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	2022-12-08: How Are Quasiparticles Different From Particles? 04:51: ... But at the very least quasiparticles make it much easier to model physical processes like semiconductor junctions and in other cases they are ...
	2022-10-26: Why Did Quantum Entanglement Win the Nobel Prize in Physics? 18:49: ... you choose a coordinate system whose dimensions extend  beyond the physical ... 19:28: The equations then work perfectly, which suggest   that the infinities don't belong there  or don't represent anything physical.
	2022-09-28: Why Is 1/137 One of the Greatest Unsolved Problems In Physics? 12:08: If the other constants of nature tie various physical parameters together, perhaps the fine structure constant is what ties those constants together. 12:34: Sure, you could find a combo where the units  cancel out - but that combo wouldn’t necessarily have physical significance. 12:43: ... structure constant also represents the relationship between many real, physical aspects of the universe, seems to be telling us ... 13:15: ... it could be that the fine structure constant is not a physical constant, but a mathematical one, like pi, but perhaps we haven't ... 12:43: ... structure constant also represents the relationship between many real, physical aspects of the universe, seems to be telling us ... 13:15: ... it could be that the fine structure constant is not a physical constant, but a mathematical one, like pi, but perhaps we haven't realized this is ... 12:08: If the other constants of nature tie various physical parameters together, perhaps the fine structure constant is what ties those constants together. 12:34: Sure, you could find a combo where the units  cancel out - but that combo wouldn’t necessarily have physical significance.
	2022-09-21: Science of the James Webb Telescope Explained! 17:35: In reality we physicists are all just playing around with the small, special-case questions about “physical” reality.
	2022-08-17: What If Dark Energy is a New Quantum Field? 00:36: ... mainstream physical explanation for dark energy is that the vacuum of space has a constant ... 05:18: ... if evidence is pointing to omega=-1, and we have a plausible physical explanation for omega=-1, why should we spend youtube episodes and ... 00:36: ... mainstream physical explanation for dark energy is that the vacuum of space has a constant energy ... 05:18: ... if evidence is pointing to omega=-1, and we have a plausible physical explanation for omega=-1, why should we spend youtube episodes and embarrassingly ...
	2022-08-03: What Happens Inside a Proton? 09:50: ... path integral, but instead of trajectories   through physical space we add up trajectories through the space of field ...
	2022-07-27: How Many States Of Matter Are There? 12:38: ... concept is incredibly useful for helping us understand the behavior of physical systems - from the instant after the big bang to the behavior of crowds, ...
	2022-07-20: What If We Live in a Superdeterministic Universe? 00:39: It’s almost as though the physical properties of the objects don’t reside in the objects themselves, but emerge as a consequence of our observations. 05:34: ... that each electron had to carry all the information about its own physical state, in a way that was somehow hidden from the wavefunction of ... 14:22: But think about it this way - your mind has a physical substrate: your brain. 14:30: ... your choices have a physical, even deterministic, substrate - that doesn’t change the fact that right ... 00:39: It’s almost as though the physical properties of the objects don’t reside in the objects themselves, but emerge as a consequence of our observations. 05:34: ... that each electron had to carry all the information about its own physical state, in a way that was somehow hidden from the wavefunction of standard ... 14:22: But think about it this way - your mind has a physical substrate: your brain.
	2022-06-22: Is Interstellar Travel Impossible? 15:52: ... adopt a view that we will call model-dependent realism: the idea that a physical theory or world picture is a model and a set of rules that connect the ...
	2022-06-15: Can Wormholes Solve The Black Hole Information Paradox? 12:40: ... information can escape from the black hole. But what’s the real physical picture here? Well,   no one really has any idea. More ...
	2022-06-01: What If Physics IS NOT Describing Reality? 01:41: ... really the most fundamental thing, and it   gives rise to the physical - a notion he pithily  summarized with the expression “it from ... 02:44: ... fields and particles are,   this still feels like a very physical way  to define the building blocks of ... 03:22: ... mechanics   in which the world is broken up not into  physical parts, but into informational parts.   But what does it mean ... 04:56: ... to a single   binary question seems to give a meaningful  “physical” answer. Consider quantum spin.   From a physical point of ... 01:41: ... really the most fundamental thing, and it   gives rise to the physical - a notion he pithily  summarized with the expression “it from ... 04:56: ... to a single   binary question seems to give a meaningful  “physical” answer. Consider quantum spin.   From a physical point of view, think ... 03:22: ... mechanics   in which the world is broken up not into  physical parts, but into informational parts.   But what does it mean to use ... 04:56: ... “physical” answer. Consider quantum spin.   From a physical point of view, think of it as  a particle’s orientation - a spin axis ... 02:44: ... fields and particles are,   this still feels like a very physical way  to define the building blocks of ... 11:24: ... and supporters would say that the wavefunction does not have a physical   existence independent of the observer. Rather,  the wavefunction ...
	2022-05-04: Space DOES NOT Expand Everywhere 03:48: ... is getting bigger. But what does that mean beyond the math? What’s physically ...
	2022-04-27: How the Higgs Mechanism Give Things Mass 11:02: ... different points around this valley  correspond to different physical states.  We say that the symmetry is spontaneously  broken. ... 12:26: ... because location around that valley represents  a real physical difference in the field ... 11:02: ... different points around this valley  correspond to different physical states.  We say that the symmetry is spontaneously  broken. The current ...
	2022-04-20: Does the Universe Create Itself? 00:30: ... detached observer of the world, capable of monitoring and modeling physical reality without ever disturbing ... 00:59: ... through the act of measurement. Others were desperate to maintain a physical and realist universe, including Albert Einstein himself. We’ve talked ... 01:59: ... in some way creates reality. Others found schemes by which a real, physical universe could be interpreted in the behavior of the wavefunction, such ... 00:59: ... interpretations which say that the universe exists not so much in physical particles and quantum fields, nor solely in the mind of the observer, but rather ... 00:30: ... detached observer of the world, capable of monitoring and modeling physical reality without ever disturbing ... 01:59: ... in some way creates reality. Others found schemes by which a real, physical universe could be interpreted in the behavior of the wavefunction, such as de ... 00:59: ... influence the thing being measured, but it seems we can’t even assign physicality to the world between measurements. As Niels Bohr put it “no phenomenon ...
	2022-03-08: Is the Proxima System Our Best Hope For Another Earth? 16:39: ... collapse theories, where wavefunction collapse is explained as a real, physical ...
	2022-02-16: Is The Wave Function The Building Block of Reality? 03:24: ... function. The wave function may collapse, but particles maintain a rigid physical ... 04:36: ... objective collapse theories, wave functions are real, physical entities that literally collapse when they’re measured. But the collapse ... 03:24: ... function. The wave function may collapse, but particles maintain a rigid physical nature. ...
	2022-02-10: The Nature of Space and Time AMA 00:03: ... don't like to think about the expansion of the universe as of objects physically moving through space away from each other um because that would imply ...
	2021-12-10: 2021 End of Year AMA! 00:02: ... take these stories too seriously um and we can't set you know these physical interpretations we we always use to take with a grain of salt there ...
	2021-11-10: What If Our Understanding of Gravity Is Wrong? 04:41: So MOND would need to do away with the need  for physical dark matter in the other places we see evidence for dark matter. 05:38: ... the fact that you still need some type of physical dark matter in clusters is seen as a strong point against MOND in its ... 04:41: So MOND would need to do away with the need  for physical dark matter in the other places we see evidence for dark matter. 05:38: ... the fact that you still need some type of physical dark matter in clusters is seen as a strong point against MOND in its first ... 04:41: So MOND would need to do away with the need  for physical dark matter in the other places we see evidence for dark matter. 05:38: ... the fact that you still need some type of physical dark matter in clusters is seen as a strong point against MOND in its first ...
	2021-11-02: Is ACTION The Most Fundamental Property in Physics? 17:24: ... to narrow down the space of all possible functions that might represent physical laws into the subset of functions that are consistent with the ...
	2021-10-20: Will Constructor Theory REWRITE Physics? 03:22: ... a universal computer - it’s a system that can perform any computation OR physical task, including creating a copy of ... 07:21: ... cobble them together into chains of deductive reasoning to carve out our physical laws - they are the sculpture that’s left after we carve off all the ... 11:04: ... counterfactuals - of what is possible and what is impossible within this physical space ... 07:21: ... cobble them together into chains of deductive reasoning to carve out our physical laws - they are the sculpture that’s left after we carve off all the “can’ts” ... 11:04: ... counterfactuals - of what is possible and what is impossible within this physical space ... 03:22: ... a universal computer - it’s a system that can perform any computation OR physical task, including creating a copy of ...
	2021-10-13: New Results in Quantum Tunneling vs. The Speed of Light 05:09: ... enough barrier, this ‘Hartman effect’ can effectively teleport real, physical matter between locations faster than it would take to travel that ... 10:35: For a real, physical experiment, we need a clock that’s physically measurable. 05:09: ... enough barrier, this ‘Hartman effect’ can effectively teleport real, physical matter between locations faster than it would take to travel that distance sans ... 10:35: For a real, physical experiment, we need a clock that’s physically measurable.
	2021-10-05: Why Magnetic Monopoles SHOULD Exist 03:54: ... not forbidden is compulsory." meaning that if the math of our physical theory allows it, then it exists in ... 10:05: ... internal arrow that points in a particular direction - not pointing in physical space, but in the space of those 3 degrees of ... 16:16: Still, it would be nice to have a physical picture of spin that doesn’t involve me taking off my belt. 10:05: ... internal arrow that points in a particular direction - not pointing in physical space, but in the space of those 3 degrees of ... 03:54: ... not forbidden is compulsory." meaning that if the math of our physical theory allows it, then it exists in ...
	2021-08-18: How Vacuum Decay Would Destroy The Universe 02:18: ... energy if you want to deform the rubber ring.   Another nice physical analogy is a ball rolling in a dip. The ball will roll up and ...
	2021-08-10: How to Communicate Across the Quantum Multiverse 02:56: ... that - it’s a story about what's really happening behind the math - what “physical” mechanisms give rise to the equations of quantum mechanics. And the fact ... 06:09: ... in the physical world the superposition principle only holds to a point. Real pond ... 07:14: ... normal linear observables are things like position, momentum, spin - the physical stuff that makes up our world. Extra observables would be non-local - ... 02:56: ... that - it’s a story about what's really happening behind the math - what “physical” mechanisms give rise to the equations of quantum mechanics. And the fact is, every ... 07:14: ... normal linear observables are things like position, momentum, spin - the physical stuff that makes up our world. Extra observables would be non-local - they ...
	2021-07-13: Where Are The Worlds In Many Worlds? 09:25: ... match in many ways - including physical location, but there are subtle differences - on one branch a collection ...
	2021-07-07: Electrons DO NOT Spin 11:26: Some physicists think that spin is  more physical than this. Han Ohanian,   author of one of the most used quantum textbooks.
	2021-06-23: How Quantum Entanglement Creates Entropy 13:09: ... us to a picture of reality   that is more informational than physical.  But that information won't stay hidden for   long - only until ...
	2021-04-21: The NEW Warp Drive Possibilities 06:44: We’ll start with the paper entitled Introducing Physical Warp Drives by Alexey Bobrick and Gianni Martire. 03:54: The Alcubierre warp field may be a valid solution to the Einstein field equations, but that doesn’t mean it’s physically possible. 04:01: ... to solve these equations we input a physically possible distribution of mass, energy, on the right side and it spits ... 04:31: ... that are meant to restrict the allowable energy distributions to what is physically possible Alcubierre’s field breaks all of these energy conditions, and ...
	2021-04-13: What If Dark Matter Is Just Black Holes? 02:02: In other words, most of the physical universe needs to be vast swarms of black holes that outweigh all the atoms in the universe by a factor of four.
	2021-03-23: Zeno's Paradox & The Quantum Zeno Effect 08:29: ... of measurement that causes the quantum Zeno effect, but rather it’s a physical consequence of interacting with the ...
	2021-03-16: The NEW Crisis in Cosmology 14:47: ... what does this mean physically? Does it mean anything physically? That's less clear,   ...
	2021-03-09: How Does Gravity Affect Light? 06:00: ... the case of gravitational redshift, we could come up with a physical explanation for the prediction - the difference in the flow of time ... 12:25: We come up with our “physical explanations” and then find that seemingly contradictory explanations work just as well. 06:00: ... the case of gravitational redshift, we could come up with a physical explanation for the prediction - the difference in the flow of time changes the ... 12:25: We come up with our “physical explanations” and then find that seemingly contradictory explanations work just as well.
	2020-12-22: Navigating with Quantum Entanglement 10:27: Earlier this year, Peter Hore, a physical chemist at Oxford co-authored a paper that seems to answer that.
	2020-11-04: Electroweak Theory and the Origin of the Fundamental Forces 05:18: ... change it however you like at any point in space and still get the same physical ... 07:08: Imposing this U(1) symmetry on our equations of motion led us to something very real and physical - electromagnetism. 10:48: ... respect the symmetries that give us the necessary gauge field, but the physical system - the field itself - evolves into a state which no longer ... 07:08: Imposing this U(1) symmetry on our equations of motion led us to something very real and physical - electromagnetism. 05:18: ... change it however you like at any point in space and still get the same physical observables. ...
	2020-10-27: How The Penrose Singularity Theorem Predicts The End of Space Time 03:38: ... paper is   deceptively short - just a couple of pages in Physical Review Letters   However that brevity is deceptive. But ...
	2020-10-20: Is The Future Predetermined By Quantum Mechanics? 02:46: According to quantum mechanics, physical systems, parts of the universe evolve as wave functions. 03:04: The wave function can be thought of as a state in which all physically possible realities intermingle.
	2020-10-13: Do the Past and Future Exist? 00:22: ... into the nature of time - and down that rabbit hole we’ll encounter the physical origin of time, the question of determinism, and even what this tells us ...
	2020-09-21: Could Life Evolve Inside Stars? 12:50: ... driven by the simple intuitions of the likes of Einstein and Dirac that physical law should be mathematically ...
	2020-09-08: The Truth About Beauty in Physics 04:17: ... in physics, when we talk about symmetry we mean that a physical law is unchanged by some transformation - whether shifts in time, space, ... 04:47: ... beautiful if it reduces to a compact expression - a small number of physical properties linked in a mathematically simple ... 07:38: But if a physical law is mathematically ugly, then you can be sure it’s wrong, experiment or no. 09:09: The equations of physical law are beautiful if you get out more than you put in. 04:17: ... in physics, when we talk about symmetry we mean that a physical law is unchanged by some transformation - whether shifts in time, space, ... 07:38: But if a physical law is mathematically ugly, then you can be sure it’s wrong, experiment or no. 09:09: The equations of physical law are beautiful if you get out more than you put in. 04:47: ... beautiful if it reduces to a compact expression - a small number of physical properties linked in a mathematically simple ...
	2020-07-28: What is a Theory of Everything: Livestream 00:00: ... to define what an observer is or talk about that or try to make a physical model of it you know no wonder we're stuck unifying these these ...
	2020-06-30: Dissolving an Event Horizon 06:58: ... being stripped of its event horizon - but it doesn’t tell us the physical ...
	2020-06-22: Building Black Holes in a Lab 01:29: ... I don’t mean old fashioned clockwork black holes - I mean analogies. Physical systems that aren’t black holes but that behave in similar ways - and ... 01:54: ... radiation, which we’ve talked about before. Now Bill Unruh did work with physical analog black holes, but the first analogy started with a pure thought ... 12:23: ... control - real black holes in the lab, the black hole analog is the best physical experiment we can ... 01:54: ... radiation, which we’ve talked about before. Now Bill Unruh did work with physical analog black holes, but the first analogy started with a pure thought ... 12:23: ... control - real black holes in the lab, the black hole analog is the best physical experiment we can ... 01:29: ... I don’t mean old fashioned clockwork black holes - I mean analogies. Physical systems that aren’t black holes but that behave in similar ways - and may reveal ...
	2020-05-27: Does Gravity Require Extra Dimensions? 14:56: But really, the math is just fine - the problem is assigning physical reality after pushing the math too far. 15:44: ... of universes or a time machine indicate that the math may have led our physical understanding astray, and that's even more true when we see that the ... 14:56: But really, the math is just fine - the problem is assigning physical reality after pushing the math too far. 15:44: ... of universes or a time machine indicate that the math may have led our physical understanding astray, and that's even more true when we see that the universe seems to ...
	2020-05-11: How Luminiferous Aether Led to Relativity 00:00: ... pretty satisfied with the state of their science. The great edifice of physical theory seemed complete. A few minor experiments remained to verify ... 01:34: ... of light. In Aristotle’s cosmology, earth, air, fire and water are the physical elements of the world, while aether is the immutable and indestructible ... 00:00: ... pretty satisfied with the state of their science. The great edifice of physical theory seemed complete. A few minor experiments remained to verify everything. ...
	2020-04-28: Space Time Livestream: Ask Matt Anything 00:00: ... we cannot get any deep understanding of the laws that govern the physical world without entering the world of mathematics blah blah blah ...
	2020-04-22: Will Wormholes Allow Fast Interstellar Travel? 09:17: ... and energy in Einstein’s equation in order for those equations to make physical sense. But these energy conditions are more guidelines than rules, and ... 09:44: ... the positive energy density of the mass of the plates themselves for any physically possible ...
	2020-03-31: What’s On The Other Side Of A Black Hole? 03:46: ... becomes is also a 45 degree line, even though it actually has a constant physical ...
	2020-03-24: How Black Holes Spin Space Time 03:54: ... rotating in a Kerr black hole. It’s tempting to just say that some physical thing deep beneath the event horizon is rotating. But if nothing can ...
	2020-02-18: Does Consciousness Influence Quantum Mechanics? 02:40: ... by saying that the electron does NOT travel as a particle or as a physical wave along one of these ... 03:05: The Copenhagen interpretation states that, prior to measurement, it’s meaningless to talk about a real, physical state for the electron. 07:26: They think you’re crazy - they tell you the wavefunction collapsed as soon as the physical experiment was completed. 08:40: Even Erwin Schrodinger, in his 1958 lectures Mind and Matter states that consciousness is needed to make physical reality meaningful. 07:26: They think you’re crazy - they tell you the wavefunction collapsed as soon as the physical experiment was completed. 08:40: Even Erwin Schrodinger, in his 1958 lectures Mind and Matter states that consciousness is needed to make physical reality meaningful. 03:05: The Copenhagen interpretation states that, prior to measurement, it’s meaningless to talk about a real, physical state for the electron. 02:40: ... by saying that the electron does NOT travel as a particle or as a physical wave along one of these ...
	2020-02-11: Are Axions Dark Matter? 01:05: ... certain properties of the universe. If the equations describing a given physical process do not change when you transform a particular property of the ... 04:33: ... to describe what theta actually signifies - in fact there are different physical interpretations - but one way to describe it is that it’s a phase offset ... 01:05: ... certain properties of the universe. If the equations describing a given physical process do not change when you transform a particular property of the universe, ...
	2020-02-03: Are there Infinite Versions of You? 10:59: ... very uncomfortable allowing infinities into any models describing the physical universe - and their intuition shouldn’t be entirely ...
	2020-01-27: Hacking the Nature of Reality 01:41: ... it may be meaningless to even talk about those details as real, physical ... 11:24: Other physicists quickly realised that it was telling us that mesons could be described by a very particular type physical system: a vibrating string. 01:41: ... it may be meaningless to even talk about those details as real, physical events. ... 10:33: And as we discussed in our episode on virtual particles, the physical-ness of these states are questionable at best.
	2020-01-06: How To Detect a Neutrino 08:14: ... ♪ ♪ but one possibility is 'leptogenesis': ♪ ♪ a hypothetical physical process that may have occurred right after the Big ... 08:22: ♪ (𝘴𝘭𝘰𝘸𝘭𝘺 𝘧𝘢𝘥𝘦 𝘰𝘶𝘵) ♪ a hypothetical physical process that may have occurred right after the Big Bang. 08:14: ... ♪ ♪ but one possibility is 'leptogenesis': ♪ ♪ a hypothetical physical process that may have occurred right after the Big ... 08:22: ♪ (𝘴𝘭𝘰𝘸𝘭𝘺 𝘧𝘢𝘥𝘦 𝘰𝘶𝘵) ♪ a hypothetical physical process that may have occurred right after the Big Bang.
	2019-11-18: Can You Observe a Typical Universe? 15:59: ... just as easy to imagine a physical principle that gives you only one universe with an unavoidable ...
	2019-11-04: Why We Might Be Alone in the Universe 12:39: The strings of string theory have a somewhat physical interpretation - the fact that they can hold energy and vibrate and exist in space. 12:48: But the loops of LQG aren't really physical at all. 13:17: But that doesn't mean the loops are physical, they're just a way to parameterize the quantum-scale geometry of space. 13:24: Where we transition from the abstract to the physical is not at all clear, and, honestly, hurts my head. 12:39: The strings of string theory have a somewhat physical interpretation - the fact that they can hold energy and vibrate and exist in space.
	2019-09-30: How Many Universes Are There? 16:16: ... the orbit" doesn't necessarily reflect a fundamental difference in the physical nature and formation process of the ...
	2019-09-23: Is Pluto a Planet? 00:48: Biologists group organisms by similar physical characteristics, and this taxonomy reflects genetic relationships.
	2019-08-19: What Happened Before the Big Bang? 07:35: ... with giant fluctuations as likely to occur as tiny ones and all physical sizes in between, and that is exactly what we see in the ... 12:29: ... actually gives a physical reason for the universe to have started with a rapid outward expansion ... 07:35: ... with giant fluctuations as likely to occur as tiny ones and all physical sizes in between, and that is exactly what we see in the ...
	2019-07-18: Did Time Start at the Big Bang? 08:14: ... It's wrong Any time you encounter a singularity in the mathematics of a physical theory you have good reason for skepticism It's probably telling you ...
	2019-07-15: The Quantum Internet 00:21: ... longer are economies and industries are solely characterized by the physical goods they produce, and in fact some of the largest companies in the ... 10:07: There are also proposals for removing the need for physical storage all together, with repeaters that are entirely photonic. 00:21: ... longer are economies and industries are solely characterized by the physical goods they produce, and in fact some of the largest companies in the world ... 10:07: There are also proposals for removing the need for physical storage all together, with repeaters that are entirely photonic.
	2019-04-24: No Dark Matter = Proof of Dark Matter? 00:03: ... to keep up with the mounting evidence that dark matter looks like actual physical stuff but still we have an impasse astronomers and particle physicists ...
	2019-04-10: The Holographic Universe Explained 09:19: A duality is when two seemingly different theories prove to represent the same underlying physical reality.
	2019-04-03: The Edge of an Infinite Universe 02:00: ... just useful for doing calculations in physics, but may be as real as the physical universe it ...
	2019-03-28: Could the Universe End by Tearing Apart Every Atom? 11:54: ... there's a plausible physical explanation for a constant dark energy that the vacuum has a set amount ...
	2019-02-20: Secrets of the Cosmic Microwave Background 07:42: ... size of a spot and use simple geometry and that gives us the exact physical size that we expect from our theory from our standard ruler then that's ...
	2019-01-24: The Crisis in Cosmology 16:47: But it's not so obvious whether this idea corresponds to anything physical.
	2019-01-16: Our Antimatter, Mirrored, Time-Reversed Universe 00:42: ... direction so with that spin axis which is fundamentally different physical behavior. So, what does this have to do with Feynman's clock? well, he ... 10:54: ... accurately thought of as flipping the direction of the evolution of a physical system - an explosion becomes an implosion and particle decay becomes ... 00:42: ... direction so with that spin axis which is fundamentally different physical behavior. So, what does this have to do with Feynman's clock? well, he proposes a ...
	2019-01-09: Are Dark Matter And Dark Energy The Same? 07:43: But that’s cool – the physical justification behind dark energy is pretty tenuous too.
	2018-12-20: Why String Theory is Wrong 00:07: There's this idea that beauty is a powerful guide to truth in the mathematics of physical theory. 07:04: A duality in physics is when two apparently different mathematical theories proved to represent the same physical process. 00:07: There's this idea that beauty is a powerful guide to truth in the mathematics of physical theory.
	2018-11-14: Supersymmetric Particle Found? 14:42: A 2D world sheet has to be traced by a 1D physical object.
	2018-10-31: Are Virtual Particles A New Layer of Reality? 05:42: It's because they aren't physical. 08:12: But even that description is way too physical and Australian. 12:45: If they represent a physical reality, then there should be no way to do quantum field theory calculations without them.
	2018-10-18: What are the Strings in String Theory? 00:59: We need to use physical measurement to fix 19 free parameters like the masses of particles. 08:05: The strings are real physical strands, and the waves are wiggles in actual space. 08:11: But physical strands of what? 00:59: We need to use physical measurement to fix 19 free parameters like the masses of particles. 08:05: The strings are real physical strands, and the waves are wiggles in actual space. 08:11: But physical strands of what?
	2018-10-10: Computing a Universe Simulation 00:32: ... if this is the prime, the original, physical universe, rather than somewhere deep in the simulation nest, we can ... 01:04: ... particles, atoms, and ultimately to all of the emergent laws of physics, physical structure, and ultimately the ... 01:48: ... we aren't emergent patterns of a cellular automaton, we can think of any physical reality as a computation, so long as it's underlying mechanics are ... 01:04: ... particles, atoms, and ultimately to all of the emergent laws of physics, physical structure, and ultimately the ... 00:32: ... if this is the prime, the original, physical universe, rather than somewhere deep in the simulation nest, we can still think of ...
	2018-10-03: How to Detect Extra Dimensions 14:02: Renormalization resets the scale to something finite by measuring one or more actual physical properties of the system.
	2018-09-20: Quantum Gravity and the Hardest Problem in Physics 10:23: They can be brought back to reality by actual physical measurements of a few simple numbers in a process called renormalization.
	2018-08-15: Quantum Theory's Most Incredible Prediction 10:34: However, the ultimate arbiter of any physical theory is experiment.
	2018-08-01: How Close To The Sun Can Humanity Get? 10:42: ... represents some physical system that can detect incoming particles, measure their velocity, and ... 13:36: Remember, Maxwell's demon is just a metaphor for many potential types of physical gate.
	2018-07-25: Reversing Entropy with Maxwell's Demon 07:58: That's a physical process that reduces the demon's internal entropy, and that takes an irreversible transfer of energy.
	2018-07-18: The Misunderstood Nature of Entropy 00:54: ... that "the thermodynamics that encapsulates the second law is the only physical theory of universal content which I am convinced will never be ... 03:35: ... the days when many, including Carnot himself, believed that heat was a physical fluid called ... 00:54: ... that "the thermodynamics that encapsulates the second law is the only physical theory of universal content which I am convinced will never be overthrown." And ...
	2018-07-11: Quantum Invariance & The Origin of The Standard Model 00:03: ... standard model of particle physics is the most successful, most accurate physical theory ever developed, describing with stunning accuracy the fundamental ... 01:57: But it turns out that these gauge symmetries are an important feature of most of our physical theories describing the universe. 02:35: ... mathematical object that contains all the information about a particular physical ... 02:49: The best we can do is make a measurement of physical observables, like position or momentum. 10:29: ... than our capacity for intuition, we are led to true discoveries about physical ... 10:49: And following those mathematical labyrinths reveals physical theory with stunning predictive power, like the standard model of particle physics. 11:42: It could mean there's some other physical process that we don't understand yet. 02:49: The best we can do is make a measurement of physical observables, like position or momentum. 11:42: It could mean there's some other physical process that we don't understand yet. 10:29: ... than our capacity for intuition, we are led to true discoveries about physical reality. ... 01:57: But it turns out that these gauge symmetries are an important feature of most of our physical theories describing the universe. 00:03: ... standard model of particle physics is the most successful, most accurate physical theory ever developed, describing with stunning accuracy the fundamental ... 10:49: And following those mathematical labyrinths reveals physical theory with stunning predictive power, like the standard model of particle physics.
	2018-07-04: Will A New Neutrino Change The Standard Model? 03:39: The physical interpretation of chirality is pretty abstract. 04:01: However, the physical interpretation is much more abstract. 03:39: The physical interpretation of chirality is pretty abstract. 04:01: However, the physical interpretation is much more abstract.
	2018-05-09: How Gaia Changed Astronomy Forever 02:15: Knowing the distance to a star is critical for determining its other physical properties.
	2018-04-18: Using Stars to See Gravitational Waves 06:50: Gravitational radiation should have physical effects as shown by the sticky bead argument first presented by Richard Feynman. 05:28: That's beyond any gravitational wave interferometer that we could ever physically construct.
	2018-03-15: Hawking Radiation 06:38: The physical interpretation of this mixing via the Bogoliubov transformations is tricky.
	2018-02-14: What is Energy? 09:34: ... being a powerful accounting tool for describing the behavior of the physical universe, it's also a hint, a hint of something more ...
	2017-10-04: When Quasars Collide STJC 12:12: The alternative is that many universes or patches of universe exist that encompassed an extremely wide range of physical states.
	2017-09-28: Are the Fundamental Constants Changing? 03:05: In fact, it may be impossible to interpret changes in any physical constant that has units.
	2017-07-07: Feynman's Infinite Quantum Paths 08:56: It's not just that a particle can travel infinite physical paths.
	2017-06-28: The First Quantum Field Theory 05:52: It follows the changing position and momentum and generally the physical quantum state of every individual particle but that's extremely inefficient. 07:12: Instead of quantizing particles' physical properties like position and momentum, as did Schrodinger, Dirac quantized the electromagnetic field itself. 05:52: It follows the changing position and momentum and generally the physical quantum state of every individual particle but that's extremely inefficient.
	2017-06-21: Anti-Matter and Quantum Relativity 15:15: ... book that provides a lot of real crunch, but also really delves into the physical implications and the true meaning of the ... 15:28: ... Richard Feynman's "The Character of Physical Law." And one of Feynman's greatest talents was his uncanny ability to ... 15:15: ... book that provides a lot of real crunch, but also really delves into the physical implications and the true meaning of the ... 15:28: ... Richard Feynman's "The Character of Physical Law." And one of Feynman's greatest talents was his uncanny ability to see the ...
	2017-05-31: The Fate of the First Stars 12:34: It may be that physical environment is no longer as strong a force in driving natural selection.
	2017-05-17: Martian Evolution 09:49: This has led to an incredible variety of physical appearance.
	2017-05-03: Are We Living in an Ancestor Simulation? ft. Neil deGrasse Tyson 02:31: Well, 30 years, whatever it was, would potentially be physical.
	2017-03-15: Time Crystals! 00:41: ... physical review letters, entitled "Discreet Time Crystals: Rigidity, Criticality, ...
	2017-01-19: The Phantom Singularity 03:29: ... the movement of water to human population growth, mathematics predicts a physical singularity, and we've been forced to reject the corresponding ... 10:11: It's nothing physical. 03:29: ... the movement of water to human population growth, mathematics predicts a physical singularity, and we've been forced to reject the corresponding ... 10:55: Anyway the upshot is that it's really a breeze to drop through the event horizon, both physically and mathematically.
	2017-01-11: The EM Drive: Fact or Fantasy? 12:12: It's certainly possible that we're missing some amazing physical phenomenon that will make electromagnetic communication redundant.
	2016-12-08: What Happens at the Event Horizon? 17:42: ... from his 1956 book, he, Bohm, assumes that the [INAUDIBLE] wave is a physical reality, even the [INAUDIBLE] wave in configuration ... 01:38: For example, are objects falling through the event horizon really physically frozen there from the point of view of the outside universe?
	2016-11-30: Pilot Wave Theory and Quantum Realism 01:19: But there is one interpretation of quantum mechanics that remains comfortably, almost stodgily, physical. 01:47: Pilot-wave theory is perhaps the most solidly physical, even mundane, of the complete and self-consistent interpretations of quantum mechanics. 02:27: One aspect of that radical thinking was that the wave function is not a wave in anything physical but an abstract distribution of probabilities. 11:55: ... to have a consistent interpretation of quantum mechanics that is both physical and deterministic, no hoo-ha ...
	2016-09-21: Quantum Entanglement and the Great Bohr-Einstein Debate 00:00: [MUSIC PLAYING] Is there a hidden physical reality that underlies the strange behavior of the quantum world? 02:35: There must exist what we call hidden variables that reflect a more physical underlying reality. 04:17: ... thought that every special point in the universe must be real and physical and defined by knowable quantities, local hidden variables that could ... 00:00: [MUSIC PLAYING] Is there a hidden physical reality that underlies the strange behavior of the quantum world? 02:35: There must exist what we call hidden variables that reflect a more physical underlying reality.
	2016-08-10: 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. 08:27: ... contrast, a physical interpretation of the wave function, like the De Broglie-Bohm Pilot Wave ... 08:44: That's a bit uncomfortable, because to explain experimental results, those physical properties need to act and change instantly at any distance. 08:57: Now the delayed choice quantum eraser double slit experiment doesn't tell us whether the wave function is physical or not. 09:04: ... of the wave function, is no less well, crazy-sounding than a physical ... 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. 08:27: ... contrast, a physical interpretation of the wave function, like the De Broglie-Bohm Pilot Wave Theory, ... 09:04: ... of the wave function, is no less well, crazy-sounding than a physical interpretation. ... 08:44: That's a bit uncomfortable, because to explain experimental results, those physical properties need to act and change instantly at any distance. 08:27: ... like the De Broglie-Bohm Pilot Wave Theory, requires an underlying physicality, a set of defined properties that evolves with the wave ... 09:33: So perhaps they can even affect coherence and decoherence retroactively and physically without making a causal mess.
	2016-07-27: The Quantum Experiment that Broke Reality 00:13: It's one of the most stunning illustrations of how the quantum world is very, very different from the large-scale world of our physical intuition. 00:22: In fact, it hints that the fundamental nature of reality may not be physical at all, at least in any sense that we're familiar with. 07:59: The Copenhagen interpretation says that the wave function doesn't have a physical nature. 09:49: There are interpretations that give the wave function a physical reality. 10:06: This may give us a more physical medium that drives these waves of possibility. 00:13: It's one of the most stunning illustrations of how the quantum world is very, very different from the large-scale world of our physical intuition. 10:06: This may give us a more physical medium that drives these waves of possibility. 07:59: The Copenhagen interpretation says that the wave function doesn't have a physical nature. 09:49: There are interpretations that give the wave function a physical reality.
	2016-07-20: The Future of Gravitational Waves 06:57: And the extra credit question asked, what physical distance does the particle actually tunnel?
	2016-06-15: The Strange Universe of Gravitational Lensing 11:28: The idea is that a physical system doesn't have the familiar classical properties like position, momentum, spin, et cetera, until it is observed. 11:45: ... deterministic in that in order for the wave function to become a set of physical properties, there needs to be a completely random sampling of its ... 12:16: The wave function that we calculate defines the probability that we will observe a particular set of physical properties. 12:39: ... something to it that collapses its wave function into the classical physical properties like position and ... 11:45: ... deterministic in that in order for the wave function to become a set of physical properties, there needs to be a completely random sampling of its probability ... 12:16: The wave function that we calculate defines the probability that we will observe a particular set of physical properties. 12:39: ... something to it that collapses its wave function into the classical physical properties like position and ...
	2016-05-18: Anti-gravity and the True Nature of Dark Energy 02:31: But what physical thing about dark energy is producing this outward push, this anti-gravity? 07:00: Dark energy is real physical stuff. 07:03: And that means its anti-gravity effect must come from its physical properties. 10:35: That looks like negative pressure, and yet this abstract-sounding negative pressure has a very real physical effect. 07:03: And that means its anti-gravity effect must come from its physical properties. 07:00: Dark energy is real physical stuff. 02:31: But what physical thing about dark energy is producing this outward push, this anti-gravity?
	2016-04-27: What Does Dark Energy Really Do? 01:59: So we need to figure out how far it traveled, the actual physical amount of space the photon had to traverse to get to us. 02:26: Redshift is the amount the universe expanded during a photon's journey, and distance is the amount of physical space it travelled through.
	2016-04-20: Why the Universe Needs Dark Energy 00:08: ... the largest scales-- of a volume of space vastly beyond our capacity to physically explore and at a time billions of years in the ...
	2016-04-06: We Are Star Stuff 02:25: ... single one of them, the actual physical stuff of your body, of the Earth, of everything you can see, was at one ...
	2016-03-09: Cosmic Microwave Background Challenge 02:28: So first question-- what physical distance did that light from the CMB travel through an expanding universe to reach us today?
	2016-02-11: LIGO's First Detection of Gravitational Waves! 04:24: They cause actual physical distances to change.
	2016-01-06: The True Nature of Matter and Mass 03:45: Again, we can describe this in terms of a straightforward physical effect. 04:16: ... seemingly very different physical effects-- the box of photons and the compressed spring-- both give the ... 03:45: Again, we can describe this in terms of a straightforward physical effect. 04:16: ... seemingly very different physical effects-- the box of photons and the compressed spring-- both give the same ...
	2015-12-09: How to Build a Black Hole 03:52: So two fermions can apply the same physical location just fine, as long as their momenta or any other quantum property is different.
	2015-10-28: Is The Alcubierre Warp Drive Possible? 03:19: There's just no guarantee that the resulting mass/energy distribution would be physically meaningful.
	2015-10-22: Have Gravitational Waves Been Discovered?!? 10:30: ... the idea is, you have this gigantic physical or magnetic funnel ahead of your craft, which scoops up this ... 00:51: Einstein is amazing, because every one of these predictions from his beautiful work has been physically tested and verified.
	2015-10-07: The Speed of Light is NOT About Light 04:17: This transformation thing, it's like a mathy magic wand that you wave at your description of spacetime or your physical laws.
	2015-08-27: Watch THIS! (New Host + Challenge Winners) 04:40: You know, physical intuition is incredibly important and you can go a really long way verbally talking through a physics problem.
	2015-08-19: Do Events Inside Black Holes Happen? 03:37: It's all the events that have ever or will ever take place there, according to observers who are physically there.
	2015-08-12: Challenge: Which Particle Wins This Race? 03:12: The point is to figure out the general answer through a combination of physical reasoning and algebra.
	2015-07-15: Can You Trust Your Eyes in Spacetime? 01:22: Our principle tool for exploring flat spacetime geometry will be something called a spacetime diagram for representing physical events. 02:21: Now recall from our earlier flat spacetime episode that points on this blackboard are not locations in a two-dimensional physical space. 02:28: Rather, they are events, each of which occurs somewhere along my axis in a one-dimensional physical space and at some moment according to my clock. 06:57: ... representing dynamical phenomena from the physical world as geometric objects and relations in a tenseless mathematical ... 01:22: Our principle tool for exploring flat spacetime geometry will be something called a spacetime diagram for representing physical events. 02:21: Now recall from our earlier flat spacetime episode that points on this blackboard are not locations in a two-dimensional physical space. 02:28: Rather, they are events, each of which occurs somewhere along my axis in a one-dimensional physical space and at some moment according to my clock. 07:10: I want to wrap up by going back tangent vectors for a second because I haven't told you yet what they represent physically.
	2015-07-08: Curvature Demonstrated + Comments 05:18: ... that point in the video, the Earth it was shown was supposed to be the physical, three dimensional Earth, and we were taking a vector and moving along a ...
	2015-06-03: Is Gravity An Illusion? 07:48: So why are you insisting that the downward jolt we experience every day on Earth has a physical origin?
	2015-05-27: Habitable Exoplanets Debunked! 10:07: Except physically, that's not true.
	2015-05-13: 9 NASA Technologies Shaping YOUR Future 04:36: Now, right now it's just in the prototype phase, being used for experimental physical therapy, but in 10 years, I'm going to be jacked.
	2015-03-18: Can A Starfox Barrel Roll Work In Space? 00:47: --might be the most physically viable part of the game.

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