
20221214: How Can Matter Be BOTH Liquid AND Gas?
 15:11: ... I can go back to the 1920’s and debate interpretations of quantum mechanics with Einstein and Schrödinger!” – well, then you’d need to learn ...


20221109: What If Humanity Is Among The First Spacefaring Civilizations?
 18:28: It’s call transactional quantum mechanics.


20221026: Why Did Quantum Entanglement Win the Nobel Prize in Physics?
 00:21: ... ingenious experiments that proved that the strangest prediction of quantum mechanics is actually ...
 02:03: ... to quantum mechanics, we not only don’t know which is which until the box is open, but ...
 03:01: Well, because quantum mechanics in it's standard form says so.
 03:36: ... are a few different interpretations of quantum mechanics that allow this hidden information, and they’re collectively known as ...
 04:03: Quantum mechanics was just too successful, and Neils Bohr was aggressive in pushing his Copenhagen interpretation.
 06:12: Apparently Feynman thought it was pointless because standard quantum mechanics was clearly correct.
 07:09: ... quantum mechanics says that those polarizations are undefined until measurement, when ...
 07:33: ... was convincingly violated in their experiments, which means quantum mechanics was working exactly as expected, implying no hidden ...
 08:35: ... direction the whole time and sort of conspire to look like standard quantum mechanics, even if they had real hidden ...
 12:37: ... and Aspect's work was all about testing the fundamentals of quantum mechanics  about getting closer to what its weirdness is really telling us ...
 13:43: ... Feynman was right in thinking that Clauser would never disprove standard quantum mechanics  but he was wrong in thinking that Clauser shouldn’t ...


20220928: Why Is 1/137 One of the Greatest Unsolved Problems In Physics?
 00:48: But there’s something so weird and so compelling about this number that many of the founders of quantum mechanics obsessed over it.
 01:34: As with much of quantum mechanics, it started with us watching the light produced as electrons flicked between energy levels in atoms.
 02:04: ... spectral lines was a major driver of the development of quantum mechanics, and one of its first great successes, first with the Bohr model ...


20220824: What Makes The Strong Force Strong?
 00:00: Quantum mechanics gets weirder as you go to smaller sizes and higher energies.


20220727: How Many States Of Matter Are There?
 08:00: But once you bring quantum mechanics into the picture, many strange states of matter become possible.
 12:09: ... matter allows us to use the tools of our material sciences  for example quantum mechanics and condensed matter physics  to help us understand why we see the ...


20220720: What If We Live in a Superdeterministic Universe?
 01:06: There have been many efforts to find a realist interpretation of quantum mechanics.
 01:34: Erwin Schrodinger, coinventer of quantum mechanics with Werner Heisenberg, was a big proponent of realism.
 01:55: Albert Einstein also came up with a scenario in which he tried to refute the nonrealist implications of pure quantum mechanics.
 02:20: ... “standard” quantum mechanics, the fundamental building block of reality is the wavefunction, which ...
 03:36: Standard quantum mechanics says that this is possible, but it leads to the seemingly absurd result of the EPR paradox.
 04:02: According to standard quantum mechanics, that spin is undefined until measurement.
 05:34: ... in a way that was somehow hidden from the wavefunction of standard quantum mechanics. ...
 06:36: ... the beginning and contained within the electron  but false if standard quantum mechanics is right and spin is undefined until ...
 06:59: That test thoroughly supported standard quantum mechanics.
 07:52: There are ways to save realism in quantum mechanics by crossing Einstein and abandoning locality.
 08:04: On the other hand, Many Worlds interpretation of quantum mechanics saves local realism at the cost of requiring multiple realities.
 08:47: But quantum mechanics says that when Alice measures her electron, Bob’s electron is instantly affected.
 14:09: Quantum mechanics has been telling us that we are not that for 100 years.


20220622: Is Interstellar Travel Impossible?
 15:08: We talked about how quantum mechanics can be derived as a model of our information about the world, rather than the world itself.
 15:31: Clay Farris Naff asks whether Zeilinger description of informational quantum mechanics is consistent with Hawking's lateinlife antirealist stance?
 16:09: But this is the philosophy behind Zeilinger’s interpretation of quantum mechanics.
 16:24: ... the waveparticle duality was explained in the context of informational quantum mechanics in that you couldn’t simultaneously extract answers to both ...


20220615: Can Wormholes Solve The Black Hole Information Paradox?
 01:40: ... of quantum information, which is a nonnegotiable constraint of quantum mechanics. ...
 06:54: ... the Page curve using only general relativity and accepted quantum mechanics  no string theories attached. To be fair, these US ...


20220601: What If Physics IS NOT Describing Reality?
 01:41: ... started talking about informational interpretations of quantum mechanics. Then we discussed one of the more radical ...
 02:20: ... right, but we can explore the power of informational quantum mechanics without committing to quite such a radical ...
 02:44: ... see if we can rebuild the world from those parts. In quantum mechanics, we have things like particles and fields which can only take ...
 03:22: ... Anton Zeilinger has proposed an informational approach to quantum mechanics in which the world is broken up not into physical parts, but into ...
 04:05: ... answer  a surprising number of the weird results of quantum mechanics suddenly make sense. Things like quantum indeterminacy, ...
 09:26: ... one of the original and most mysterious features of quantum mechanics  waveparticle ...
 10:33: ... both questions. So, they found that the waveparticle duality of quantum mechanics arises from the limited information, the inability to answer two ...
 11:24: ... believe to be the building blocks of reality. In quantum mechanics, we tend to think of the quantum wavefunction as pretty ...


20220504: Space DOES NOT Expand Everywhere
 10:33: ... that at the smallest scales, general relativity comes into conflict with quantum mechanics. There is a smallest measurable length called the Planck length. When ...


20220427: How the Higgs Mechanism Give Things Mass
 02:31: ... quantum mechanics, such a “redundant degree of freedom” leads to a gauge field. We’ve ...


20220420: Does the Universe Create Itself?
 00:59: ... then came the 20th century, and quantum mechanics. In quantum mechanics, not only does the act of measurement profoundly ...
 01:59: ... alive and dead until the box is open  a superposition of states. Or so quantum mechanics seems to suggest. This seems even more absurd when you add the socalled ...
 04:03: ... put the whole mess behind them and get on with the job of actually using quantum mechanics to invent the modern ...
 06:13: ... this case, quantum mechanics states that the photon is in a state of having been both transmitted and ...
 12:27: ... realism” we have things like quantum bayesianism and relational quantum mechanics, in which the universe emerges from the information that some set of real ...


20220316: What If Charge is NOT Fundamental?
 01:39: As with much of modern physics, this story begins with Werner Heisenberg, whose epiphanies birthed quantum mechanics.


20220308: Is the Proxima System Our Best Hope For Another Earth?
 17:13: But in general it means different branches of the wavefunction are able to influence each other, which is not the case in standard quantum mechanics.
 17:20: Check out our episode on the manyworlds or EverettWheeler telephone for juicy details on nonlinear quantum mechanics.
 17:45: ... that produce hopeless contradictions between general relativity and quantum mechanics. ...
 17:58: ... quantum mechanics and quantum field theory assume a welldefined underlying framework, ...


20220216: Is The Wave Function The Building Block of Reality?
 00:03: ... the world of quantum mechanics, it’s no big deal for particles to be in multiple different states at the ...
 00:49: ... quantum mechanics, particles don’t have definite properties. Rather they are described by ...
 02:24: ... was real. It’s a central part of their Copenhagen interpretation of quantum mechanics. But neither physicist claimed to know where or how wave function ...
 04:54: To understand how objective collapse theories work, we need just a little more quantum mechanics.
 09:25: ... Quantum mechanics rules when things are small, but add enough mass, and the gravity of the ...
 10:19: ... to the Schrödinger equation, they are not mere interpretations of quantum mechanics — they are distinct theories with unique predictions. This means that, ...


20220210: The Nature of Space and Time AMA
 00:03: ... the planck time and we know this because general relativity and quantum mechanics come into impossible conflict below these planck units of space and ...


20220127: How Does Gravity Escape A Black Hole?
 06:08: Now in quantum mechanics  or more specifically quantum field theory  forces are mediated by particles, not by the geometry of spacetime.


20220112: How To Simulate The Universe With DFT
 00:38: Quantum mechanics allows us to predict the behavior of the subatomic world with truly incredible precision.
 02:30: ... time independent Schrodinger equation isn’t the be all and end all of quantum mechanics  it’s an approximation that works for slower moving particles that ...
 02:39: But it’s where we start learning quantum mechanics, and it works for a lot of simple cases.
 05:39: ... in quantum mechanics often means finding a solution to a problem that’s much simpler than ...
 06:48: In quantum mechanics, we’re dealing with the wavefunction, and the wavefunction fills all of configuration space.
 06:59: ... only that, but quantum mechanics contains nonlocal correlations which arise because the position of one ...
 08:02: But if we want to keep the quantum behaviour of quantum mechanics we can’t throw away most of configuration space like we do in Newtonian mechanics.


20211210: 2021 End of Year AMA!
 00:02: ... the so so so we have this strange uh description of of the forces in quantum mechanics in particular in quantum field theory where two particles which are ...


20211117: Are Black Holes Actually Fuzzballs?
 01:00: At the central singularity, the known laws of physics break down  general relativity comes into irreconcilable conflict with quantum mechanics.
 04:17: Ultimately, the black hole paradoxes stem from the disagreement between quantum mechanics and general relativity.


20211110: What If Our Understanding of Gravity Is Wrong?
 15:45: ... if the configuration space Lagrangian seems to bridge quantum mechanics and relativity, what's missing to make this a theory of ...


20211102: Is ACTION The Most Fundamental Property in Physics?
 05:24: ... and into our modern theories  in particular general relativity and quantum mechanics. And perhaps in these we’ll find clues as to what the action is really ...
 08:31: OK, it seems like we’re getting somewhere. Let’s see if quantum mechanics will get us any deeper, or perhaps just make everything more confusing.
 08:39: ... with the famous double slit experiment, as we so often do when talking quantum mechanics. In it, a stream of quantum particles are launched at a barrier with two ...
 11:12: ... is Feynman’s path integral formulation of quantum mechanics, and it exactly reproduces the predictions of previous versions of ...
 12:16: ... spacetime, where the shortest path minimizes proper time. In quantum mechanics configuration space could mean phase space  the space of possible ...


20211020: Will Constructor Theory REWRITE Physics?
 01:43: ... mechanics and electromagnetism and so on from two master theories: quantum mechanics and Einstein’s general ...
 02:40: ... uses theories like general relativity and quantum mechanics, along with more fundamental conservation laws, or principles, to rule ...
 04:42: For example, understanding the union of quantum mechanics and general relativity.
 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.
 09:55: It doesn't need the dynamical laws of such a theory, or even of quantum mechanics or general relativity as they currently stand.
 10:51: ... Heisenberg came up with the first version of quantum mechanics by stripping away all but the bare facts about the nature of ...


20211013: New Results in Quantum Tunneling vs. The Speed of Light
 00:26: Quantum tunneling is one of the weirder phenomena in the generally very weird world of quantum mechanics.
 00:55: Now we covered quantum tunneling a long long time ago  in fact it was the first video we did on quantum mechanics.
 01:51: ... similar thing happens in the world of quantum mechanics, where particles are pushed and pulled by the fundamental forces, forming ...
 04:31: ... to determine the socalled tunneling time because, in the fuzzy world of quantum mechanics, it’s hard to even define what we mean by tunnelling time or time for ...
 17:04: And that process actually evades Hogwart's security wards because the wizards are rubbish at quantum mechanics.


20211005: Why Magnetic Monopoles SHOULD Exist
 04:24: But what about quantum mechanics?
 04:37: ... arose automatically from requiring that the equations of quantum mechanics had a particular symmetry  the measurements they predict are unaltered ...
 05:27: Quantum mechanics, as the saying goes, forbids it.
 06:52: In quantum mechanics, this works by shifting the phase of the particle’s wavefunction.
 08:45: Charge turns out to be quantized, so quantum mechanics doesn’t actually forbid monopoles.


20210921: How Electron Spin Makes Matter Possible
 00:26: ... around. That particular weirdness is not just another cute case of quantum mechanics being a bit silly. The fact that some particles have this property is ...
 18:44: ... kidding. I love astrophysics like my aweinspiring first born child. But quantum mechanics is my weird and brilliant and deeply compelling second born and I love ...


20210907: First Detection of Light from Behind a Black Hole
 12:26: Blinkist has an array of categories – from the science of Quantum Mechanics to philosophy to futurism.


20210810: How to Communicate Across the Quantum Multiverse
 00:00: ... from a different quantum timeline. I figured out the secret truth behind quantum mechanics and I’m sending it to Matt in your timeline so he can tell you. Stand ...
 01:29: ... principle. This principle also applies to the wavefunction in quantum mechanics. ...
 01:46: ... the Many Worlds interpretation of quantum mechanics, the universal wavefunction is the reality, encompassing all possible ...
 02:29: ... are other ways to interpret the math of quantum mechanics that don’t require a multiverse. For example there’s the Copenhagen ...
 02:56: ... now approaching 100 years since the discovery of quantum mechanics, and we still don’t know which of these  if any  are right. So what’s ...
 06:28: ... equation as we usually write it is a perfectly linear equation, and in quantum mechanics it’s always assumed that linearity and the superposition principle hold. ...
 12:00: ... idea really just serves as a proof of concept that in a nonlinear quantum mechanics, actions can influence the entire wavefunction  spanning different ...
 12:47: ... to summarize: either quantum mechanics is perfectly linear and you should forget I said anything, OR it’s ...


20210803: How An Extreme New Star Could Change All Cosmology
 06:21: ...  they’d have to occupy the same energy states. But that’s forbidden by quantum mechanics  specifically, by the Pauli exclusion principle, which tells us that ...
 08:05: ... known white dwarf it must also be the most massive. Doing a little quantum mechanics, it was found that it must weigh in at 1.32 times the Sun’s mass. And ...
 14:14: ... enthusiasm, we’d probably have sunk to spacethemed reaction videos and quantum mechanics based pranks. As always, thanks for everything. And today’s extra ...


20210721: How Magnetism Shapes The Universe
 13:47: ... exactly are the alternate worlds in the many worlds interpretation of quantum mechanics? ...
 18:20: ... Barefoot also point out that this divide isn’t needed for quantum mechanics to work  its perhaps only helpful in making us less freaked out by the ...
 18:42: Really, that entire series can be framed as an alternative interpretation of quantum mechanics.


20210713: Where Are The Worlds In Many Worlds?
 00:00: ... many worlds interpretation of quantum mechanics proposes that every time a quantum event gets decided, the universe ...
 00:44: We’ve talked before about this interpretation of quantum mechanics, and whether it’s plausibly true.
 03:13: But the superposition principle seems to always hold for the waves that drive quantum mechanics.
 03:35: And by jump through a pond I mean learn some quantum mechanics.
 03:39: Quantum mechanics is a theory about waves.
 04:32: The actual mechanics of quantum mechanics is all about determining the shape and evolution of the wavefunction.
 05:22: ... most mainstream interpretation of quantum mechanics  the Copenhagen Interpretation  tells us that the wavefunction ...


20210707: Electrons DO NOT Spin
 00:00: ... Quantum mechanics has a lot of weird stuff  but there’s one thing that everyone ...
 07:30: ... than that. To understand why we need to see how spin is described in quantum mechanics. It was again Pauli who had the first big success here. By the mid ...
 10:33: ... us the law of the conservation of momentum. For related reasons in quantum mechanics position and momentum are conjugate ...


20210623: How Quantum Entanglement Creates Entropy
 06:38: ... von Neumann entropy is about, let’s think about information in quantum mechanics. Quantum systems are described by what we call the wavefunction  ...


20210616: Can Space Be Infinitely Divided?
 01:16: ... the subatomic world. We now see it everywhere in quantum mechanics  it’s a fundamental constant of nature that defines the scale of ...


20210525: What If (Tiny) Black Holes Are Everywhere?
 00:50: ... in 1974, a young genius named Stephen Hawking showed that if you bring quantum mechanics into the equation, quite literally, then the black hole is neither black ...
 01:07: In a way quantum mechanics saves us from the eternal black hole … except perhaps that it doesn’t.
 01:16: ... the evaporation of the black hole all the way to the very last instant  quantum mechanics may well play a second trick and save that final speck of the black hole ...
 04:02: Researchers have come up with different hacks for combining general relativity and quantum mechanics and they reached the same conclusion.
 06:48: ... is the sizescale where general relativity and quantum mechanics come into hopeless conflict, and is sometimes thought of as the smallest ...
 09:36: That breaks one of the most sacred rules of quantum mechanics  the conservation of quantum information.


20210519: Breaking The Heisenberg Uncertainty Principle
 00:00: Quantum mechanics forbids us from measuringthe universe beyond a certain level of precision.
 01:41: ... quantum mechanics, we call these pairs of properties complementary variables, and the ...
 01:58: Werner Heisenberg discovered the uncertainty principle when he was inventing his version of quantum mechanics back in the 1920s.
 03:02: Heisenberg took his new idea to Niels Bohr  his mentor and one of the cofounders of quantum mechanics.
 03:18: ... when trying to reconcile the perplexing apparent contradictions in quantum mechanics. ...
 09:56: The use of squeezed light is just one example of how quantum mechanics can be used to increase measurement precision.


20210511: How To Know If It's Aliens
 14:48: ... is not our final theory of nature because it doesn’t perfectly gel with quantum mechanics. So maybe a theory of quantum gravity will reveal that warp drives are ...


20210421: The NEW Warp Drive Possibilities
 16:40: Actually, in quantum mechanics, velocity isn’t just change in position with time.
 17:14: So we can conclude that Odin knew quantum mechanics.
 17:47: So maybe Odin learned his quantum mechanics watching space time like the rest of us.


20210323: Zeno's Paradox & The Quantum Zeno Effect
 00:04: This has now been proven true by quantum mechanics.
 01:07: That’s what a mathematician might tell you  but quantum mechanics also has a thing or two to say about extremely tiny distances and time intervals.
 02:52: In the language of the Copenhagen interpretation of quantum mechanics, we say that the “wavefunction collapses” on observation.
 08:43: ... objection gets to the very foundations of quantum mechanics: what exactly do we mean by a “measurement” and what do we mean by ...
 12:17: ... will give us clues to unravel the deepest mysteries at the heart of quantum mechanics. ...
 13:04: ... the course you’ll explore everything from time in quantum mechanics to black hole entropy and learn what cuttingedge science has to say ...


20210316: The NEW Crisis in Cosmology
 16:28: ... principle feels like Feynman's path integral formulation of quantum mechanics. For those who don't know, the path integral calculates the ...


20210224: Does Time Cause Gravity?
 07:25: But actually general relativity doesn’t need quantum mechanics to explain gravity.


20210119: Can We Break the Universe?
 14:15: ... possible question: Could it be that asking which interpretation of quantum mechanics is "true" is like asking if light is made up of particles or if light is ...


20210112: What Happens During a Quantum Jump?
 00:00: Since the very beginning of quantum mechanics, a debate has raged about how to interpret its bizarre predictions.
 00:24: The notion of a quantum jump or quantum leap is one of the founding concepts of quantum mechanics.
 00:52: But one of the principal founders of quantum mechanics thought otherwise.
 01:56: ... and Erwin Schrodinger to develop the first complete formulations of quantum mechanics in ...
 02:34: To address questions like this, Bohr and Heisenberg teamed up to develop the “Copenhagen interpretation” of quantum mechanics.
 11:44: For the longest time, physicists have shied away from asking which interpretation of quantum mechanics is correct.


20201222: Navigating with Quantum Entanglement
 00:00: ... often think of quantum mechanics as only affecting only the smallest scales of reality, with classical ...
 00:29: Because it turns out we might need all the weirdness of quantum mechanics to explain birds.
 01:52: How do they do it and what does quantum mechanics have to do with all of this?
 05:33: And this is where quantum mechanics comes in.
 10:54: So Erwin Schrodinger’s ideas about quantum mechanics influencing living organisms may be right.


20201215: The Supernova At The End of Time
 03:37: The new science of quantum mechanics had shattered our classical understanding of the world in many ways.
 15:21: This one depends entirely on your choice of interpretation of quantum mechanics.


20201208: Why Do You Remember The Past But Not The Future?
 13:18: Ryan Christopherson asks whether the random nature of quantum mechanics isn’t a larger hurdle to the reversibility of time than entropy.
 13:33: ... answer is that yes, IF quantum mechanics is fundamentally random, and IF the wavefunction collapse is a random ...


20201118: The Arrow of Time and How to Reverse It
 00:24: ... describe a universe in rewind. That’s true from the subatomic realm of quantum mechanics to the cosmic realm of Einstein’s general relativity. But if time ...


20201111: Can Free Will be Saved in a Deterministic Universe?
 02:15: But understanding the implications of quantum mechanics is key to unraveling determinism and its connection to predictability.
 02:22: Quantum mechanics seems to tell us that one of the following is true.
 02:46: One of the most important rules of quantum mechanics is the principle of conservation of quantum information.
 05:42: That said, the most mainstream interpretation of quantum mechanics has the same problem.
 10:17: All possible futures exist and develop according to the laws of quantum mechanics.


20201104: Electroweak Theory and the Origin of the Fundamental Forces
 01:36: While the brand new field of quantum mechanics could describe the behaviour of electrons, nuclear processes remained mysterious.
 04:50: ... try an example: In quantum mechanics, the wavefunction determines the probabilities of certain outcomes being ...


20201027: How The Penrose Singularity Theorem Predicts The End of Space Time
 11:10: ... points. The resolution must be the union of general relativity and quantum mechanics  a theory of quantum gravity, from which both ...
 12:51: ... quantum mechanics had to say about the whole mess. Quantum mechanics had a few things to say, but you guys had more. Let’s get to the ...
 13:38: ... type of communication between worlds, but only works if quantum mechanics works in a particular nonlinear way We should probably do an ...


20201020: Is The Future Predetermined By Quantum Mechanics?
 02:38: We need to see what quantum mechanics says about determinism and how it plays with relativity and the block universe.
 02:46: According to quantum mechanics, physical systems, parts of the universe evolve as wave functions.
 04:23: ... function evolves in a precise way, perfectly defined by the equations of quantum mechanics but at the moment of measurement, a single reality is randomly selected ...
 04:45: Another popular interpretation of quantum mechanics is the ManyWorlds Interpretation, which simply states that the wave function never collapses.
 11:06: Copenhagen and ManyWorlds aren't the only interpretations of quantum mechanics in town.


20201013: Do the Past and Future Exist?
 01:44: Now quantum mechanics might argue otherwise, depending on which quantum mechanics you prefer, but we’ll come back to in an upcoming episode.
 12:00: To rescue materialism without demanding a perfectly defined personal future we need quantum mechanics.
 12:07: ... Quantum mechanics tells us that all this stuff outside our past lightcone  and even ...
 12:17: Depending on how you interpret quantum mechanics, that could be evidence in favor of this solipsistic denial of external reality.
 12:35: ... these ideas before  the Copenhagen and Many Worlds interpretations of quantum mechanics  but soon we’ll dive back in, to see what these idea imply about time, ...


20200928: Solving Quantum Cryptography
 06:59: ... parallel realities if you’re into the Many Worlds interpretation of quantum mechanics. ...


20200908: The Truth About Beauty in Physics
 07:19: ... Dirac, one of the principal founders of quantum mechanics, said “It is more important to have beauty in one's equation than to have ...
 11:30: His idea of introducing a new symmetry to space was translated to adding a new symmetry to the wavefunction in quantum mechanics.


20200901: How Do We Know What Stars Are Made Of?
 06:04: The brand new field of quantum mechanics was emerging in Europe, and a young astrophysicist named Cecilia Payne had just arrived at Harvard.


20200810: Theory of Everything Controversies: Livestream
 00:00: ... for the past century after the great revolutions of relativity and quantum mechanics so together with professor brian keating astrophysicist and friend ...


20200728: What is a Theory of Everything: Livestream
 00:00: ... also so he's worked in fields from cosmology to the foundations of quantum mechanics and now actually working deep in the field of deep learning and he's ...


20200708: Does Antimatter Explain Why There's Something Rather Than Nothing?
 04:05: ... universe of matter, and would undo a lot of what we think we know about quantum mechanics. So, good news bad news I ...


20200428: Space Time Livestream: Ask Matt Anything
 00:00: ... should be conserved it is quantum information and the reason is that quantum mechanics really really depends on the on the on this one concept on the ...


20200316: How Do Quantum States Manifest In The Classical World?
 00:44: ... Quantum mechanics tells us that the atom’s wavefunction can be in a superposition of ...
 00:57: ... seems absurd  but quantum mechanics appears to allow this. In fact the idea of superposition is fundamental ...
 04:28: ... came up with to demonstrate an apparent absurdity predicted by pure quantum mechanics. This is the socalled EinsteinPodolskyRosen, or EPR paradox. A high ...
 15:28: ... about a thought experiment to test the many worlds interpretation of quantum mechanics  quantum immortality, aka quantum suicide, in which a physicist will ...


20200303: Does Quantum Immortality Save Schrödinger's Cat?
 00:22: In the last couple of episodes we’ve been delving into a key mystery of quantum mechanics  why don’t we have quantum magical powers?
 01:18: ... in one of them, we need to embrace one of the interpretations of quantum mechanics. ...
 05:21: ... is right because the chance survival under any other interpretation of quantum mechanics is basically ...
 11:51: ... to address both our episodes on the role of conscious observation in quantum mechanics and on quantum decoherence as a better path to understanding the ...
 15:44: ... channel is pleased that we share his annoyance at horrible missuse of quantum mechanics to promote pseudoscientific ...
 15:55: As Nick says, "Quantum mechanics is not magic!".
 16:41: ... that a more interesting question than does consciousness influcence quantum mechanics is the other way around: "Does quantum mechanics influence ...
 16:54: Despite my fascination with the subject, I've dosed off in MANY quantum mechanics lectures.


20200224: How Decoherence Splits The Quantum Multiverse
 02:44: This fact is also reflected in Richard Feynman’s path integral formulation of quantum mechanics.
 06:53: And this is one of the weird, multiple history aspects of quantum mechanics that we can directly observe.
 14:19: ... argue that it does  in the context of the Many Worlds interpretation of quantum mechanics, in which there is no wavefunction collapses at ...


20200218: Does Consciousness Influence Quantum Mechanics?
 00:00: If I focus really hard do my power of quantum mechanics allow me to manifest reality?
 00:08: No, but then why did some of the founders of the theory seem to think that consciousness and quantum mechanics were inextricably linked.
 00:41: ... behavior of quantum system  rules encapsulated in the mathematics of quantum mechanics. ...
 00:52: ... its stunning success, we are now nearly a century past the foundation of quantum mechanics and physicists are still debating how to interpret its equations and the ...
 01:32: ... we're going to need to go back to one of the earliest interpretations of quantum mechanics  the Copenhagen interpretation, often associated with Neils Bohr and ...
 09:40: ... as Richard Feynman said, "If you think you understand quantum mechanics, you don't understand quantum mechanics." The more you know about this ...
 09:56: And yet the most confident claims about quantum mechanics seem to be the mystical ones.


20200127: Hacking the Nature of Reality
 00:54: ... the birth of modern quantum theory and first complete formulation of quantum mechanics  matrix ...
 01:08: ... representations of quantum mechanics soon followed  for example, the wave mechanics driven by the ...
 01:53: ... its importance in the foundation of quantum mechanics, and being championed by Bohr and Heisenberg, most physicists over the ...
 05:03: In fact, it's still a very important tool in quantum mechanics today.
 09:11: ... Smatrix approach to solving problems in quantum mechanics based on these global consistency conditions and taking advantage of ...


20191209: The Doomsday Argument
 13:11: ... the future of humanity, the nature of space and time, the weirdness of quantum mechanics  you name ...


20191202: Is The Universe Finite?
 12:30: ... this course you can explore the experiments of quantum mechanics and use them to construct equations of motion, laws of physics, and ...


20191021: Is Time Travel Impossible?
 10:54: ... alternative lies in Hugh Everett’s manyworlds interpretation of quantum mechanics, in which every possible universe exists, splitting off in an infinite ...


20191015: Loop Quantum Gravity Explained
 01:09: Back in the day we talked about why combining quantum mechanics with general relativity was so hard.
 01:16: ... example, there’s the fact that general relativity  or perhaps quantum mechanics breaks down when we think about the extreme densities of the black hole ...
 01:46: ... Quantum mechanics, and indeed most theories in physics, involve a set of equations ...
 02:06: In quantum mechanics that stage is flat and static and isn’t influenced by the actors.
 02:18: In short: quantum mechanics is NOT background independent.
 03:30: So just quickly, let’s review all of quantum mechanics.
 03:50: But in quantum mechanics, things aren’t so straightforward.
 04:06: In the first formulations of quantum mechanics, that wavefunction describes the distribution of possible positions and momenta of, say, a particle.
 04:30: ... all, the position and momentum of quantum mechanics literally describes location on a spatial coordinate system and the ...
 04:43: There are other ways to formulate quantum mechanics, like quantum field theory, but these ultimately have the same issue But it gets worse actually.
 04:51: In quantum mechanics, time is treated completely separately to other variables  there is no “time wavefunction” or “time operator”.
 05:19: ... equations of quantum mechanics let you calculate changing properties of a particle  like its position ...
 11:01: ... quantum gravity is that it manages to combine general relativity and quantum mechanics in their currently accepted forms, without taking away their most ...


20190806: What Caused the Big Bang?
 02:14: In the case of inflation part of the appeal is that it fits extremely nicely into our modern understanding of gravity and quantum mechanics.


20190718: Did Time Start at the Big Bang?
 08:52: ... Bang singularity, and just after, GR comes into terrible conflict with quantum mechanics We've talked about that conflict and its possible resolutions before But ...


20190715: The Quantum Internet
 01:00: To understand what needs to be done we need to get to the foundations of quantum mechanics  we need to talk about quantum information theory.
 01:58: ... enjoy all of the weirdness of quantum mechanics  they can be in a superposition of many states at once, defined only ...


20190606: The Alchemy of Neutron Star Collisions
 13:02: ... Grumpy's wavefunction  can't Has Cheezburger just by talking about it quantum mechanics forbids that anyway I'm sure grumpy is now in meme heaven looking down ...


20190516: The Cosmic Dark Ages
 13:07: ... some quantum encryption  ways to secure messages using the weirdness of quantum mechanics. One thing I learned is that you guys already know a lot about classical ...
 14:48: ... cryptography was as a way to describe some of the crazy properties of quantum mechanics. Hopefully we managed to do ...


20190509: Why Quantum Computing Requires Quantum Cryptography
 00:35: ... soon, perhaps very soon, we’ll be interacting with the weirdness of quantum mechanics even more directly – with the coming of quantum computing and the ...
 04:21: Each highlights a different fundamental weirdness of quantum mechanics – the Heisenberg uncertainty principle and quantum entanglement.
 10:40: Another way to generate secure keys using quantum mechanics was developed by Artur Ekert in 1991.


20190410: The Holographic Universe Explained
 02:23: But destroying quantum information would break the foundations of quantum mechanics.


20190403: The Edge of an Infinite Universe
 08:01: That’s handy because flat space is the only space where quantum mechanics is fully solvable.
 14:31: Quantum mechanics in the form of a conformal field theory in one space is a theory of quantum gravity in a space with one higher dimension.


20190306: The Impossibility of Perpetual Motion Machines
 06:50: In fact, quantum mechanics forbids it.


20190124: The Crisis in Cosmology
 16:41: ...and is used in, for example, Feynman's path integral formulation of quantum mechanics.


20190116: Our Antimatter, Mirrored, TimeReversed Universe
 08:43: ... to conserve quantum information which itself is required for all of quantum mechanics to make sense  well to get at this we're going to need to talk about ...
 10:26: ... with Richard Feynman  it's essential to his path integral approach to quantum mechanics and to Feynman diagrams maybe that's why he was so into building ...
 10:54: ... then there's the whole entropy business although it's connection to quantum mechanics is still not well understood like I said this simple interpretation of T ...


20181212: Quantum Physics in a Mirror Universe
 00:02: ... in spacetime and even the rather abstract phase of the wave function in quantum mechanics so it might be surprising to learn that with all the weird ways in which ...


20181107: Why String Theory is Right
 00:06: ... theory as the one great hope for a theory of everything that will unify quantum mechanics and gravity and so unify all of physics into one great, glorious theory ...
 02:50: ... is immune to the main difficulty in uniting general relativity with quantum mechanics. ...
 07:46: A really important type of symmetry in quantum mechanics is gauge symmetry.
 08:54: So in a way, electromagnetism was discovered in its quantum form by studying the symmetries of quantum mechanics.
 14:14: ... week we talked about one of the most misunderstood concepts in quantum mechanics, the idea of virtual particles and their tenuous connection to ...
 16:39: Quantum mechanics can't tell us whether anyone cares.


20181031: Are Virtual Particles A New Layer of Reality?
 08:40: Did I mention that quantum mechanics is weird?
 09:20: ... mode should have 0 energy in a vacuum, but in quantum mechanics, nothing can be so exact thanks, again, to the Heisenberg uncertainty ...


20181010: Computing a Universe Simulation
 02:01: That includes most formulations of quantum mechanics and proposals for theories of everything.
 11:41: ... of physics, in particular very standard ideas on general relativity and quantum mechanics, to figure out the computational properties of our ...


20181003: How to Detect Extra Dimensions
 14:43: ... quickfire answers John Gibbs yes, if general relativity and quantum mechanics are both right, then we should have Plancklength virtual black holes ...


20180920: Quantum Gravity and the Hardest Problem in Physics
 00:00: [MUSIC PLAYING] MATT O'DOWD: Between them, general relativity and quantum mechanics seem to describe all of observable reality.
 00:47: Together, general relativity and quantum mechanics have allowed us to explain nearly every fundamental phenomenon observed.
 01:29: What exactly are the conflicts between general relativity, or GR, and quantum mechanics?
 02:17: Where general relativity describes the universe of the large and the massive, quantum mechanics talks about the subatomic world.
 11:27: Generations of physicists, starting with Einstein himself, spent their lives trying to fix this to unite quantum mechanics and general relativity.


20180905: The Black Hole Entropy Enigma
 02:25: But a fundamental tenet of quantum mechanics is that quantum information can never be destroyed.


20180823: How Will the Universe End?
 15:25: ... the answer is, essentially, that as far as quantum mechanics is concerned, size is a property of composite particles, things that are ...


20180711: Quantum Invariance & The Origin of The Standard Model
 02:31: That's the most basic equation of motion of quantum mechanics.
 04:56: The equations of quantum mechanics have what we call global phase invariance.


20180620: The Black Hole Information Paradox
 00:12: But that same radiation threatens the very foundations of quantum mechanics.
 00:59: The apparent destruction of quantum information by Hawking radiation defies our current understanding of quantum mechanics.
 01:37: We saw that the very foundations of quantum mechanics demand that quantum information be preserved forever.
 07:07: And two, if it did, it would break quantum mechanics as surely as the old information paradox.
 09:29: This led him to realize that the union of quantum mechanics and gravity may require that the entire 3D universe be a projection on a 2D structure.


20180613: What Survives Inside A Black Hole?
 10:31: We discussed recently why quantum mechanics demands the conservation of quantum information.
 10:37: It's fundamental to quantum mechanics that the universe keeps track of its quantum states, which also means the types of particles it contains.
 11:44: In our last episode we looked at what might be the most fundamental rule in quantum mechanics, the conservation of quantum information.


20180523: Why Quantum Information is Never Destroyed
 00:36: Newton's equations for classical mechanics, Maxwell's equations for electromagnetism, and the Schrodinger equation for quantum mechanics.
 01:16: Today, we learn why conservation of information is such a fundamental requirement of quantum mechanics.
 04:33: Actually, quantum mechanics forbids this.
 04:45: To get at this, let's think about the basic equation of motion of quantum mechanics.
 05:02: ... in quantum mechanics, that means the probability distribution of all of its properties, which ...
 05:51: ... the conservation of information, as do the more advanced formulations of quantum mechanics, like the Dirac equation and quantum field ...
 06:49: And this unitarity is a foundational assumption in all formulations of quantum mechanics and quantum field theories.
 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.
 08:41: ... the collapse of the wave function in the Copenhagen interpretation of quantum mechanics actually does mess with conservation of ...
 09:14: ... interpretations of quantum mechanics, for example, Everett's manyworlds or the de BroglieBohm pilot wave ...
 09:43: There is one situation where timereversibility appears to be broken regardless of your favorite interpretation of quantum mechanics.


20180516: Noether's Theorem and The Symmetries of Reality
 06:43: ... of classical mechanics to Feynman's path integral formulation of quantum mechanics. ...
 09:01: ... Weyl, also a giant in the mathematical foundation of quantum mechanics, said in her memorial address, I was ashamed to occupy such a preferred ...


20180404: The Unruh Effect
 01:19: To understand this, we don't need general relativity with its spacetime curvature and conflicts with quantum mechanics.


20180315: Hawking Radiation
 01:31: ... this and in a followup 1975 paper, he attempted a new union of quantum mechanics and general relativity to show that black holes should not be so black ...
 04:35: To answer that properly, he would need a full union of general relativity and quantum mechanics, a theory of quantum gravity, a theory of everything.
 06:06: But to understand the effect of the close encounter with the black hole, he required an uneasy marriage of quantum mechanics and general relativity.


20180228: The Trebuchet Challenge
 03:04: We could get into fluid or stellar dynamics, or even quantum mechanics.


20180214: What is Energy?
 08:43: The concept of energy is so versatile that Hamilton's approach was even adapted to quantum mechanics.
 09:19: Lagrangian mechanics is the inspiration behind Feynman's path integral approach to quantum mechanics.


20180117: Horizon Radiation
 00:00: ... The most successful theory in physics combines the weirdness of quantum mechanics with, well, the weirdness of special relativity, to give quantum field ...
 14:17: It feels like it's in the family of, we don't understand it, so it must be quantum mechanics.


20171206: Understanding the Uncertainty Principle with Quantum Fourier Series
 00:07: Sometimes intuitive, largescale phenomena can give us incredible insights into the extremely unintuitive world of quantum mechanics.
 00:28: [MUSIC PLAYING] One of the most difficult ideas to swallow in quantum mechanics is Werner Heisenberg's famous uncertainty principle.
 00:44: We've discussed it in earlier videos on quantum mechanics, but it's time we looked a little deeper.
 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.
 02:24: See, quantum mechanics is a type of wave mechanics.
 06:49: In the early days of quantum mechanics, it was realized that photons are electromagnetic wave packets whose momentum is given by their frequency.
 10:12: So what does this oldschool quantum mechanics have to do with quantum field theory and Hawking radiation?
 11:59: ... yourself even better, you could check out Benjamin Shoemaker's series, "Quantum Mechanics," which includes a great episode on the uncertainty ...


20171102: The Vacuum Catastrophe
 04:12: In fact, in both quantum mechanics and classical mechanics, a particle's equations of motion depend only on changes in energy.


20171011: Absolute Cold
 01:11: But quantum mechanics may also prevent us from ever reaching absolute zero.
 04:59: However, the most fundamental law of quantum mechanics forbids this.


20170920: The Future of Space Telescopes
 12:14: Basically, the electrons are crammed as close together as quantum mechanics allows.


20170810: The OneElectron Universe
 01:46: ... path integral formulation and the following spacetime interpretation of quantum mechanics, which won him the 1965 Nobel Prize in ...


20170726: The Secrets of Feynman Diagrams
 00:42: ... to Feynman's approach to quantum mechanics, every conceivable happening that leads from a measured initial state to ...


20170712: Solving the Impossible in Quantum Field Theory
 13:35: So the deal is that Schrodinger's equation is a special case of a more general formulation of quantum mechanics.


20170707: Feynman's Infinite Quantum Paths
 00:00: ... PLAYING] Quantum mechanics seems to imply that all possible properties, paths, or events that could ...
 00:13: ... description of this crazy idea led to the most powerful expression of quantum mechanics ever devised Richard Feynman's path integral ...
 01:46: There's a story about a quantum mechanics professor explaining the doubleslit experiment to a class.
 02:45: And he'd just outlined the basics of what was to become the path integral formulation of quantum mechanics.
 02:53: But it led to the most elegant formulation of quantum mechanics ever devised and became a key to quantum field theory.
 04:28: From that, it was possible for him and others to rederive all of quantum mechanics.
 07:51: ... equivalent to and more powerful than earlier derivations of quantum mechanics. ...
 08:37: But Feynman's solution produced a quantum mechanics that didn't need fixing.


20170628: The First Quantum Field Theory
 00:24: [MUSIC PLAYING] Quantum mechanics is perhaps the most unintuitive theory ever devised.
 00:41: Simply by following the math of quantum mechanics, incredible discoveries have been made.
 00:46: Its wild success tells us that the mathematical description provided by quantum mechanics reflects deep truths about reality.
 00:55: And by far the most successful, most predictive formulation of quantum mechanics is quantum field theory.
 04:56: However, the first full formulation of quantum mechanics was Schrodinger's equation and it couldn't account for light at all.
 06:32: But bean counting in this way is not just inefficient in quantum mechanics.
 12:45: ... you want to learn more about the relationship and the conflict between quantum mechanics and relativity, check out the course, The Theory of Everything, by ...
 14:26: ... 100 asks, "Why was it possible to make quantum mechanics compatible with special relativity when we're still struggling to ...


20170621: AntiMatter and Quantum Relativity
 00:24: And the emerging field of quantum mechanics had radically altered our understanding of the fundamental building blocks of the universe.
 05:55: It contains the marks of both quantum mechanics, in the Planck constant, and relativity, in the speed of light.
 10:53: ... incredible insight in combining quantum mechanics and relativity reveal an entire flip side of our universe, with its ...


20170503: Are We Living in an Ancestor Simulation? ft. Neil deGrasse Tyson
 14:04: The truth of that statement depends on which interpretation of quantum mechanics you want to go with.


20170315: Time Crystals!
 09:08: Time crystals could also help bridge the gap between quantum mechanics and general relativity.
 09:21: And unlike in relativity, quantum mechanics treats space and time very differently to each other.


20161208: What Happens at the Event Horizon?
 19:07: Personally, I'm agnostic towards the relative truth behind the Copenhagen, manyworlds, pilot wave, or the other interpretations of quantum mechanics.


20161130: Pilot Wave Theory and Quantum Realism
 00:00: ... PLAYING] There is one interpretation of the meaning of quantum mechanics that somehow manages to skip a lot of the wildly extravagant or ...
 00:26: ... PLAYING] Misinterpretation of the ideas of quantum mechanics has spawned some of the worst quackery pseudoscience hooha and ...
 00:47: There are some pretty out there explanations for the processes at work behind the incredibly successful mathematics of quantum mechanics.
 01:19: But there is one interpretation of quantum mechanics that remains comfortably, almost stodgily, physical.
 01:47: Pilotwave theory is perhaps the most solidly physical, even mundane, of the complete and selfconsistent interpretations of quantum mechanics.
 02:08: And the founding fathers of the Copenhagen interpretation of quantum mechanics Niels Bohr and Werner Heisenberg were radicals.
 04:13: That's the equation at the heart of all quantum mechanics that tells the wave function how to change across space and time.
 04:21: This means that pilotwave theory makes the same basic predictions as any other breed of quantum mechanics.
 06:21: See, although pilotwave theory makes all of the usual predictions of quantum mechanics, it has some really fundamental differences.
 08:00: But hidden variables have a bad rap in quantum mechanics.
 11:33: Now let's not even start talking about gravity no version of quantum mechanics has that sorted out.
 11:55: ... it shows us that it's possible to have a consistent interpretation of quantum mechanics that is both physical and deterministic, no hooha ...


20161109: Did Dark Energy Just Disappear?
 13:17: I want to respond to some of your thoughts on both colonizing Mars, as well as on the Many Worlds interpretation of quantum mechanics.


20161026: The Many Worlds of the Quantum Multiverse
 00:09: A huge outstanding question is when and why does the weirdness of quantum mechanics give way to classical physics.
 01:24: Quantum mechanics very successfully predicts this result by describing each particle's journey as a superposition of all possible trajectories.
 02:04: ... the original Copenhagen interpretation of quantum mechanics, the act of measurement was thought to collapse possibility space into a ...
 02:24: One of the founders of quantum mechanics, Erwin Schrodinger, found this ridiculous.
 05:52: This sounds outrageous, but it's a very serious interpretation of the mathematics of quantum mechanics.
 08:18: ... may, in fact, be the more pure interpretation of the mathematics of quantum mechanics because there's nothing in that math that requires the collapse of the ...
 08:29: ... is more economical in the number of unsupported concepts it adds to quantum mechanics, even if it isn't particularly economical in the number of universes it ...
 09:29: There's no more evidence for many worlds than there is for other mainstream interpretations of quantum mechanics.
 09:47: ... so although it is supported by the incredibly successful mathematics of quantum mechanics, it has not yet added a prediction that might distinguish it from other ...
 10:23: It explains the apparent randomness of quantum mechanics with a sort of observer bias.


20160929: Life on Europa?
 09:57: ... between the predictions of a local hidden variable theory versus pure quantum mechanics is if you measure the spins of both particles with the same measurement ...
 11:18: The definition of observer sort of depends on what interpretation of quantum mechanics you're going with.


20160921: Quantum Entanglement and the Great BohrEinstein Debate
 00:25: But they're actually surprisingly good at quantum mechanics.
 01:27: But quantum mechanics is so bizarre that it still has scientists wondering if we need to reject even this basic premise.
 01:34: This was the source of one of the most heated debates at the advent of quantum mechanics.
 02:29: He insisted that the wave function, and by extension quantum mechanics, is incomplete.
 03:13: The Einstein Podolsky Rosen, or EPR, paradox introduces one of the most mysterious ideas in quantum mechanics quantum entanglement.
 03:36: ... Quantum mechanics requires that we describe the particle pair with a single combined wave ...
 05:10: But in quantum mechanics, measurement actually affects the thing you are measuring.
 07:13: ... that we'd expect to see in the case that Einstein was right and quantum mechanics needs local hidden ...
 09:09: Are babies really better at quantum mechanics than Einstein?


20160907: Is There a Fifth Fundamental Force? + Quantum Eraser Answer
 06:59: But there's still time for a minirant about the role of consciousness in quantum mechanics.


20160810: How the Quantum Eraser Rewrites the Past
 06:26: This is quantum mechanics.


20160727: The Quantum Experiment that Broke Reality
 06:00: ... function." Describing the behavior of the wave function is the heart of quantum mechanics. ...
 07:42: In fact, the answers aren't known but the various interpretations of quantum mechanics do try.
 07:49: Let's talk about the view favored by Werner Heisenberg and Niels Bohr, who pioneered quantum mechanics at the University of Copenhagen in the 1920s.
 09:36: ... theory of quantum mechanics produces stunningly accurate predictions of reality and it's completely ...
 10:50: I have recently been exploring The Great Courses Plus quantum mechanics content.


20160720: The Future of Gravitational Waves
 06:49: And that's actually close to the number you get from doing this with quantum mechanics so that's cool.


20160706: Juno to Reveal Jupiter's Violent Past
 11:33: A few of you rightly know that quantum mechanics isn't needed to resolve Zeno's paradox of Achilles and the tortoise.


20160629: Nuclear Physics Challenge
 00:06: We've been talking about quantum mechanics recently, and I think we're ready to do a bit of recreational nuclear physics.


20160615: The Strange Universe of Gravitational Lensing
 10:54: ... of possible locations is only true for the Copenhagen interpretation of quantum mechanics. ...
 12:30: Mystyc Cheez and others ask, what is really meant by an observation in quantum mechanics?


20160601: Is Quantum Tunneling Faster than Light?
 00:08: According to quantum mechanics you are, at least a little bit.
 00:12: [THEME MUSIC] Quantum mechanics is a spectacularly weird theory.
 07:04: To make that work you need to use a second, and perhaps even weirder feature of quantum mechanics, quantum entanglement.


20160302: What’s Wrong With the Big Bang Theory?
 04:20: See, at this point, general relativity comes into serious conflict with quantum mechanics.


20151209: How to Build a Black Hole
 00:06: To make one, we need both general relativity and quantum mechanics.
 01:04: We need quantum mechanics.
 05:17: The details may be a topic for another episode, but in short, quantum mechanics describes matter as a distribution of possibilities.
 05:55: This is the weirdest, coolest aspect of quantum mechanics.


20151028: Is The Alcubierre Warp Drive Possible?
 04:04: Except Stephen Hawking chronology protection conjecture states that quantum mechanics will always stop causalitybreaking actions.
 04:13: It suggests that there's something in the deeper union of GR and quantum mechanics, the theory of everything, that prohibits the warp drive.
 08:32: Quantum mechanics began as an abstract musing on the nature of reality.


20150805: What Physics Teachers Get Wrong About Tides!
 11:41: ... field theory versions of something and then add to them the machinery of quantum mechanics to sort of get a quantized version of the ...


20150429: What's the Most Realistic Artificial Gravity in SciFi?
 10:30: Does quantum mechanics bring back free will since it attaches some inherent randomness to the future.
