
20221123: How To See Black Holes By Catching Neutrinos
 02:18: ... be challenging, given that each neutrino has a minuscule interaction probability most of them pass straight through your ...


20221019: The Equation That Explains (Nearly) Everything!
 03:24: ... we’re calculating the path traveled by a ball through the air or the probability that two quantum particles will ...


20220928: Why Is 1/137 One of the Greatest Unsolved Problems In Physics?
 05:34: Those probabilities depend on many things, like the particles’ positions and momenta, spins, charges, masses, etc.
 05:42: These factors multiply a sort of base probability to make the interaction more or less likely.
 05:49: That base probability comes from the coupling constant or coupling strength for the interaction.
 06:02: ... square of alpha is the base probability that an electron will emit or absorb a photon, or in the case of two ...


20220824: What Makes The Strong Force Strong?
 12:57: ... combos appears to cancel out, but it's not really neutral because the probability of the green interaction is double the other ...


20220803: What Happens Inside a Proton?
 03:12: ... gives us a recipe book for adding up the probabilities. We talked about this stuff in some previous videos. But ...
 04:17: ... of QED. As the interactions get more complicated, their probabilities get smaller and smaller. Diagrams with more than a few twists and ...
 05:31: ... now with curly gluon lines. Presumably then to calculate the probability of a given interaction we again just add up diagrams, ...
 06:02: ... Feynman diagrams when you’re calculating the interaction probability for your pair of quarks. Adding new vertices doesn’t ...
 07:53: ... the starting and final field configuration to get the probability of that transition ...
 08:58: ... we understand exactly what we’re trying to do here. We want the probability for some wiggly quantum field wiggles between ...
 10:43: ... more likely than others. In the Feynman path integral, the probability of each path comes from adding up all the little shifts in the ...
 12:15: ... connections are the gluon field. Getting rid of the quantum probabilities means this isn’t really even a quantum problem any ...


20220720: What If We Live in a Superdeterministic Universe?
 02:20: ... block of reality is the wavefunction, which describes the evolving probability distribution of all possible properties of the world, or of tiny parts ...


20220622: Is Interstellar Travel Impossible?
 05:26: This impact probability is way too high to be acceptable.


20220615: Can Wormholes Solve The Black Hole Information Paradox?
 07:24: ... you, the Richard Feynman’s path integral calculates the probability of some quantum particle traveling between two points by ...


20220601: What If Physics IS NOT Describing Reality?
 11:24: ... as pretty fundamental. It describes the evolving distribution of probabilities for the results you might get if you tried to measure ...
 15:25: ... Given that most of the galaxy is empty space, what’s the probability of stars colliding? Well for any given star the chance is ...


20220518: What If the Galactic Habitable Zone LIMITS Intelligent Life?
 11:12: ... of star formation and folded in estimates for the probability of the emergence of planets based on heavy element ...


20220112: How To Simulate The Universe With DFT
 00:54: ... ol’ Schrodinger equation on the blackboard and solve it to learn the probability distribution of the electron locations, or the energy levels of the ...
 02:19: ... find the wavefunction, and the square of that wavefunction gives the the probability distribution for where you’ll find the electron if you try to measure ...


20211210: 2021 End of Year AMA!
 00:02: ... interactions gives you the interaction that actually happens or the probability distribution of that interaction so each in that context every ...


20211013: New Results in Quantum Tunneling vs. The Speed of Light
 13:59: ... goes through solid bedrock so there’s a low probability that your quantum wavefunction will make it through  but if you do then ...


20210921: How Electron Spin Makes Matter Possible
 05:59: ... A wavefunction is this thing that holds information about the probability of a given property being observed. For example, the wavefunction ...
 08:00: ... state of an electron. We’ll call it Psi. Psi gives the distribution of probabilities of some observable  for example, the location of the electron around ...
 08:21: ... actual probability distribution is the square of that. We can never, ever observe Psi  all ...


20210907: First Detection of Light from Behind a Black Hole
 15:54: ... I would also imagine that the bigger the energy difference, the less probability of the field tunneling to the true minimum, so maybe those cancel ...


20210818: How Vacuum Decay Would Destroy The Universe
 10:10: ... it’s inevitable. At any instant in time there’s a tiny but real probability that a patch of space will tunnel between the false and ...


20210721: How Magnetism Shapes The Universe
 16:05: Each infinitesimal location can be thought of as a “world” and some worlds have more weight  more probability than others.
 16:46: A related point is regarding probability.
 16:49: ... world per option, then what does that mean for the different weights  probabilities of those different wavefunction ...
 17:10: ... probabilities must be reflected in the number of worlds for each quantum outcome  ...
 17:25: If the splitting only made one world per distinct outcome then indeed probability would be destroyed.
 17:31: ... see differences in likelihood, and therefore probability is not destroyed, so IF the many worlds explanation is right then the ...


20210713: Where Are The Worlds In Many Worlds?
 03:46: Where a pond ripple is an oscillation in surface height, the wavefunction is an oscillation in probability, or more accurately probability density.
 07:57: ... high and low points in the wavefunction  meaningful blips in the probability ...


20210707: Electrons DO NOT Spin
 07:30: ... describes how quantum objects behave as evolving distributions of probability  as wavefunctions.It was proving amazingly successful at ...


20210623: How Quantum Entanglement Creates Entropy
 06:38: ... we call the wavefunction  that’s the distribution of probabilities of all the possible properties the system could have if you tried ...


20210519: Breaking The Heisenberg Uncertainty Principle
 07:35: ... the xaxis and amplitude is plotted on the yaxis—as a fuzzy circle of probability, where the area of the circle is proportional to Planck’s constant, ...
 08:03: ... in the opposite dimension, so that the total area of this squeezed probability disk remains the ...


20210421: The NEW Warp Drive Possibilities
 14:18: The probability that a particle will interact with other massive virtual particles is proportional to the square of that particle’s own mass.


20210407: Why the Muon g2 Results Are So Exciting!
 08:19: The probability of interaction between a particle and some massive virtual particle is proportional to mass squared.


20210323: Zeno's Paradox & The Quantum Zeno Effect
 02:44: Rather, each state has an amplitude that determines the probability of finding the arrow in that state were you to try to observe it.
 02:58: ... to that observation, the arrow exists as just the distribution of probability amplitudes of its position; its wavefunction is spread between the start ...
 04:34: But because you start watching it close to the beginning of its journey, there’s very little probability of it collapsing to the end.


20201104: Electroweak Theory and the Origin of the Fundamental Forces
 04:50: ... try an example: In quantum mechanics, the wavefunction determines the probabilities of certain outcomes being measured for observables like particle ...
 06:49: The ‘U’ stands for unitary and tells us that elements of this group preserve vector length, or in our case quantum probability.


20201020: Is The Future Predetermined By Quantum Mechanics?
 02:53: ... as well defined reality but rather as distributions of probability that describe all possible states that, that chunk of the universe could ...


20200928: Solving Quantum Cryptography
 06:35: ... give an output, are in a quantum superposition of 0 and 1, with some probability of either being measured when you try to read out the ...
 06:48: ... and each state represents a different number, each with a different probability. ...


20200728: What is a Theory of Everything: Livestream
 00:00: ... has gone horribly wrong you know things like infinite energies or probabilities greater than one these kinds of things indicate that there's something ...


20200630: Dissolving an Event Horizon
 14:17: ... have something called an interaction crosssection, which defines the probability of another particle interacting with the electron as a function of ...
 14:40: ... both space and time by the same factor, you also rescale the interaction probabilities to that the interaction rate scales in the same way ... So a pair of ...


20200316: How Do Quantum States Manifest In The Classical World?
 17:40: ... result of that measurement. And the wavefunction itself defines the probability of a given branch "collapsing". The Many Worlds interpretation states ...


20200303: Does Quantum Immortality Save Schrödinger's Cat?
 09:36: ... some people used much more sophisticated probability arguments including Bayesian analysis or thinking in “observer years” ...
 09:46: But none of that helped  the probability for humanity's survival to the year 3000 remained at about a percent or lower.


20200224: How Decoherence Splits The Quantum Multiverse
 02:34: ... probability for a system going from one state to another can be calculated by ...
 03:38: ...  a quantum particle seems to pass through two slits simultaneously as a probability wave that ultimately “collapses” to leave it as a single position on a ...
 04:28: The probability of the photon having reached this particular spot is determined by the sum of all possible trajectories to that spot.
 04:57: Because the wavefunction is amplified at that spot, there’s a high probability of the particle landing there.
 05:22: That’s destructive interference and the probability of the particle ending up there goes to zero.


20200218: Does Consciousness Influence Quantum Mechanics?
 02:51: Instead it travels as an abstract “probability wave”  something we call a wavefunction.
 02:58: That probability wave defines the location of the electron at any point IF you try to measure it.
 03:34: ... seems essential because our largescale, classical world isn’t made of probability clouds, it’s made of objects with clearly definable ...


20200203: Are there Infinite Versions of You?
 02:39: But one of those monkeys will correctly complete Cymbeline and all of Shakespeare’s First Folio with a probability of 1/100^3.75 million.
 02:58: This is an unthinkably small probability.
 03:01: ... it’s not zero probability, and the Infinite Monkey Theorem tells us that any nonzero probability ...
 03:57: ... probability of getting every particle just right is unthinkably smaller than the ...
 04:06: ... it’s not a zero probability, and so with infinite regions of the universe  infinite trials, the ...


20200127: Hacking the Nature of Reality
 04:44: The Smatrix is a map of the probabilities of all possible outgoing particles, or outstates, for a given set colliding particles  instates.


20200120: Solving the Three Body Problem
 10:30: ... for a pseudorandom system, statistical mechanics lets us calculate the probability of the system being in any part of that phase space at any one ...


20191217: Do Black Holes Create New Universes?
 16:35: Well, from the Prince of France's perspective, the answer to that question is a probability of 1.
 16:41: From everyone else's perspective, the answer is a probability of 0.
 17:11: ... you ask him for the probability that he's the Prince of France he should probably say 1 in 33 million, ...


20191209: The Doomsday Argument
 08:01: In fact we can use statistics to estimate the probability of our species lasting a certain amount of time.


20191118: Can You Observe a Typical Universe?
 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: ... status as observers when we interpret our environment  including the probability of being in ...
 08:21: ... from a high entropy state, then the lower the entropy the less probability of that region ...
 10:47: We should take into account what we already know  our “priors”  before assessing any probabilities.


20191104: Why We Might Be Alone in the Universe
 11:40: ... events were phenomenally unlikely  we simply can’t assign them larger probabilities until we get more evidence  which ideally means seeing them happen more ...


20191007: Black Hole Harmonics
 13:12: ... levels of science you’re going to need to have a solid understanding of probability. ...
 13:24: Brillaint.org has a new course on probability fundamentals that include interactive challenges and problems to solve.
 13:35: You can Learn probabilistic basics, such as fairness, expected value, and symmetry, in their course Probability Fundamentals.


20190930: How Many Universes Are There?
 03:05: We assumed that there’s a fixed but unknown probability that a bubble universe will form in any given volume of inflating space.
 04:51: This gives us a ridiculously large number of universes even if the probability of making one per unit of volume is insanely low.
 11:29: He proposes that there may be something off in the logic of weighing up probabilities over bubble universes.


20190806: What Caused the Big Bang?
 11:51: ... in order for inflation to last long enough to do its job, the probability for the appearance of a bubble can't be too high and that rules out ...


20190701: Thorium and the Future of Nuclear Energy
 02:49: ... U235 is useful because it's highly fissile which means it has a high probability of intercepting a stray Neutron and splitting It's fissile in the ...


20190509: Why Quantum Computing Requires Quantum Cryptography
 08:07: ... random result – Albert sends a 1 but Niels will get a 1 or 0 with equal probability. ...


20190207: Sound Waves from the Beginning of Time
 13:26: ... expands towards the infinite future, does that expansion outpace the probability of collapsing into a big crunch due to everything quantum tunneling ...


20181121: 'Oumuamua Is Not Aliens
 14:47: This in turn changes the probabilities of oscillation and suppresses oscillations to tau neutrinos.


20181114: Supersymmetric Particle Found?
 10:13: The probability of a chance association with a supernova is around 3%, so it's unlikely but it does happen.


20181031: Are Virtual Particles A New Layer of Reality?
 15:15: The Fermi paradox must be explained by a very long chain of soft filters that add up to extremely small probability or one or more hard filters.


20181025: Will We Ever Find Alien Life?
 11:46: Depending on the destruction probability let's call it the wacko factor you might expect civilizations to last from decades to thousands of years.
 12:22: I guess it depends on the relative probabilities.


20180920: Quantum Gravity and the Hardest Problem in Physics
 02:41: That math started with the Schrodinger equation, which tracks these probability waves through space and time.


20180912: How Much Information is in the Universe?
 14:27: ... radioactive elements, but can be used for anything that has a constant probability of decaying in a given amount of ...
 14:43: The actual amount of time it takes to decay is random, and there's a constant probability of it happening at every set interval.


20180823: How Will the Universe End?
 15:43: All they have is their quantum wave function, which tells the probability of the particle's location, momentum, spin, direction, et cetera.
 15:56: But that spatial sprint really just tells us the probability of finding the electron, say, here or here or here.


20180725: Reversing Entropy with Maxwell's Demon
 12:13: If different microstates can have different probabilities, then you need to include those probabilities in your equation for entropy.


20180718: The Misunderstood Nature of Entropy
 11:11: Stunningly, its foundations are in probability theory.
 11:16: To really get stat mech, you have to get probability.
 11:20: Brilliant.org has a great course on probability that's solidly founded on exercisebased learning.


20180711: Quantum Invariance & The Origin of The Standard Model
 03:11: The square of the magnitude of this wave function tells us the probability distribution of a particle's position.
 05:56: That shouldn't change our probabilities for the positions of the particles, but what about observables besides positions?


20180613: What Survives Inside A Black Hole?
 11:57: How is probability conserved when an electron and a positron annihilate each other?
 12:18: ... by quantumfield theory, and unitary evolution and the conservation of probability and information still works ...
 12:34: Now it's the evolution of the fields, not the particles, that conserves probability.
 13:06: ... wave function prescribes the probability of observing a given value for a property when the observation is made, ...


20180523: Why Quantum Information is Never Destroyed
 04:36: It ensures conservation of information and timereversal symmetry because of an even more fundamental rule the conservation of probability.
 05:02: ... in quantum mechanics, that means the probability distribution of all of its properties, which you can get by taking the ...
 05:10: ... example, the wave function of a particle encapsulates the probability that it will be found in this or that location if we were to try to ...
 06:10: Remember that the wave function encapsulates the distribution of probabilities for a given property.
 06:15: By definition, those probabilities should add up to 1.
 06:19: But that just means there's 100% probability that any given property will have some possible value, even if that value is zero.
 06:27: In the case of particle position, probability of adding to 1 just means that the particle is definitely somewhere.
 06:39: The probabilities should continue to sum to 1.
 06:56: ... is a nonnegotiable statement about how probability works, but the condition also ensures timereversal symmetry and ...
 07:05: ... states must remain independent of each other in order to preserve probability. ...
 07:21: If they did, then the probabilities for the initial states or for the final state can't both sum to 1.
 07:27: ... quantum states A and B can't both become quantum state C. The sum of the probabilities prior to the merger would not equal the sum of the probabilities after ...
 07:41: The only type of evolution that preserves probability and unitarity is the evolution that also preserves the number of quantum states.
 08:12: That value seems to be chosen randomly based on the probability distribution encoded in the wave function.


20171206: Understanding the Uncertainty Principle with Quantum Fourier Series
 08:06: The magnitude of the wave function squared is the probability distribution for the particle.


20170726: The Secrets of Feynman Diagrams
 00:19: ... MUSIC] Feynman's path integral shows us that to properly calculate the probability of a particle traveling between two points, we need to add up the ...
 00:57: To calculate the probability of any quantum system evolving between two states, we need to sum over every conceivable intermediate state.
 01:27: ... needed to calculate the contribution of that family to the total probability. ...


20170719: The Real Star Wars
 16:37: A few of you asked why it is that each additional vertex reduces the probability contribution of a given Feynman diagram by around a factor of 100.
 16:57: The probability of that interaction is governed by the coupling constant between those fields.
 17:07: In fact, the probability amplitude added at each vertex is proportional to the square root of the fine structure constant.
 17:15: The probability itself is the square of the probability amplitude.
 17:28: ... the electron field, so every additional vertex, another one of these 1% probability events has to ...


20170712: Solving the Impossible in Quantum Field Theory
 06:38: Every other way to scatter the electrons contributes less to the probability of the event.
 06:50: It turns out that the probability amplitude of a particular interaction depends on the number of connections, or vertices, in the diagram.
 06:59: Every additional vertex in an interaction reduces its contribution to the probability by a factor of around 100.
 07:17: A threevertex interaction would contribute about 1% of the probability of the main twovertex interaction.
 07:56: And more complicated interactions add even less to the probability.
 14:10: [INAUDIBLE] points out that the final probability for a particle journey is the square of the length of the complex probability amplitude vector.
 14:20: Probability is the square of the probability amplitude.
 14:25: ... the sense I wanted to relay is that the total probability depends on the length of the summed probability amplitudes so the ...
 14:37: ... also correctly points out that the individual paths don't have different probability amplitude lengths taken separately, but rather, they're pointing in the ...
 15:06: ... applying the principle of least action in the determination of probability amplitudes, it turns out that the "crazy" paths, including the ...


20170707: Feynman's Infinite Quantum Paths
 01:27: ... that fills the intervening space interacts with itself and defines the probability of that particle actually showing up at a given point on the ...
 03:40: ... out a way to combine the infinite paths to give a very real finite probability of a particle reaching its final ...
 05:33: ... the contributions from all of those infinite possible paths to find the probability of a particle making that simple journey from A to ...
 05:46: Feynman's paths don't each have some separate probability of occurring.
 05:50: Instead, each path contributes what we call a probability amplitude to the entire AB journey.
 05:58: Schrodinger's wave function and Feynman's path integral describe this probability amplitude thing.
 06:05: Now, regular probabilities are normal positive numbers between 0 and 1.
 06:10: However, probability amplitudes are what we call complex numbers.
 06:15: We can think of each path's probability amplitude as a vector or an arrow of a certain length and direction in an imaginary 2D space.
 06:26: The total length of each arrow gives the probability of that path being taken.
 06:32: But to get the total probability that a particle travels from A to B, you connect the probability amplitude arrows for all possible paths end to end.
 06:44: The length of the arrow connecting the start and the end of this chain represents the total probability from all paths.
 06:52: But if two parts contribute individual probability amplitudes that point in exactly opposite directions, they cancel each other out.
 07:13: Now, when Feynman used this action quantity to figure out the probability amplitudes of his infinite paths, something amazing happened.
 07:27: Only the most sensible paths, those with the least action, added significantly to the probability.
 10:04: The quantum action principle gives the probability amplitude of changes in the state of the field.
 10:10: ... includes motion of the photon, but it also includes the probability amplitude of a photon's energy moving from the electromagnetic field ...
 11:04: In fact, they lead to rampant, uncontrolled infinite probabilities.


20170628: The First Quantum Field Theory
 06:38: ... event or interaction can happen in multiple different ways and the probability of the interaction depends on correctly counting those different ...
 07:03: That means you get the wrong probabilities.


20170503: Are We Living in an Ancestor Simulation? ft. Neil deGrasse Tyson
 11:03: He posits a type of Bayesian reasoning, so assessing the probability of the hypothesis being true by taking into account prior probabilities.
 11:12: ... producing the most brains, because that universe would give the maximum probability of our own existence, which is the one thing we know for sure is ...
 16:13: It's also possible to imagine this happening randomly, albeit with stunningly low probability.


20170426: Are You a Boltzmann Brain?
 09:25: ... idea of Boltzmann brains is as a lesson in caution caution in arguing probabilities before really understanding the prior ...


20170315: Time Crystals!
 11:47: That gives you an idea of the average probability of alignment, but not all of those will have planets.


20161221: Have They Seen Us?
 10:50: Simple probability says that any other civilization is likely to be ahead of us on the curve.


20161130: Pilot Wave Theory and Quantum Realism
 02:27: One aspect of that radical thinking was that the wave function is not a wave in anything physical but an abstract distribution of probabilities.


20161102: Quantum Vortices and Superconductivity + Drake Equation Challenge Answers
 02:52: I asked you to figure out some probabilities regarding the existence of other technological civilizations in our galaxy.
 03:24: ... region  that's "N (sub) ast" for "astrophysical factor"  times the probability that a technological civilization will form on any given habitable ...
 05:25: So I'd take that as a very crude estimate of the maximum probability for Earth to have developed us.
 05:38: Probably it's lower, though. Frank and Sullivan lowballed the probability and set the "A" value as 0.01, instead of 1.


20161026: The Many Worlds of the Quantum Multiverse
 00:44: Instead, they seem to behave as probability clouds of all properties they might have were we to try to measure them.
 10:02: ... coherent histories interact or why the wave function translates to probabilities the way it ...


20161005: Are We Alone? Galactic Civilization Challenge
 04:13: If the true probability of producing civilizations is higher, then there have been and perhaps still are advanced species in our galaxy.
 04:38: ... on any habitable planet within 100 light years, how low would that probability of technological emergence need to ...


20160810: How the Quantum Eraser Rewrites the Past
 01:19: It's a probability wave that does all the usual wavelike stuff like making interference patterns, until something happens to collapse it.


20160803: Can We Survive the Destruction of the Earth? ft. Neal Stephenson
 11:15: ... suggests that the wave function is nothing more than a distribution of probabilities, and that when the wave function collapses, the properties of the ...


20160720: The Future of Gravitational Waves
 05:41: ... our last challenge question, we asked you to calculate the probability that an alpha particle so a package of two protons and two neutrons ...
 06:09: All those individual probabilities combine to give you a 50% chance of decay after 0.3 microseconds.


20160629: Nuclear Physics Challenge
 01:34: The challenge for today is for you to figure out the tunneling probability for an alpha particle to escape from a polonium 212 nucleus.
 02:04: ... need to find the tunneling probability for each one of these encounters with the wall a probability that will ...
 03:04: ... of your own diagrams, plus some basic algebra is enough to get you the probability that an alpha particle will tunnel out of the polonium 212 nucleus on ...


20160615: The Strange Universe of Gravitational Lensing
 11:37: Prior to that, it exists only as its wave function, which is a distribution of probabilities of these properties.
 11:45: ... description of things as probabilities works, but it's also not deterministic in that in order for the wave ...
 12:16: The wave function that we calculate defines the probability that we will observe a particular set of physical properties.


20160601: Is Quantum Tunneling Faster than Light?
 00:35: Each specific state has a certain probability of being true when the object is observed.
 00:52: There is a distribution of probabilities for each of an object's quantum properties.
 01:39: It can be described as a wave packet of positioned probability.
 04:10: There remains a tiny tail of probability outside the nucleus, beyond the reach of the strong nuclear force.


20151118: 5 Ways to Stop a Killer Asteroid
 02:47: But small probabilities have a way of adding up to a certainty, over time.


20150318: Can A Starfox Barrel Roll Work In Space?
 07:22: I wanted them to be based on understand physics that had some nonmicroscopic probability of occurring.
 08:24: The probability is near zero, way lower than one in a billion.
 08:28: ... so much empty space between star systems and galaxies that the probability of any two of them colliding would be similar to the probability of two ...


20150218: Is It Irrational to Believe in Aliens?
 00:33: With probability statistics, we just need to get a handle on the factors at play in the emergence of intelligent life as we know it.
 01:08: Multiply these two probabilities by the 200 billion planets and, voila, you know how many Wookies, or Covenant, or Vulcans you should expect.
 01:30: Whenever anyone, even a scientist, quotes a number for the "probability" of life arising, it's pretty much a complete guess.
