 14:26: ... are indistinguishable and they obey a simple, if odd, rotational symmetry. Ironically, to prove the structural integrity of matter I had to ...


20210915: Neutron Stars: The Most Extreme Objects in the Universe
 04:39: ... each other, like gridlocked traffic. And the symmetry of that repulsion forces nuclei into a regular grid. In this case ...


20210623: How Quantum Entanglement Creates Entropy
 16:39: ... But we know for sure that this universe has a continuous rotational symmetry  there is no preferred angle. That’s the basis for ...


20210421: The NEW Warp Drive Possibilities
 09:43: That gave them an axial symmetry.


20210210: How Does Gravity Warp the Flow of Time?
 07:22: But as soon as one of those observers changes direction, the symmetry is broken.


20201208: Why Do You Remember The Past But Not The Future?
 07:50: But in the case of the asteroid, time symmetry is much more easily broken.
 13:26: Yossi Sirote asks essentially the same question  doesn't the collapse of the wave function break time symmetry.
 13:33: ... collapse is a random rather than deterministic event, then timereversal symmetry is broken the arrow if time is established by quantum ...


20201118: The Arrow of Time and How to Reverse It
 01:21: ... going to dive into the first part of this  How does entropy break the symmetry of time, and cause the future to differ from the past. We’ll follow with ...
 02:53: ... the relationship between time slices of our block universe. Time has a symmetry in the sense that the past and future aren’t differentiated by the laws ...
 03:12: ... time. So the 2nd law does dictate a direction for time  it breaks the symmetry. To see why, we’ll need to review entropy. We’ve talked about it before, ...
 08:11: ... block universe connected by the laws of physics, then we can break the symmetry in the direction of time if one of those slices has a very unusual ...


20201104: Electroweak Theory and the Origin of the Fundamental Forces
 00:08: But some extremely subtle clues in nature have led us to believe that the forces of nature were once unified, ruled by a single, grand symmetry.
 00:20: And how do the forces of nature arise from mathematical symmetries in the first place?
 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.
 02:56: QED is what we call a gauge theory  its forcecarrying fields and particles arise from the symmetries of the quantum equations of motion.
 04:28: At least assuming that the symmetries of gauge theory remain intact.
 05:42: So there we go  we insisted on a symmetry  that the Schrodinger equation is invariant to changes in the local phase of the wavefunction.
 05:54: So that is gauge theory in a nutshell: it explains a force by imposing symmetries on the equations of motion.
 06:57: ... ‘1’ just means the symmetry transformations act on states which can be completely represented by ...
 07:08: Imposing this U(1) symmetry on our equations of motion led us to something very real and physical  electromagnetism.
 07:14: So it makes sense to see what other symmetries do.
 07:36: ... if we require this transformation to now respect the SU(2) symmetry  for example requiring unitarity  we knock out 5 degrees of freedom ...
 08:08: The fields and corresponding particles produced by the pure symmetries we described are fundamentally massless.
 08:40: The perfect masslessness of these gauge fields and bosons is a direct consequence of the perfect symmetries from which they come.
 08:48: Adding in mass screws up those symmetries.
 09:01: In order for the weak force bosons to have mass, we have to willingly break the symmetry that gave us them in the first place.
 09:16: ... for the equations of motion describing a system to have a particular symmetry  to not care about changes in some property  but at the same time, for ...
 09:53: This represents the symmetry in our equations.
 10:27: This is a state of broken symmetry.
 10:39: We call this spontaneous symmetry breaking.
 10:48: ... the equations of motion respect the symmetries that give us the necessary gauge field, but the physical system  the ...
 11:11: What is this symmetry?
 11:21: It turns out that both the weak force AND electromagnetism come from the breaking of a larger symmetry group.
 11:29: And actually, that larger symmetry group is just the combination of our U(1) and SU(2) symmetries.
 11:36: The combined SU(2)xU(1) symmetry is the electroweak field, and it has 4 massless bosons, like a well behaved symmetry should.
 11:48: ... at low temperatures, this symmetry is spontaneously broken  leaving an independent, massless s(1) field ...
 12:33: We just asked what would happen if the equations of motion governing nature had certain symmetries.
 12:39: The very existence of those symmetries requires a family of fields and particles that we now observe in nature.
 12:47: ... bosons their mass  we have to conclude that really these fields, these symmetries, are ultimately ...
 13:01: ...  the electroweak unification set us on this grand quest to find deeper symmetries that could bring the strong nuclear force into the fold, allowing us to ...
 13:19: ... and the complexity they enable, inevitable consequences of the broken symmetries of ...
 15:07: In the case of the perfect spherical symmetry inside of a Schwarzschild black hole, all geodesics do indeed converge.


20201027: How The Penrose Singularity Theorem Predicts The End of Space Time
 02:48: ... a perfect point. Surely any tiny deviation from spherical symmetry would cause particles to miss each other at the last ...


20200921: Could Life Evolve Inside Stars?
 03:23: ... technical term is “spontaneous symmetry breaking”  the same events that led to the appearance of the separate ...
 06:02: ... example, there’s this scenario in this early universe symmetrybreaking stuff where, after the monopoles form, they split in two  into ...


20200908: The Truth About Beauty in Physics
 04:11: It’s the geometric symmetry of the circle or the platonic solid that seems beautiful.
 04:17: ... in physics, when we talk about symmetry we mean that a physical law is unchanged by some transformation  ...
 04:29: The universe does obey deep, underlying symmetries that are reflected on all scales of complexity.
 04:36: ... make powerful use of these symmetries to derive our laws of physics, and so perhaps it’s not surprising these ...
 10:13: Just add an additional degree of freedom  actually a symmetry  at each point in space and electromagnetism appears, almost miraculously.
 11:30: His idea of introducing a new symmetry to space was translated to adding a new symmetry to the wavefunction in quantum mechanics.
 11:43: ... Weyl’s idea evolved into what we now call gauge symmetry, and it’s the basis for the slightly ugly but fantastically successful ...


20200810: Theory of Everything Controversies: Livestream
 00:00: ... particles and forces have the structure that they do the particular symmetries the particular arrangements of particles are like biologists before ...


20200728: What is a Theory of Everything: Livestream
 00:00: ... is a principle of invariance the idea that there are underlying symmetries in this case symmetries that leave the speed of light um the same ...


20200708: Does Antimatter Explain Why There's Something Rather Than Nothing?
 02:12: ... many physicists think the answer lies in the fundamental symmetries of the universe, or, rather, in the breaking of these symmetries. We’ve ...
 03:13: ... one by one, these presumed symmetries failed. The first to fall was parity, with ChienShiung Wu’s famous ...
 04:05: ... maybe the violation of full CPT symmetry is needed to explain this imbalance. We saw in our previous episode that ...
 04:48: ... of special relativity and the Standard Model are correct, then CPT symmetry must hold. But, we already know that our current understanding of the ...
 07:21: ... regular hydrogen  deviations that could point to the violation of CPT symmetry. ALPHA uses CERN’s proton synchrotron to get their antiprotons. The ...
 11:51: ... means we have a better idea of where to look for this strange BROKEN symmetry that leads to matterantimatter imbalance and to the fact that we have ...


20200428: Space Time Livestream: Ask Matt Anything
 00:00: ... a few hours but if it's something like gauge theory and electroweak symmetry breaking then working hard with the quantum physicist it takes us it ...


20200324: How Black Holes Spin Space Time
 02:56: ... did it take so long? Well, general relativity is hard, and the spherical symmetry in the Schwarzschild solution eliminated a lot of complexity. Without ...


20200211: Are Axions Dark Matter?
 00:03: ... does the strong nuclear force, the fundamental symmetries of nature, and a laundry detergent have in common? Well, they’re all ...
 01:05: ... to go back and look at one of the most powerful concepts in physics: symmetry. We expect the laws of physics to be symmetric with respect to certain ...
 02:35: ... of the strong force, derived with QCD, actually allow violation of CP symmetry. In fact they almost demand it  and yet no such violation has ever been ...
 05:16: ... terms  the ones added by the weird vacuum  that appear to violate CP symmetry. That means the strong force should show CP violation. So why doesn’t it? ...
 06:32: ... the strong CP problem its's that if any of the quarks are massless, CP symmetry is automatically conserved. However, as far as we can tell, none of the ...


20200127: Hacking the Nature of Reality
 07:23: But in order to avoid those sums of Feynman diagrams, Smatrix theory also relies on symmetries between those virtual interactions.
 07:32: In particular something called crossing symmetry.
 07:49: And here’s another example of crossing symmetry.
 09:11: ... based on these global consistency conditions and taking advantage of symmetries is also called a bootstrap model  from expression “pull yourself up by ...


20191007: Black Hole Harmonics
 13:35: You can Learn probabilistic basics, such as fairness, expected value, and symmetry, in their course Probability Fundamentals.


20190410: The Holographic Universe Explained
 06:25: By making this a conformal field theory we’ve added a symmetry –invariance under local changes in scale – also known as Weyl invariance.


20190403: The Edge of an Infinite Universe
 16:39: In fact conservation of energy comes from this symmetry, as revealed by Noether's theorem.


20190124: The Crisis in Cosmology
 13:32: Then we'll get to comments on our CPT symmetry episode.
 15:08: Okay, let's move on to our episode on the ultimate symmetry of nature,...
 15:22: The T in CPT symmetry isn't a literal rewinding of the clock.
 15:36: If the universe has this sort of T symmetry,...
 16:09: TinyFox Tom asks whether mass would be inverted under CPT symmetry.
 17:13: As to the motion reversal symmetry of the T in CPT,...
 17:23: But, at any rate, remember that T symmetry is broken.
 17:27: Both the T of CPT and true time reversal symmetry.


20190116: Our Antimatter, Mirrored, TimeReversed Universe
 00:03: ... foundations of quantum theory rest on its symmetries for example it should be impossible to distinguish our universe from one ...
 02:02: ... behaves differently so what's the big deal well the violation of parity symmetry poses a threat to an even deeper symmetry cpt symmetry the combined ...
 03:02: ... said right to left and send matter to antimatter at first glance this CP symmetry appears to hold not just in an imaginary clocks but also in the ...
 08:43: ... here's the issue if CP symmetry is violated and CPT symmetry holds then T symmetry must also be violated ...
 10:54: ... end up back in its starting configuration. On the other hand broken T symmetry says that if you do this reversal the future won't perfectly mirror the ...


20181220: Why String Theory is Wrong
 00:41: ... very first gauge symmetry  Weyl invariance Einstein pointed out that the proposal led to some ...
 05:30: ... is a theoretical symmetry between bosons and fermions, which very elegantly explains certain ...
 05:47: ... introduction of supersymmetry along with the discovery of the right symmetries for the extra dimensions sparked the first superstring revolution of the ...
 06:32: What differs is the detailed geometries and symmetries of those spaces, and the way strings vibrate within them.
 14:34: ... idea of explaining electromagnetism by adding his gauge symmetry to general relativity was wrong, but it inspired the entire field of ...
 14:48: It also gave us the sought after quantum electromagnetism in the end, just with a slightly different symmetry.


20181212: Quantum Physics in a Mirror Universe
 00:02: ... at a universe whose laws are fundamentally different when we think about symmetry the first thing that comes to mind is mirror symmetry butterflies ...


20181114: Supersymmetric Particle Found?
 01:46: ... a very natural explanation for the discrepancy by introducing a new symmetry between the fermions, which comprise matter, and the bosons, which ...


20181107: Why String Theory is Right
 07:25: A big part of it is making use of symmetries.
 07:28: ... particular coordinates or quantities, we say that that parameter is a symmetry of the system or that the system is invariant to transformations in that ...
 07:42: Finding symmetries can massively reduce the complexity of the math.
 07:46: A really important type of symmetry in quantum mechanics is gauge symmetry.
 07:59: I want to remind you of one particularly crazy result of gauge symmetries.
 08:11: So, we expect the phase of the quantum wave function to be a gauge symmetry of any quantum theory.
 08:54: So in a way, electromagnetism was discovered in its quantum form by studying the symmetries of quantum mechanics.
 09:02: ... turns out that exploring a very different symmetry of string theory both makes it possible to quantize the theory and gives ...
 09:20: Applying the usual old symmetries got physicists some of the way, but to succeed, they needed an extra weird type of symmetry.
 09:29: That symmetry is Weyl symmetry or Weyl invariance.
 09:43: Hermann Weyl actually came up with this symmetry right after Einstein proposed his general theory of relativity.
 09:54: ... story Weyl invented the name gauge symmetry to describe this scale invariance inspired by the gauge of railroad ...
 10:06: Anyway, Weyl symmetry doesn't work.
 10:30: ... the 2D sheet traced out in spacetime by a vibrating 1D string has this symmetry that lets us redefine the scale on its surface however we ...
 11:04: But there's a cost to using this symmetry.


20181025: Will We Ever Find Alien Life?
 13:32: Now, this is a type of gauge symmetry that, in principle, unifies fermions and bosons.
 13:42: Adding the symmetry gives you fermions but it also shaves off dimensions.


20180711: Quantum Invariance & The Origin of The Standard Model
 00:15: But even more stunning is how it was discovered, by peering deep into the symmetries of reality.
 00:38: Previously, we've talked a bit about the symmetries of these equations and how they lead us to conserved quantities like energy and momentum.
 00:49: These symmetries can be portals into entirely new aspects of reality.
 01:47: It's what we call a gauge freedom or a gauge symmetry.
 01:57: But it turns out that these gauge symmetries are an important feature of most of our physical theories describing the universe.
 02:16: A theory that has these gauge symmetries is called a gauge theory.
 02:20: Today, we're going to look at the simplest of the symmetries of the standard model.
 03:29: And this innocuous seeming step introduces a simple symmetry that has profound implications.
 05:02: Global phase is a gauge symmetry of the system.
 05:05: Let's push a little further to see how far this symmetry goes.
 06:26: Local phase is not a gauge symmetry of the basic Schrodinger equation.
 07:52: We just rediscovered electromagnetism by insisting on a gauge symmetry that we had no right to expect to exist in the first place.
 08:12: And now we know how it interacts with particles of matter to give them this symmetry.
 08:40: By the way, applying Noether's theorem tells us there is a conserved quantity associated with any symmetry.
 08:48: In this case, the symmetry is local phase invariance and the conserved quantity is electric charge.
 09:35: To understand those, we'll need to go beyond the Schrodinger equation and to explore new gauge symmetries.
 09:41: It turns out that local phase invariance is just the simplest of the larger suite of gauge symmetries of the standard model.
 09:49: ... symmetries are obtusely named, U1, SU2 and SU3, and they predict the fields that ...
 10:02: ... fields that arise from these gauge symmetries are called gauge fields, and they all have their associated ...
 10:29: ... here is not the nature of the quantum field nor the connection between symmetry and the fundamental forces, perhaps it's the fact that by pure ...


20180523: Why Quantum Information is Never Destroyed
 01:07: And yet, this sort of deterministic symmetry, timereversal symmetry, is essential for information itself to be conserved.
 01:34: ... to discover quantities that are conserved in a system by looking at the symmetries of the equations of ...
 01:49: ... theorem applies to smooth, continuous symmetries where we can transform the chosen coordinate, however much we like, ...
 01:58: But there are also symmetries under discrete transformations.
 02:13: Symmetry in that last one.
 02:14: Timereversal symmetry isn't covered by Noether's theorem, but it's still tied to a conservation law.
 02:57: ... one thing, this timereversal symmetry means complete information about the configuration at all prior times ...
 04:36: It ensures conservation of information and timereversal symmetry because of an even more fundamental rule the conservation of probability.
 06:56: ... how probability works, but the condition also ensures timereversal symmetry and conservation of ...
 11:03: Noether's theorem predicts the conservation laws of physics from the symmetries of nature.


20180516: Noether's Theorem and The Symmetries of Reality
 00:46: They emerge from the fundamental symmetries of nature.
 00:49: The connection between conservation laws and symmetry is encapsulated in Noether's theorem.
 02:08: For every continuous symmetry of the universe, there exists a conserved quantity.
 02:14: First, what do we mean by symmetry?
 02:29: But these are what we call discrete symmetries single flips around one axis or rotation by specific amounts.
 02:36: Noether's theorem applies to continuous symmetries.
 03:17: We have symmetry to spatial translation.
 04:01: Noether's theorem reveals that this time translation symmetry gives us energy conservation.
 04:43: If the very nature of space can change over time, then continuous time symmetry is broken.
 07:15: As long as we can identify that system's symmetries, this is useful in cosmology, but it's also useful in quantum physics.
 07:22: ... general nature of the theorem means we can apply it to not just the symmetries in the dimensions of space and time, but also to more abstract ...
 07:36: Noether's theorem tells us that there should be a corresponding symmetry of nature, and there is.
 07:42: That symmetry is the phase of the quantum field.
 07:54: This symmetry leads to the conservation of electric charge and electric current.
 07:59: This quantum symmetry is just the simplest of a large number of symmetries exhibited by quantum fields, the socalled gauge symmetries.
 08:26: It's founded on the fundamental symmetries of quantum fields.
 08:30: ... going to take a few episodes to explain exactly what these symmetries really are and how they lead to the family of particles and interactions ...
 09:27: ... the fundamental workings of the universe through the continuous symmetries of "Space Time." Thank you to Brilliant for supporting PBS Digital ...


20180228: The Trebuchet Challenge
 02:53: This fact gives us insight into the fundamental symmetries of nature.


20180214: What is Energy?
 09:45: See, the law of conservation of energy arises because of symmetry, in particular time translational symmetry.
 10:00: In fact, for every symmetry in our universe, there exists a conserved quantity.
 10:06: For example, the law of conservation of momentum is due to spatial translation symmetry.
 10:16: ... relationship between conservation laws and symmetries was discovered by mathematician Emmy Noether and Noether's theorem is ...


20171102: The Vacuum Catastrophe
 07:59: ... high vacuum energy or a vacuum energy of exactly 0 if we assume symmetry of positive and negative zero points between different fields, but a ...
 08:28: That sounds like a ridiculously unlikely bit of luck if we can't invoke symmetries.


20170810: The OneElectron Universe
 06:16: In the sense of these fundamental symmetries, antimatter is timereversed matter.


20170707: Feynman's Infinite Quantum Paths
 14:38: It indicates a break in what we once thought to be a fundamental symmetry of the universe.


20170315: Time Crystals!
 02:01: Wilczek came up with a simple model in which charged particles in a superconducting ring break what we call continuous time translational symmetry.
 02:34: ... imaginary system broke this time translational symmetry, because there are global statistical differences in the state of the ...
 03:15: This would break time translational symmetry, which makes most physicists nervous.
 03:23: ... of Tokyo showed from theoretical arguments that time translational symmetry can't be broken by a quantum system in ...
 08:07: ... also add that while their systems do break continuous time translational symmetry, they have a different type of symmetry discrete time ...
 09:15: Before this year, time stood out as a major symmetry that hadn't been broken.


20160316: Why is the Earth Round and the Milky Way Flat?
 00:44: Two key principles, equilibrium and symmetry.
 01:33: And it's the symmetries of the forces at work in creating that equilibrium that decide what that final shape will be.
 01:41: So let's talk about symmetry.
 01:43: ... terms of shape, things like planets and stars have spherical symmetry, meaning you can rotate them in three dimensions and the basic shape ...
 01:53: diskshaped things like galaxies and solar systems have circular symmetry.
 02:04: But how does a force have symmetry?
 02:34: ... gravity has spherical symmetry in the sense that, if you're some distance from a space thing of any ...
 04:56: See, pressure shares that same symmetry as gravity.
 08:36: It's because the effect that prevents their collapse has a very different symmetry.
 10:14: Now, these fundamental symmetries don't just define the shapes of some of the largest things in our universe.
 10:34: Symmetries really do shape the universe on all the scales of space time.


20160106: The True Nature of Matter and Mass
 10:17: Only when the universe cooled down did the Higgs field gain a nonzero value in a phenomenon called spontaneous symmetry breaking.


20151007: The Speed of Light is NOT About Light
 07:05: It's the only one that satisfies all of these pretty fundamental statements about the relativity, symmetry, and consistency of our universe.
 07:40: And honestly, just from the symmetry and relativity arguments that we made, c could be infinity.
