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	2022-11-16: Are there Undiscovered Elements Beyond The Periodic Table? 10:56: It turns out there are no simple set of principles to determine nuclear stability. 16:52: eliyah zayin has a thoughtful criticism of the use of the Copernican principle to argue that we can’t especially early in the universe. 10:56: It turns out there are no simple set of principles to determine nuclear stability.
	2022-11-09: What If Humanity Is Among The First Spacefaring Civilizations? 01:14: ... we have this thing called the Copernican principle, which states that we shouldn’t expect to find ourselves in a ... 01:34: But in principle you can extend this principle to time. 01:46: ... course the Copernican principle has to compete with the Anthropic principle, which states that we can ... 02:43: ... hear more about the anthropic and copernican principles, and how we can use them to calculate other surprising things about our ...
	2022-10-26: Why Did Quantum Entanglement Win the Nobel Prize in Physics? 17:10: In principle you could look at planets in other galaxies.
	2022-10-19: The Equation That Explains (Nearly) Everything! 03:07: ... all possible due to an extremely powerful concept in physics called the Principle of Least Action, which we’ve talked about in detail. It says that Nature ... 04:05: ... then the Lagrangian will have that symmetry too. And by applying the principle of least action to a Lagrangian with a continuous symmetry will reveal ...
	2022-10-12: The REAL Possibility of Mapping Alien Planets! 19:23: ... the Planck constant or the speed of light change? In principle, maybe, but the most natural thing to   change is the ratio of ...
	2022-08-24: What Makes The Strong Force Strong? 03:29: This restriction is known as the Pauli Exclusion Principle. 03:58: ... be something different in order for them to comply with the Exclusion Principle. ...
	2022-06-22: Is Interstellar Travel Impossible? 02:57: But there are proposed advanced forms of propulsion that could in principle accelerate a proper spacecraft to a fair fraction of the speed of light. 13:42: But it turns out there’s nothing in principle stopping us from slowly limping from one planetary system to the next. 18:11: ... that emerge from a black hole as Hawking radiation, could we in principle learn about the inside of the black hole, given that they are entangled ... 18:31: ... - if hawking radiation really is entangled with the black hole then in principle we can learn about the black hole interior by measuring ... 02:57: But there are proposed advanced forms of propulsion that could in principle accelerate a proper spacecraft to a fair fraction of the speed of light. 18:11: ... that emerge from a black hole as Hawking radiation, could we in principle learn about the inside of the black hole, given that they are entangled with ... 13:42: But it turns out there’s nothing in principle stopping us from slowly limping from one planetary system to the next.
	2022-06-15: Can Wormholes Solve The Black Hole Information Paradox? 00:26: ... quantum information, and even to  the holographic principle. Now,   the latest attempt to solve the black hole  ... 06:01: ... mentioned that the information paradox  inspired the holographic principle. The most   advanced form of this is AdS/CFT ... 00:26: ... quantum information, and even to  the holographic principle. Now,   the latest attempt to solve the black hole  information paradox are ...
	2022-06-01: What If Physics IS NOT Describing Reality? 04:05: ... quantum indeterminacy, entanglement, and the   uncertainty principle turn out to be the expected  behaviors of this sort of information ... 08:49: ... In a previous episode we saw how the uncertainty  principle arises from the limited knowledge that   we can extract from a ... 04:05: ... quantum indeterminacy, entanglement, and the   uncertainty principle turn out to be the expected  behaviors of this sort of information ... 08:49: ... other staples of quantum theory  - like the Heisenberg uncertainty principle.   In a previous episode we saw how the uncertainty  principle arises ...
	2022-05-04: Space DOES NOT Expand Everywhere 11:22: ... of a black hole. Its solution takes us to the realm of the holographic principle, and so we can’t go there today. But long story short - even with a ...
	2022-04-20: Does the Universe Create Itself? 07:08: ... was called the delayed choice experiment because, in principle, the second beamsplitter could be put in place only after the photons ... 09:48: ... Take this yet further and you have a version of the Strong Anthropic Principle: The only reality that can exist is one that can have observers whose ...
	2022-03-23: Where Is The Center of The Universe? 00:37: Ever since then, astronomers have embraced the Copernican principle, which states that we are NOT in a special place in the universe. 00:51: And the Copernican principle inspired another important idea - not only are we not the center of the universe, but the universe doesn’t have a center. 01:04: This is called the Cosmological principle. 01:06: ... neither the Copernican principle nor the Cosmological principle are actual laws of physics - they’re ... 11:28: He assumed a homogeneous universe and assumed the cosmological principle. 12:47: ... should point out that this doesn’t necessarily break the Cosmological principle because it could still be that our bubble is small on the most ... 00:51: And the Copernican principle inspired another important idea - not only are we not the center of the universe, but the universe doesn’t have a center. 01:06: ... are actual laws of physics - they’re philosophical positions - guiding principles that so far have not led us ...
	2022-03-08: Is the Proxima System Our Best Hope For Another Earth? 11:43: ... thick atmosphere and strong planetary magnetic field could in principle protect any surface dwellers, who would then get to enjoy pretty ... 19:37: ... the relative phase angle can in principle  be measured - that is, we  can see the difference in the phase ...
	2022-02-16: Is The Wave Function The Building Block of Reality? 02:24: ... function collapse was first proposed by Werner Heisenberg, one of the principle founders of quantum theory. Heisenberg and his friend Neils Bohr were ...
	2022-01-27: How Does Gravity Escape A Black Hole? 09:03: We have to be able to “see” that mass, at least in principle.
	2022-01-12: How To Simulate The Universe With DFT 06:59: ... for the other particles, for example through the Pauli exclusion principle and through quantum ... 17:05: ... for looking for impact evidence on the Moon - yes, in principle these impacts leave weird-shaped craters that we might be able to ...
	2021-12-20: What Happens If A Black Hole Hits Earth? 14:26: ... made as simple as possible, but no simpler” Occam’s razor is a guiding principle, not a rule. If the current model can’t be made to fit observation then ... 16:33: ... be taken seriously, fuzzballs need to satisfy the equivalence principle - the founding idea of general relativity that says that freefall in a ... 17:30: ... is related to AdS/CFT correspondence and the holographic principle, which we covered previously. It, says that vibrations in a quantum field ... 16:33: ... be taken seriously, fuzzballs need to satisfy the equivalence principle - the founding idea of general relativity that says that freefall in a ...
	2021-12-10: 2021 End of Year AMA! 00:02: ... defined momentum and as we know from the heisenberg uncertainty principle if a particle has perfectly defined position perfectly defined ...
	2021-11-17: Are Black Holes Actually Fuzzballs? 02:45: But in the case of air, the hidden information still exists and is, in principle, still measurable.
	2021-11-10: What If Our Understanding of Gravity Is Wrong? 08:15: ... we saw that the principle of least action  allows equations of motion to be extracted in a ... 17:26: That was right - but I then went on to call this a “principle of least proper time” by analogy to the principle of least action. 17:39: ... consistent with the whole action thing because the proper name is the principle of stationary action - and the maximum is also a stationary point - of ... 17:55: Many of you point out that you’re already adherents of the principle of least action. 15:36: Our last episode was all about the principle  of least action, and how this one simple idea sort of leads to all of physics.
	2021-11-02: Is ACTION The Most Fundamental Property in Physics? 00:02: ... them, it follows the shortest one. He proposed what you might call a Principle of Least Distance to define the path of light. Of course we now know ... 01:15: It seemed as if we’d stumbled on a powerful guiding pattern in nature - minimizing principles. 01:59: ... systems. So maybe we were still in the market for a simple guiding principle after ... 02:11: ... was Joseph-Louis Lagrange who found that principle. Consider again the ball flying through the air. We can describe that ... 03:33: ... in such a way that Action is always minimized. And so was discovered the Principle of Least Action. A century later William Hamilton made the important ... 04:29: ... the principle of Least Action is true, then it should be possible to figure out the ... 05:24: ... Principle of Least Action is so powerful that it really seems like it must be ... 05:52: ... you get the right answer. But you don’t even need to go that far. If the Principle of Least Action is really a fundamental law, then there should be a ... 07:09: ... shows us that the Principle of Least Action holds up in GR - but it reveals a lot more. First, it ... 08:06: ... that light always travels the path that minimizes its travel time - the principle of least time. Well it turns out that this is just a special case of a ... 09:24: ... there seems to be a conflict here. The principle of least action says that a particle will always land where the action ... 11:12: ... no coincidence, because the path integral is the quantum analog of the Principle of Least ... 12:59: ... application of the quantum action principle to the evolution through quantum states underpins modern quantum theory. ... 13:46: ... a path through the configuration space of ideas, guided by mysterious principles, not least of which is the Action - pointing the surest way to the ... 14:57: ... a huge shoutout to our Quasar supporter Michael Schneider. Hamilton's principle tells us that action must always be minimized or maximized. Michael, ... 15:58: ... theory does try to bring a philosophical perspective shift, which in principle can be incredibly useful. All great discoveries came from perspective ... 14:57: ... a huge shoutout to our Quasar supporter Michael Schneider. Hamilton's principle tells us that action must always be minimized or maximized. Michael, thank you ... 01:15: It seemed as if we’d stumbled on a powerful guiding pattern in nature - minimizing principles. 13:46: ... a path through the configuration space of ideas, guided by mysterious principles, not least of which is the Action - pointing the surest way to the ...
	2021-10-20: Will Constructor Theory REWRITE Physics? 02:40: ... and quantum mechanics, along with more fundamental conservation laws, or principles, to rule out impossible output states given an input state of a ... 03:11: ... David Deutsch says, if a quantum computer can, in principle, simulate any process in physics, then all of physics can be expressed in ... 05:44: Again, this task is impossible, since it’s ruled out by the laws of quantum mechanics and the principle of conservation of energy. 08:52: You have two qubits, which could in principle be entangled with each other. 10:42: ... the inevitable implications of simple statements like the equivalence principle and the invariance of the speed of ... 03:11: ... David Deutsch says, if a quantum computer can, in principle, simulate any process in physics, then all of physics can be expressed in terms of ... 02:40: ... and quantum mechanics, along with more fundamental conservation laws, or principles, to rule out impossible output states given an input state of a ...
	2021-10-05: Why Magnetic Monopoles SHOULD Exist 04:18: But in principle it could exist, and so could magnetic monopoles. 14:55: ... it - for example all the structure of solids, via the Pauli exclusion principle. ... 16:22: ... the structural support against collapse produced by the Pauli exclusion principle - is ... 16:42: So the answer is that the Pauli exclusion principle is never violated. 16:22: ... the structural support against collapse produced by the Pauli exclusion principle - is ...
	2021-09-21: How Electron Spin Makes Matter Possible 00:26: ... doesn’t immediately collapse. It’s the source of the Pauli exclusion principle, and today I’m going to show you exactly why this simple property makes ... 02:18: ... non-overlap-ability of fermions is called the Pauli exclusion principle. I’m going to show you why this is the inevitable behavior of groups of ... 07:22: ... we need to get to the spin-statistics theorem, and the Pauli exclusion principle. Now all we need is to do is the ... 13:03: ... spinors having anti-symmetric wavefunctions, is the pauli exclusion principle. That is, particles with half integer spin have antisymmetric ... 14:00: ... have an anti-symmetric wavefunction and so must obey the Pauli exclusion principle - or you get ...
	2021-08-18: How Vacuum Decay Would Destroy The Universe 04:42: ... Heisenberg uncertainty principle tells  us that there’s a fundamental uncertainty   in - ...
	2021-08-10: How to Communicate Across the Quantum Multiverse 01:29: ... independently of each other due to something called the superposition principle. This principle also applies to the wavefunction in quantum ... 01:46: ... wavefunction corresponding to our “world”, and due to the superposition principle our world can happily do its thing unperturbed by other parts of the ... 04:30: ... through each other without being scrambled is due to the superposition principle. Let’s dig a little deeper. This principle says that you can determine ... 05:54: ... - and a linear wave equation is what you need for the superposition principle to be ... 06:09: ... in the physical world the superposition principle only holds to a point. Real pond surfaces or air density fields don’t ... 06:28: ... mechanics it’s always assumed that linearity and the superposition principle hold. Stack wavefunctions on top of each other and they behave as though ... 07:14: ... - they would exist across the entire wavefunction. And that, in principle, could give a way to explore what happens to the wavefunction after ... 08:55: ... tell us how to do this - he only proves that it should be possible in principle. ... 06:28: ... mechanics it’s always assumed that linearity and the superposition principle hold. Stack wavefunctions on top of each other and they behave as though the ...
	2021-08-03: How An Extreme New Star Could Change All Cosmology 06:21: ... forbidden by quantum mechanics - specifically, by the Pauli exclusion principle, which tells us that particles in the fermion family, like elelectrons, ... 15:19: ... just pass through the wall is something else - it’s the Pauli Exclusion principle, which says that electrons in atoms can’t be shoved into each other to ...
	2021-07-13: Where Are The Worlds In Many Worlds? 01:44: Here, we’re seeing the principle of superposition in action. 01:47: ... wave mechanics, this principle tells us that when two waves overlap, their amplitude - in this case the ... 01:58: But the superposition principle also tells us something much cooler. 02:43: The superposition principle only applies up to a point. 02:46: If the amplitude of the waves is is too high, the principle can break down. 02:58: At the risk of getting technical, the superposition principle holds for any linear system - and I’ll say more about that another time. 03:13: But the superposition principle seems to always hold for the waves that drive quantum mechanics. 02:58: At the risk of getting technical, the superposition principle holds for any linear system - and I’ll say more about that another time. 01:47: ... wave mechanics, this principle tells us that when two waves overlap, their amplitude - in this case the ...
	2021-07-07: Electrons DO NOT Spin 13:00: ... behavior of fermions   manifested as the Pauli Exclusion  Principle and is responsible for us having a periodic table, for electrons  ... 14:32: ... it represents the information contained in the system and extractable in principle, versus information that’s lost to the system by entanglement with ... 10:51: And by Heisenberg's uncertainty principle   increasing your knowledge of one, means  increasing the unknowability of the other.
	2021-06-16: Can Space Be Infinitely Divided? 03:47: ... going - we’re about to discover   the Heisenberg uncertainty principle. Bare  with me though with just a touch of ... 04:49: ... the Heisenberg microscope. We now know that the uncertainty principle is far more   fundamental than just the effect of disturbing ... 05:08: ... point I want to focus on today is that through the uncertainty principle we see that the Planck   constant represents the limit to ... 08:37: ... down as much as possible.   But the Heisenberg uncertainty principle says  that when we do that we increase the uncertainty   ... 09:58: ... on the Planck scale. At that scale,   Heisenberg’s principle tells us that the  curvature of space is fundamentally ... 03:47: ... going - we’re about to discover   the Heisenberg uncertainty principle. Bare  with me though with just a touch of ... 08:37: ... down as much as possible.   But the Heisenberg uncertainty principle says  that when we do that we increase the uncertainty   in momentum ... 09:58: ... on the Planck scale. At that scale,   Heisenberg’s principle tells us that the  curvature of space is fundamentally ...
	2021-05-25: What If (Tiny) Black Holes Are Everywhere? 11:17: ... yet, and then the one on how to mess with the limits of the uncertainty principle in detecting gravitational ... 13:36: ... onto the episode where we looked at how the Heisenberg uncertainty principle can be gamed to improve measurements - in particular in gravitational ... 15:08: ... our title from last week - we called it “Breaking the Uncertainty Principle”, but you rightly - if pedantically - pointed out that it should have been ...
	2021-05-19: Breaking The Heisenberg Uncertainty Principle 00:07: And in some cases succeeding, by squeezing the Heisenberg uncertainty principle to its breaking point. 00:47: ... absolute quantum limit - the limit defined by the Heisenberg Uncertainty Principle. ... 01:05: Today we’re going to see how the uncertainty principle can be hacked to make measurements more precisely than should ever be possible. 01:13: ... Heisenberg uncertainty principle tells us that there exists a fundamental unknowability to nature - an ... 01:41: ... these pairs of properties complementary variables, and the uncertainty principle tells us that the uncertainties in our knowledge of such a pair, when ... 01:58: Werner Heisenberg discovered the uncertainty principle when he was inventing his version of quantum mechanics back in the 1920s. 02:05: That version is called matrix mechanics, but we get the same uncertainty principle using the wave mechanics of Schrodinger. 02:13: ... it - so to get an idea of the fundamental source of the uncertainty principle, you can watch our episode on how it comes about from thinking about ... 02:56: Basically, he thought the uncertainty principle arose as a result of the measurement disturbing the system. 03:13: He thought the uncertainty principle was hinting at a far more fundamental law of the universe. 03:18: ... viewed it as an example of a principle of reality that he called “complementarity.” Bohr developed this ... 04:10: The Heisenberg uncertainty principle prevents us from being able to know everything about a quantum state all at once. 04:23: Remember, the uncertainty principle places a lower limit on the product of the uncertainties of pairs of complementary properties. 04:30: ... for example, if we only care about a particle’s position we can in principle measure it to extreme precision as long as we’re happy to have no ... 04:47: ... us to manipulate quantum states to push the limits of the uncertainty principle. ... 06:21: And this is where the uncertainty principle comes in. 06:53: Unless we can hack the uncertainty principle. 07:25: ... light from a laser beam obeys the Heisenberg uncertainty principle in a very specific way—it has equal amounts of uncertainty in its two ... 07:35: ... circle is proportional to Planck’s constant, satisfying the uncertainty principle. ... 10:03: ... have demonstrated this same principle in other systems like entangled atomic clocks, which may one day ... 10:17: ... bend a few fundamental laws - in this case, the Heisenberg uncertainty principle - we can push the limit beyond what we thought possible to force ever ... 02:56: Basically, he thought the uncertainty principle arose as a result of the measurement disturbing the system. 04:30: ... for example, if we only care about a particle’s position we can in principle measure it to extreme precision as long as we’re happy to have no knowledge of ... 04:23: Remember, the uncertainty principle places a lower limit on the product of the uncertainties of pairs of complementary properties. 04:10: The Heisenberg uncertainty principle prevents us from being able to know everything about a quantum state all at once. 01:13: ... Heisenberg uncertainty principle tells us that there exists a fundamental unknowability to nature - an absolute ... 01:41: ... these pairs of properties complementary variables, and the uncertainty principle tells us that the uncertainties in our knowledge of such a pair, when ...
	2021-04-21: The NEW Warp Drive Possibilities 17:32: ... now I see it’s an ancient viking metaphor for the Heisenberg uncertainty principle. ...
	2021-03-23: Zeno's Paradox & The Quantum Zeno Effect 05:23: ... in principle this would also work for radioactive decay, even chemical reactions The ...
	2021-03-16: The NEW Crisis in Cosmology 15:19: ... Smith Noted that the Huygen's Principle seems eerily similar to the double slit experiment if   ... 16:28: ... Feynman connection also - pointing out   the Huygen's principle feels like Feynman's  path integral formulation of quantum ... 15:19: ... so the story goes - and   he'd just figured out Huygen-Fresnel principle all on his own - a couple of hundred years late, but   independently ... 16:28: ... Feynman connection also - pointing out   the Huygen's principle feels like Feynman's  path integral formulation of quantum ... 15:19: ... Smith Noted that the Huygen's Principle seems eerily similar to the double slit experiment if   there were an ...
	2021-03-09: How Does Gravity Affect Light? 02:09: In general relativity, the best place to start is always the equivalence principle. 03:29: ... equivalence principle tells us that we must experience all the same physics if at rest in a ... 05:13: Let’s start with the good-old equivalence principle again, and a spaceship attacked by giant alien spiders. 05:48: And the equivalence principle tells us we must see the same bending of the light ray in our stationary rocketship set in our gravitational field. 07:35: A big part of that was his Huygens or Huygens-Fresnel Principle. 09:17: ... a very classical, 17th-century style plane wave so you can use Huygens' principle. ... 10:47: And even if this change in velocity isn’t “real”, it’s enough to let us use Huygen’s principle. 03:29: ... equivalence principle tells us that we must experience all the same physics if at rest in a ... 05:48: And the equivalence principle tells us we must see the same bending of the light ray in our stationary rocketship set in our gravitational field.
	2021-02-24: Does Time Cause Gravity? 00:34: ... the same as that induced by gravity - the so-called equivalence principle. ...
	2021-02-17: Gravitational Wave Background Discovered? 00:00: ... and the ceiling right that's a subtlety that i skipped the equivalence principle is technically only true in a uniform gravitational field so if the ...
	2021-02-10: How Does Gravity Warp the Flow of Time? 00:25: ... gravitational field does not exist.” We now know this as the equivalence principle - it states that there’s no experiment that you can do to distinguish a ... 05:45: To get to gravitational time dilation all we need to do is add in the equivalence principle as our second axiom. 08:54: The equivalence principle demands that there’s no experiment that can distinguish between acceleration and gravity. 00:25: ... gravitational field does not exist.” We now know this as the equivalence principle - it states that there’s no experiment that you can do to distinguish a ... 08:54: The equivalence principle demands that there’s no experiment that can distinguish between acceleration and gravity.
	2021-01-26: Is Dark Matter Made of Particles? 15:11: ... accelerate again to turn around, and according to Einstein’s equivalence principle, acceleration is fundamentally the same as gravitation as far as the laws ...
	2020-12-22: Navigating with Quantum Entanglement 04:52: In principle it’s easy to come up with ways to sense a magnetic field.
	2020-12-08: Why Do You Remember The Past But Not The Future? 05:01: ... you perfectly retrace its past.a In that idealized scenario, could in principle trace the jiggling of its internal quarks backwards to learn when the ... 07:33: If the rock never interacts with any external influence and just decays over time, then in principle we could calculate that decay. 05:01: ... you perfectly retrace its past.a In that idealized scenario, could in principle trace the jiggling of its internal quarks backwards to learn when the proton ...
	2020-11-18: The Arrow of Time and How to Reverse It 11:16: ... fuel for our choices.. Now if those random numbers are not even in principle learnable by some snooping entity, then it doesn’t matter whether they ...
	2020-11-11: Can Free Will be Saved in a Deterministic Universe? 02:46: One of the most important rules of quantum mechanics is the principle of conservation of quantum information. 04:23: ... new thread of quantum information, in violation with the conservation principle, or two, that this information just not be predictable even in principle ... 07:52: It's also impossible in principle. 08:05: ... is a direct consequence of the Heisenberg uncertainty principle, which tells us that measuring one property perfectly leaves a ... 08:16: ... brain or of the information threads that go into making it, either in principle or in practice, because unknown random processes are at work, and/or ... 12:06: ... it's not even in principle possible to perfectly predict a brain's choices, and that brain feels ...
	2020-10-20: Is The Future Predetermined By Quantum Mechanics? 04:15: At least as far as the Heisenberg Uncertainty Principle allows.
	2020-09-28: Solving Quantum Cryptography 09:40: The principle behind McEliece is that it’s really difficult to repair errors in large messages.
	2020-09-08: The Truth About Beauty in Physics 05:07: This is connected to the principle of parsimony, also known as Occam’s Razor.
	2020-08-24: Can Future Colliders Break the Standard Model? 15:40: In principle there should be a point right at the center where there is no flow - if you were a point-like particle you could just hang there.
	2020-08-10: Theory of Everything Controversies: Livestream 00:00: ... towards the big bang or in the center of black holes but also in principle every time we bring a particle into a superposition of two locations ...
	2020-07-28: What is a Theory of Everything: Livestream 00:00: ... of interests including string theory and loop quantum gravity in principle we could do this entire conversation just with stefan he's worked in ...
	2020-07-08: Does Antimatter Explain Why There's Something Rather Than Nothing? 04:05: ... could actually counteract CP violation, preserving CPT symmetry. In principle, at least. If CPT symmetry really IS violated however it may explain why ...
	2020-05-11: How Luminiferous Aether Led to Relativity 00:31: ... science like this “it seems probable that most of the grand underlying principles have been firmly established and that further advances are to be sought ...
	2020-04-28: Space Time Livestream: Ask Matt Anything 00:00: ... the exterior of the black hole is what started the whole holographic principle which leonard susskind then came in and gave a full sort of string ...
	2020-04-22: Will Wormholes Allow Fast Interstellar Travel? 12:51: ... may fluctuate wildly, its form shifting due to Heisenberg’s uncertainty principle. The result is what we call the spacetime foam, and it may imply that ...
	2020-04-07: How We Know The Earth Is Ancient 04:32: ... several in our solar system. Astronomers now swear by the Copernican principle - Earth is not in a privileged position in the universe, and so the laws ... 07:17: ... it takes for half of a large number of radioactive nuclei to decay. In principle, if you know how much of the stuff there was to start with you can figure ... 04:32: ... several in our solar system. Astronomers now swear by the Copernican principle - Earth is not in a privileged position in the universe, and so the laws ...
	2020-03-31: What’s On The Other Side Of A Black Hole? 12:02: ... only occur between two particles. What you're thinking about is the principle of monogamy of entanglement, which states that a given quantum state can ...
	2020-03-24: How Black Holes Spin Space Time 10:27: ... way the rotational energy can be extracted with, in principle, 100% efficiency. Oh, and you can also build a black hole bomb this way - ...
	2020-02-24: How Decoherence Splits The Quantum Multiverse 06:28: In principle we can bring those parts of the wavefunction back together to cause interference.
	2020-02-03: Are there Infinite Versions of You? 06:39: ... in principle there is an allowable level of ridiculously tiny deviation in the ...
	2020-01-20: Solving the Three Body Problem 00:20: ... of the bodies of the solar system, Newton’s equations could be used in principle be used to calculate their locations at any distant time, future or ... 12:21: ... which successive terms diminished to effectively nothing, so in principle the equation could be written out on paper. However the convergence of ...
	2020-01-06: How To Detect a Neutrino 04:46: ... energy conservation by taking advantage of the Heisenberg uncertainty principle, ♪ ♪ which tells us that there's a fundamental uncertainty ♪ ♪ between ...
	2019-12-17: Do Black Holes Create New Universes? 00:42: In recent episodes we explored one possible explanation for this - the anthropic principle and the idea of the multiverse. 01:02: But if you don’t like the anthropic principle - and many scientists don’t - then rest assured, there’s an alternative. 08:37: But, whoopsie, I just invoked the anthropic principle, which is exactly what were trying to avoid with this whole idea. 10:59: ... tries to avoid the anthropic principle by proposing a natural selection that favours black hole production, and ... 01:02: But if you don’t like the anthropic principle - and many scientists don’t - then rest assured, there’s an alternative.
	2019-12-09: The Doomsday Argument 00:25: ... some recent episodes we’ve explored the anthropic principle and seen how it can be used to explain the fact that both our planet and ... 00:47: We touched on both the potential power and potential misuse of this principle. 01:03: To use the anthropic principle properly we need to use it carefully. 01:07: ... talked about weaving in the Copernican principle which tells us that, all else being equal, we should expect to be in a ... 01:16: This is seemingly the opposite notion to the Anthropic principle. 02:33: ... is a good candidate for the anthropic principle - perhaps we’re just in one of the lucky universes with a low ... 04:15: ... refinement of the anthropic principle to talk about observers rather than environments is essentially using ... 05:07: And that’s the same guy who brought to popular attention and in fact named the anthropic principle to start with. 08:17: ... can go into - but it’s worth covering some that get at how the anthropic principle is interpreted, in particular through the self-sampling assumption and ... 02:33: ... is a good candidate for the anthropic principle - perhaps we’re just in one of the lucky universes with a low cosmological ... 01:03: To use the anthropic principle properly we need to use it carefully.
	2019-12-02: Is The Universe Finite? 12:50: OK, so in the last episode we explored the scientific and philosophical implications of the anthropic principle. 13:53: Scott Barnkow asks what are some testable predictions of the refined anthropic principle?
	2019-11-18: Can You Observe a Typical Universe? 00:07: The anthropic principle guarantees that you are NOT seeing the universe in its most typical state. 00:19: So, how do you correctly use the anthropic principle? 01:00: ... central nor privileged position in the universe is called the Copernican principle after the guy who started it ... 01:28: The Copernican principle became such a powerful tool that it took centuries for us to realize that it’s wrong - or at least flawed. 02:08: This is the anthropic principle, and it seems to contradict the sacred Copernican principle. 02:13: ... of the universe, and how these feed into two versions of the anthropic principle. ... 02:25: ... we’re going to bring these ideas together with the Copernican principle to see just how powerful - and how misleading - the anthropic principle ... 02:35: ... to the original definitions by Brandon Carter, the weak anthropic principle states that we must live in a place and time in the universe capable of ... 03:10: ... just call it the anthropic principle: we necessarily observe from an environment capable of producing ... 03:44: ... anthropic principle permits a new explanation for this fine-tuning besides blind luck or ... 04:13: This use of the anthropic principle is highly contentious. 04:31: Some of the bad rap of the anthropic principle comes from a distortion of the idea. 04:37: ... the 1986 book the Anthropic Cosmological Principle, John Barrow and Frank Tipler misinterpret the strong anthropic principle ... 04:54: But this commits the same flaw in reasoning that the anthropic principle may solve. 05:00: The principle is NOT causal - it just tells us to account for an observer selection bias when interpreting the nature of our environment. 05:17: ... other common misuse is to assume that the anthropic principle allows for any degree of extreme fine tuning of the properties of our ... 06:32: We certainly don’t observe the universe in a typical, observer-hostile state, and and so it’s tempting to use the anthropic principle here. 06:57: The anthropic principle appears to fail here, - but to understand why we need to go all the way back to the Copernican principle. 07:05: In fact we need to bring these two seemingly conflicting principles together. 07:10: And in doing so we’ll end up with a much more powerful version of the anthropic principle - one that will even make testable predictions. 07:19: By the Copernican principle, we are most likely to observe a very typical environment - this is just a statement of probability. 07:32: ... anthropic principle tells us we must account for our status as observers when we interpret ... 07:42: ... let’s formulate a refined anthropic principle: we should find ourselves in a typical region of the cosmos that is ... 08:15: This refined anthropic principle gets really interesting when applied to our low entropy big bang. 08:59: Our refined anthropic principle appears to fail here - but actually it doesn’t. 09:03: We’ve just witnessed the potential power of this principle. 09:08: ... random fluctuation in an otherwise high-entropy cosmos, the anthropic principle predicts that we should be in the smallest such fluctuation that could ... 09:55: For the anthropic principle to be useful and not misleading, we need to be careful. 10:41: The anthropic principle and the self-sampling assumption encourage Bayesian thinking. 11:15: Anything capable of thinking about the anthropic principle? 11:41: The anthropic principle in its proper form is without question an important thing to take into account whenever we observe the universe. 12:46: Used well the anthropic principle gives us a deep perspective on our place in the cosmos, and can also be a powerful, albeit slippery scientific tool. 15:44: ... right - that's possible - but the point is that UNLESS that principle is somehow connected to the universe's later developing life and ... 15:59: ... just as easy to imagine a physical principle that gives you only one universe with an unavoidable combination of ... 07:10: And in doing so we’ll end up with a much more powerful version of the anthropic principle - one that will even make testable predictions. 06:57: The anthropic principle appears to fail here, - but to understand why we need to go all the way back to the Copernican principle. 08:59: Our refined anthropic principle appears to fail here - but actually it doesn’t. 00:07: The anthropic principle guarantees that you are NOT seeing the universe in its most typical state. 04:37: ... the 1986 book the Anthropic Cosmological Principle, John Barrow and Frank Tipler misinterpret the strong anthropic principle to ... 03:44: ... anthropic principle permits a new explanation for this fine-tuning besides blind luck or design: if ... 09:08: ... random fluctuation in an otherwise high-entropy cosmos, the anthropic principle predicts that we should be in the smallest such fluctuation that could produce ... 02:35: ... to the original definitions by Brandon Carter, the weak anthropic principle states that we must live in a place and time in the universe capable of ... 07:32: ... anthropic principle tells us we must account for our status as observers when we interpret our ... 07:05: In fact we need to bring these two seemingly conflicting principles together.
	2019-11-11: Does Life Need a Multiverse to Exist? 02:34: This last possibility draws on something called the anthropic principle. 02:37: ... the last episode we talked about the anthropic principle as it related to where we find ourselves in this universe - necessarily ... 02:56: This is the so-called “weak” anthropic principle, as defined by astrophysicist Brandon Carter in 1973. 03:13: ... themselves, neither version of the anthropic principle explain why life-friendly planets or universes exist; they just say that ... 03:27: ... strong anthropic principle tells us that there’s an observer selection bias that may help us ... 10:48: Leaving aside the blind luck or intentional knob-fiddling for now, let’s get back to the anthropic principle. 12:34: ... albeit speculative ideas about multiverses, the strong anthropic principle seems to make sense of the incredible fine tuning of our own ... 13:09: ... life may be extremely rare, and how this relates to the weak anthropic principle. ... 15:24: ... - the fine tuning of our planet is less clear, but the weak anthropic principle makes it a totally plausible ... 03:13: ... themselves, neither version of the anthropic principle explain why life-friendly planets or universes exist; they just say that if such ... 03:27: ... strong anthropic principle tells us that there’s an observer selection bias that may help us understand ...
	2019-11-04: Why We Might Be Alone in the Universe 00:38: The anthropic principle tells us that we shouldn’t expect to find ourselves in some random corner of the multiverse - there’s an observer bias. 00:47: In upcoming episodes we’ll be exploring this principle and its two main versions - the strong and the weak anthropic principles. 00:57: ... strong anthropic principle tells us that an observed universe must be able to produce observers - ... 01:11: But today we’re going to focus on the weak anthropic principle, although it’s anything but weak. 01:41: And the weak anthropic principle is much more useful than that. 02:26: The weak anthropic principle places no limit on how rare those you-supporting environments are. 05:28: ... on Earth then it could be hugely uncommon - and the weak anthropic principle says it’s still not surprising for us to find ourselves on one of the ... 11:40: ... weak anthropic principle allows that these singular events were phenomenally unlikely - we simply ... 02:26: The weak anthropic principle places no limit on how rare those you-supporting environments are. 00:38: The anthropic principle tells us that we shouldn’t expect to find ourselves in some random corner of the multiverse - there’s an observer bias. 00:57: ... strong anthropic principle tells us that an observed universe must be able to produce observers - and ... 00:47: In upcoming episodes we’ll be exploring this principle and its two main versions - the strong and the weak anthropic principles.
	2019-10-21: Is Time Travel Impossible? 10:17: One way for a closed timelike curve to exist without causing a paradox is expressed in the Novikov Self-Consistency Principle.
	2019-10-15: Loop Quantum Gravity Explained 11:01: ... accepted forms, without taking away their most important foundational principles. ...
	2019-09-30: How Many Universes Are There? 07:06: ... is an example of using the Anthropic Principle - we must exist in a universe capable of producing us, so if there are ... 07:20: People have also invoked the anthropic principle plus eternal inflation to explain a conundrum in string theory. 08:14: Enter the anthropic principle once again: eternal inflation gives us enough universes to easily populate the entire string landscape. 08:36: Some people aren’t comfortable with the anthropic principle. 07:06: ... is an example of using the Anthropic Principle - we must exist in a universe capable of producing us, so if there are ...
	2019-08-19: What Happened Before the Big Bang? 10:04: ... connections between inflation and string theory and with the holographic principle, as described in one of Stephen Hawking's last ...
	2019-08-06: What Caused the Big Bang? 08:29: ... fluctuate to different values, thanks to the Heisenberg uncertainty principle. ...
	2019-07-18: Did Time Start at the Big Bang? 11:36: ... interpretation of internal inflation that draws on the holographic principle all things we'll discuss in the future as we travel beyond the beginning ...
	2019-07-15: The Quantum Internet 08:33: ... we reach Ted – who should still get a copy of the original qubit C. In principle this can be done without the quantum channel ever becoming ...
	2019-07-01: Thorium and the Future of Nuclear Energy 02:49: ... or via a secondary loop of water I just described very very crudely. The principles behind the light water thermal reactor These are the most common because ...
	2019-05-09: Why Quantum Computing Requires Quantum Cryptography 04:21: Each highlights a different fundamental weirdness of quantum mechanics – the Heisenberg uncertainty principle and quantum entanglement. 04:38: ... uncertainty principle tells us that we cannot simultaneously know the values of certain pairs ... 06:37: You just switched between different quantum representations of reality and then back again, and so invoked the uncertainty principle. 10:21: Man-in-the-middle attacks are in principle still possible because Werner could impersonate Albert and Niels from the very start. 04:38: ... uncertainty principle tells us that we cannot simultaneously know the values of certain pairs of ...
	2019-05-01: The Real Science of the EHT Black Hole 08:24: In principle this could be a very narrow ring.
	2019-04-10: The Holographic Universe Explained 00:44: The holographic principle emerged from many subtle clues – clues discovered over decades of theoretical exploration of the universe. 00:51: ... a the foundations needed to glimpse the true meaning of the holographic principle. ... 04:06: ... figured out a concrete string theoretic realization of the holographic principle with AdS/CFT ... 15:16: ... that's actually the opposite of the proposition behind the holographic principle, which suggests that our percieved universe is the volume, but it can be ... 00:44: The holographic principle emerged from many subtle clues – clues discovered over decades of theoretical exploration of the universe.
	2019-04-03: The Edge of an Infinite Universe 02:15: ... and this will set us up finally for laying open the holographic principle. ... 08:49: ... by the way, was a key discovery on the path to the holographic principle, as we’ve discussed before and which I’ll . review again - but not ... 09:16: For the holographic principle we need the infinite boundary of a negatively-curved universe – an anti-de Sitter, AdS universe. 15:06: Stay tuned for the final installment of the holographic principle in not-so-infinitely-distant future of spacetime.
	2019-03-06: The Impossibility of Perpetual Motion Machines 01:36: Other types of over-balance wheels followed through to the Renaissance and worked on the same principle. 05:30: ... principle a Carnot engine could extract energy from a temperature gradient and ... 05:52: The Carnot cycle is, in principle, a perpetual motion process. 06:30: Indeed there are ideal systems that, from pure classical principles should run forever. 06:55: Due to the intrinsic quantum randomness of all particles, as expressed by the Heisenberg uncertainty principle, everything moves. 06:30: Indeed there are ideal systems that, from pure classical principles should run forever.
	2019-02-07: Sound Waves from the Beginning of Time 14:12: ... Now, while I agree that this isn't a hard rule, it's a good guiding principle to be dubious of new theories that contradict extremely well tested old ... 14:49: ... claims require extraordinary evidence." Again, this is a guiding principle, and it helps scientists sort through the overwhelming flood of poorly ...
	2019-01-30: Perpetual Motion From Negative Mass? 05:25: That sounds crazy, and so we must invoke the age-old guiding principle of science, on par with Occam’s razor: the crackpot conjecture. 06:04: ... founding postulate of GR is the equivalence principle, which states that there’s no experiment that can distinguish between the ... 06:17: ... equivalence principle only works if all masses experience the same acceleration in a given ... 10:32: We assumed that passive gravitational mass and inertial mass are the same thing – and that’s required by the equivalence principle. 11:10: ... the geodesic equation, which itself arises directly from the equivalence principle, or from Lagrangian mechanics – a more modern version of Newton’s laws of ... 11:31: So do we have to throw away the equivalence principle to avoid the worst craziness? 12:28: ... negative inertial mass can’t exist and we want to save the equivalence principle and the rest of physics, we need to conclude that negative mass of any ...
	2019-01-09: Are Dark Matter And Dark Energy The Same? 05:18: It should be the same as gravitational mass for the equivalence principle to hold.
	2018-12-20: Why String Theory is Wrong 13:44: ... principle the standard model lives somewhere in the string landscape, but without ...
	2018-11-07: Why String Theory is Right 13:17: There's plenty of historical precedent for mathematical beauty leading to truth, but there's no fundamental principle that says it has to.
	2018-10-31: Are Virtual Particles A New Layer of Reality? 07:29: The Heisenberg uncertainty principle tells us that the perfectly defined momenta of virtual particles means completely undefined position. 09:20: ... nothing can be so exact-- thanks, again, to the Heisenberg uncertainty principle. ... 07:29: The Heisenberg uncertainty principle tells us that the perfectly defined momenta of virtual particles means completely undefined position.
	2018-10-25: Will We Ever Find Alien Life? 11:26: But the principle applies to a doomsday tech, nuclear weapons, genocidal nanobots, willful or negligent environmental destruction, you name it. 13:32: Now, this is a type of gauge symmetry that, in principle, unifies fermions and bosons. 11:26: But the principle applies to a doomsday tech, nuclear weapons, genocidal nanobots, willful or negligent environmental destruction, you name it. 13:32: Now, this is a type of gauge symmetry that, in principle, unifies fermions and bosons.
	2018-10-18: What are the Strings in String Theory? 12:05: Ultimately, it also leads to the ultimate duality that is the holographic principle.
	2018-09-20: Quantum Gravity and the Hardest Problem in Physics 05:50: The Heisenberg uncertainty principle tells us the minimum energy of our beam for a given precision. 06:28: Steady viewers will remember that the uncertainty principle talks about the trade-off between position and momentum. 06:37: The uncertainty principle also defines the precision trade-off between time and energy. 06:54: For those of you who already watched our episode on the Heisenberg uncertainty principle, here's another way to think about this. 08:01: Given that sensible underlying structure, it's relatively routine to apply quantum principles, or quantize, most of the forces of nature. 06:28: Steady viewers will remember that the uncertainty principle talks about the trade-off between position and momentum. 05:50: The Heisenberg uncertainty principle tells us the minimum energy of our beam for a given precision. 08:01: Given that sensible underlying structure, it's relatively routine to apply quantum principles, or quantize, most of the forces of nature.
	2018-09-12: How Much Information is in the Universe? 01:25: That's the holographic principle, and we've talked a lot about some ideas leading up to it. 01:30: ... worry, the full holographic principle episode is still coming, but our recent episode on black hole entropy ... 05:35: In fact, in a sense, the holographic principle is a compression algorithm. 01:30: ... worry, the full holographic principle episode is still coming, but our recent episode on black hole entropy and some ...
	2018-09-05: The Black Hole Entropy Enigma 01:30: ... in terms of information theory and ultimately led to the holographic principle, which I promise we're getting to and are almost ... 11:10: ... hinted once or twice that this simple idea led to the holographic principle, the idea that the entire 3D volume of the universe is just a projection ...
	2018-08-23: How Will the Universe End? 16:09: In practice, the Heisenberg uncertainty principle makes this impossible. 16:12: But really, in principle, there's no minimum precision with which we can know the electron's location, so there's no minimum size.
	2018-08-15: Quantum Theory's Most Incredible Prediction 12:23: That means that it and the quantum mechanical principles on which it is founded are good representations of reality.
	2018-07-25: Reversing Entropy with Maxwell's Demon 06:46: ... to detect approaching particles and open the door, mechanisms which, in principle, don't increase ... 08:23: ... principle states that "any logically irreversible manipulation of information, ... 06:46: ... to detect approaching particles and open the door, mechanisms which, in principle, don't increase ... 08:23: ... principle states that "any logically irreversible manipulation of information, such as ...
	2018-07-18: The Misunderstood Nature of Entropy 02:14: In principle, that work can then be converted back into heat and so the temperature differential can be reestablished.
	2018-07-11: Quantum Invariance & The Origin of The Standard Model 09:13: ... we need to apply quantum principles to our field, like considering its internal or self energy and allowing ...
	2018-06-20: The Black Hole Information Paradox 04:41: ... believe more and more, only 15 years behind Hawking, that the accepted principles lead to a truly paradoxical conclusion." So it turns out that if we ... 06:21: It's essentially invisible, but in principle the information is still there. 09:03: And, in principle, those distortions could potentially influence outgoing Hawking radiation, allowing them to carry away their information. 09:39: Leonard Susskind formalized this idea in the context of string theory in what we now know as the holographic principle. 11:01: This violates the principle of monogamy of entanglement. 04:41: ... believe more and more, only 15 years behind Hawking, that the accepted principles lead to a truly paradoxical conclusion." So it turns out that if we ...
	2018-06-13: What Survives Inside A Black Hole? 01:32: ... and also the gateway to black-hole thermodynamics and the holographic principle. ...
	2018-05-23: Why Quantum Information is Never Destroyed 05:36: ... principle, a given wave function in a given potential could mean the wave function ... 07:58: But all of this talk of quantum mechanics being deterministic seems a bit at odds with the idea of quantum randomness and the uncertainty principle. 08:18: And the precision of the knowability of that value is defined by the uncertainty principle. 08:35: And in principle, make enough measurements and you can extract all of the information from a wave function.
	2018-05-16: Noether's Theorem and The Symmetries of Reality 00:17: These laws are consequences of a much deeper, more fundamental principle. 06:02: ... falls like magic out of another deep lore of the universe-- the principle of least action, which states that the universe will always choose the ... 06:24: It's a generalization of Fermat's principle, which states that light will always take the path between two points that minimizes the travel time. 06:32: ... principle of least action extends Fermat's principal to any object moving on any ... 06:43: ... principle of least action can be used to derive the laws of motion from the ... 06:52: In a sense, the principle is axiomatic. 07:07: Noether's allows us to figure out the true conserved quantities for any system that's evolving according to the principle of least action.
	2018-04-25: Black Hole Swarms 10:52: And the two-slit experiment-- well, in principle, yes.
	2018-04-04: The Unruh Effect 09:58: According to Einstein's equivalence principle, remaining stationary in a gravitational field is equivalent to acceleration in free space.
	2018-02-21: The Death of the Sun 04:08: ... run up against the Pauli exclusion principle, the rule that says is that fermions, like electrons, can't occupy the ...
	2018-01-17: Horizon Radiation 07:21: ... could, in principle, make the same oscillation by simultaneously hitting the drum everywhere ...
	2018-01-10: What Do Stars Sound Like? 05:05: We've spoken in depth about Fourier analysis in a recent episode on understanding the uncertainty principle, so I won't go to too much detail here.
	2017-12-13: The Origin of 'Oumuamua, Our First Interstellar Visitor 10:36: Well we generalize frequency as momentum because the Heisenberg uncertainty principle applies to momentum in general.
	2017-12-06: Understanding the Uncertainty Principle with Quantum Fourier Series 00:16: ... going to open the door to really understanding Heisenberg's uncertainty principle, and ultimately, quantum fields and Hawking ... 00:28: [MUSIC PLAYING] One of the most difficult ideas to swallow in quantum mechanics is Werner Heisenberg's famous uncertainty principle. 00:49: See, the apparent weirdness of the uncertainty principle hints at an even weirder underlying reality that gives rise to it. 01:31: But as you'll see today, in that unraveling, we are led unavoidably to Heisenberg's uncertainty principle. 01:40: The uncertainty principle is most often expressed in terms of position and momentum. 02:06: The uncertainty principle exists alongside this observer effect. 02:16: To understand the origin of the uncertainty principle, we don't need to know any quantum mechanics, at least not to start with. 02:29: However, it turns out that something like the uncertainty principle arises in any wave mechanics. 05:41: That sounds an awful lot like a frequency-time uncertainty principle for sound waves. 05:47: ... fundamental knowability of a sound wave, as is Heisenberg's uncertainty principle, it's more a statement about the sampling of frequencies needed to ... 09:40: So that's exactly the uncertainty principle. 10:45: The uncertainty principle, therefore, tells us that they must be completely unconstrained in position. 11:59: ... "Quantum Mechanics," which includes a great episode on the uncertainty principle. ... 02:29: However, it turns out that something like the uncertainty principle arises in any wave mechanics. 02:06: The uncertainty principle exists alongside this observer effect. 00:49: See, the apparent weirdness of the uncertainty principle hints at an even weirder underlying reality that gives rise to it.
	2017-11-02: The Vacuum Catastrophe 00:44: We saw in our recent episode that we can thank the Heisenberg uncertainty principle for this bizarre behavior. 01:55: ... satisfy the Heisenberg uncertainty principle, the vacuum state of any fuel oscillation must be half of the tiny Planck ... 08:56: But of course, it may be that advances in theory will resolve this catastrophe without requiring us to invoke the anthropic principle.
	2017-10-25: The Missing Mass Mystery 12:09: The energy is borrowed from the energy of the vacuum for the minuscule time allowed by the uncertainty principle.
	2017-10-19: The Nature of Nothing 01:09: ... defined, and this is impossible according to the Heisenberg uncertainty principle. ... 03:34: But here we run up against that pesky Heisenberg's uncertainty principle once again. 05:33: But the ultimate price is that virtual particles can exist only for the instant allowed by the Heisenberg uncertainty principle.
	2017-10-11: Absolute Cold 05:04: The Heisenberg Uncertainty Principle tells us that there is an absolute limit in the knowability of particular combinations of properties. 06:21: For example, the quantum fields that fill our universe also fluctuate due to the Uncertainty Principle resulting in what we know as vacuum energy. 07:24: For example, Brian Greene's Exploring Quantum History delves much more deeply into the Heisenberg Uncertainty Principle. 05:04: The Heisenberg Uncertainty Principle tells us that there is an absolute limit in the knowability of particular combinations of properties.
	2017-10-04: When Quasars Collide STJC 11:41: ... the fine-tuning problem isn't actually a mystery, or that the anthropic principle solves the problem without even changing the fundamental ...
	2017-07-12: Solving the Impossible in Quantum Field Theory 15:06: ... applying the principle of least action in the determination of probability amplitudes, it turns ...
	2017-07-07: Feynman's Infinite Quantum Paths 00:36: The Heisenberg uncertainty principle tells us that the more precisely we try to define one property, the less definable is its counterpart. 04:35: That piece of physics was the principle of least action. 08:06: That power comes from the principle of least action. 10:04: The quantum action principle gives the probability amplitude of changes in the state of the field. 11:50: The universe may obey the principle of least action, but Mr. Levine is more of a maximum action guy. 00:36: The Heisenberg uncertainty principle tells us that the more precisely we try to define one property, the less definable is its counterpart.
	2017-06-28: The First Quantum Field Theory 10:26: ... example, the Pauli exclusion principle tells you that you can only have one fermion, or electron quark, et ...
	2017-06-21: Anti-Matter and Quantum Relativity 03:06: Pauli realized that to explain electron energy levels in atoms, those electrons must obey a rule that we call the Pauli exclusion principle. 03:53: ... the same quantum state and therefore violating the Pauli exclusion principle. ... 07:23: This is where the Pauli exclusion principle comes back.
	2017-05-03: Are We Living in an Ancestor Simulation? ft. Neil deGrasse Tyson 03:51: That is a much deeper rabbit hole, one we'll need the holographic principle to explore. 08:19: But both ancestor simulations and Boltzmann brains require us to invoke something like the Copernican principle. 08:43: That last addendum is an application of the anthropic principle. 08:51: ... reasoning with a dash of the anthropic principle tells us that we should be the most typical, the most common type of ... 15:06: ... principle, if you were to take such an expanded cloud of particles and exactly ... 15:57: ... principle, a perfect set of particle positions and velocities could be found such ... 08:51: ... reasoning with a dash of the anthropic principle tells us that we should be the most typical, the most common type of observer, ...
	2017-04-26: Are You a Boltzmann Brain? 05:59: This is an application of the anthropic principle. 06:25: The anthropic principle may explain why we exist in monstrously improbable or rare circumstances. 06:32: But the principle doesn't allow us to assume a circumstance for our existence that is any more improbable than is absolutely necessary. 06:55: But it can also be thought of as an extension of the Copernican principle. 06:32: But the principle doesn't allow us to assume a circumstance for our existence that is any more improbable than is absolutely necessary.
	2017-04-19: The Oh My God Particle 10:42: So in principle, no one can regulate landing on it. 10:57: ... United Nations developed the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer ...
	2017-01-11: The EM Drive: Fact or Fantasy? 10:13: ... principle, yes, as long as the timing between the antennae can be kept precise ...
	2017-01-04: How to See Black Holes + Kugelblitz Challenge Answer 09:48: But it's not quite a black hole, and so in principle, the sphere doesn't have to collapse.
	2016-12-21: Have They Seen Us? 15:32: In principle, you can do that with a warp drive.
	2016-12-08: What Happens at the Event Horizon? 15:51: More generally, it allows pilot wave theory to agree with Heisenberg's uncertainty principle. 15:57: In the Copenhagen interpretation, the uncertainty principle describes the intrinsic randomness of the quantum world.
	2016-11-16: Strange Stars 03:27: The Pauli exclusion principle states that this is forbidden for fermions, the family of particles that neutrons belong to. 05:49: It's as though the quarks trick their way around the Pauli exclusion principle by having some of them put on silly disguises. 13:09: ... paradox, Hawking radiation, some string theory, the holographic principle, other ... 03:27: The Pauli exclusion principle states that this is forbidden for fermions, the family of particles that neutrons belong to.
	2016-10-19: The First Humans on Mars 10:07: They could in principle be any mass.
	2016-09-21: Quantum Entanglement and the Great Bohr-Einstein Debate 08:09: But the principle is the same.
	2016-09-14: Self-Replicating Robots and Galactic Domination 09:31: Perhaps a variation of the Anthropic Principle needs to be invoked.
	2016-06-22: Planck's Constant and The Origin of Quantum Mechanics 01:35: ... and more formally, the Heisenberg uncertainty principle, describes the smallest distance for which an object's location can be ... 02:12: ... Heisenberg uncertainty principle and the de Broglie wavelength, but also the Schrodinger equation, the ... 01:35: ... and more formally, the Heisenberg uncertainty principle, describes the smallest distance for which an object's location can be meaningfully ...
	2016-06-01: Is Quantum Tunneling Faster than Light? 09:07: ... it's within the uncertainty range defined by the Heisenberg uncertainty principle, which is perhaps the deeper principle from which the de Broglie ...
	2016-03-16: Why is the Earth Round and the Milky Way Flat? 00:44: Two key principles, equilibrium and symmetry.
	2016-01-27: The Origin of Matter and Time 04:40: ... besides the invariance of the speed of light, the other fundamental principle of Einstein's special relativity at play here is the Galilean relativity ...
	2016-01-13: When Time Breaks Down 05:20: But Einstein's equivalence principle tells us that a frame suspended in a gravitational field is indistinguishable from an accelerating frame.
	2016-01-06: The True Nature of Matter and Mass 06:33: ... equivalence principle tells us that the feeling of being accelerated out in space is ... 07:04: In fact, the equivalence principle tells us that the gravitational mass of an object and the inertial mass are the same thing. 06:33: ... equivalence principle tells us that the feeling of being accelerated out in space is fundamentally ... 07:04: In fact, the equivalence principle tells us that the gravitational mass of an object and the inertial mass are the same thing.
	2015-12-09: How to Build a Black Hole 03:15: ... neutron star fills this 6D quantum phase space depends on two important principles of quantum theory, the Pauli exclusion principle and the Heisenberg ... 03:34: The Pauli exclusion principle basically just says that two things can't occupy the same place at the same time. 05:04: Fortunately, there's another quantum phenomenon that let's us get around the Pauli exclusion principle. 05:10: The Heisenberg uncertainty principle tells us that the properties of a quantum entity are fundamentally uncertain. 06:04: ... Heisenberg uncertainty principle tells us that particular pairs of quantities, position and momentum or ... 06:32: Therefore, the Heisenberg uncertainty principle tells us that they must have highly undefined momenta. 03:34: The Pauli exclusion principle basically just says that two things can't occupy the same place at the same time. 05:10: The Heisenberg uncertainty principle tells us that the properties of a quantum entity are fundamentally uncertain. 06:04: ... Heisenberg uncertainty principle tells us that particular pairs of quantities, position and momentum or time ... 06:32: Therefore, the Heisenberg uncertainty principle tells us that they must have highly undefined momenta. 03:15: ... neutron star fills this 6D quantum phase space depends on two important principles of quantum theory, the Pauli exclusion principle and the Heisenberg ...
	2015-11-05: Why Haven't We Found Alien Life? 02:01: ... we're touching on the anthropic principle, which states that an observer will always observe a universe that can ...
	2015-10-28: Is The Alcubierre Warp Drive Possible? 01:23: First, it's important to note that this idea does not contradict the principle of a cosmic speed limit. 03:59: Any FTL device can, in principle, be used to make a time machine.
	2015-10-07: The Speed of Light is NOT About Light 01:21: But in his book, there's another, less well known idea-- his Principle of Relativity.
	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.
	2015-06-17: How to Signal Aliens 06:55: ... give you a general flavor of the seeming tension between the equivalence principle and common sense that can only be resolved once we change our concept of ... 09:28: I think the easiest is to invoke the equivalence principle.
	2015-06-03: Is Gravity An Illusion? 07:21: Einstein called it the equivalence principle, and if you buy it, then maybe the falling frames really are inertial.
	2015-03-25: Cosmic Microwave Background Explained 06:13: The short YouTube video here shows a demo of this principle in action.
	2015-03-04: Should We Colonize Venus Instead of Mars? 01:59: It also means more available carbon dioxide from which, in principle, you might extract oxygen.
	2015-02-25: How Do You Measure the Size of the Universe? 00:55: That's the part that we, in principle, can see with light or gravitational waves.
	2015-02-18: Is It Irrational to Believe in Aliens? 03:18: It's that the alternative is so contrary to a closely held scientific principle, that it's quite difficult to swallow.

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