PBS Space Time

PBS Space Time PBS Space Time

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Space Time explores the outer reaches of space, the craziness of astrophysics, the possibilities of sci-fi, and anything else you can think of beyond Planet Earth with our astrophysicist host: Matthew O’Dowd.
Episodes released every Wednesday afternoon!
Matt O'Dowd spends his time studying the universe, especially really far-away things like quasars, super-massive black holes, and evolving galaxies. He uses telescopes in space to do it. Matt completed his Ph.D. at NASA's Space Telescope Science Institute, followed by work at the University of Melbourne and Columbia University. He's now a professor at the City University of New York's Lehman College and an Associate at the American Museum of Natural History's Hayden Planetarium.
Previous host Gabe Perez-Giz is an astrophysicist who studies black hole physics. He received his Ph.D. from Columbia University and also hosted PBS Infinite Series.


15:25How Decoherence Splits The Quantum Multiverse
How Decoherence Splits The Quantum MultiverseԴիտումներ 23հզր4 օր առաջ
17:17Does Consciousness Influence Quantum Mechanics?
Does Consciousness Influence Quantum Mechanics?Դիտումներ 390հզր8 օր առաջ
17:01Are Axions Dark Matter?
Are Axions Dark Matter?Դիտումներ 391հզր14 օր առաջ
16:56Are there Infinite Versions of You?
Are there Infinite Versions of You?Դիտումներ 315հզր22 օր առաջ
16:53Hacking the Nature of Reality
Hacking the Nature of RealityԴիտումներ 437հզր28 օր առաջ
16:17Solving the Three Body Problem
Solving the Three Body ProblemԴիտումներ 412հզրԱմիս առաջ
14:57How To Capture Black Holes
How To Capture Black HolesԴիտումներ 329հզրԱմիս առաջ
10:06How To Capture Ghost Particles ft. Don Lincoln
How To Capture Ghost Particles ft. Don LincolnԴիտումներ 251հզր2 ամիս առաջ
18:30Do Black Holes Create New Universes?
Do Black Holes Create New Universes?Դիտումներ 735հզր2 ամիս առաջ
17:50The Doomsday Argument
The Doomsday ArgumentԴիտումներ 455հզր2 ամիս առաջ
16:39Is The Universe Finite?
Is The Universe Finite?Դիտումներ 698հզր2 ամիս առաջ
18:29Can You Observe a Typical Universe?
Can You Observe a Typical Universe?Դիտումներ 416հզր3 ամիս առաջ
17:24Does Life Need a Multiverse to Exist?
Does Life Need a Multiverse to Exist?Դիտումներ 565հզր3 ամիս առաջ
15:59Why We Might Be Alone in the Universe
Why We Might Be Alone in the UniverseԴիտումներ 812հզր3 ամիս առաջ
13:01Is Time Travel Impossible?
Is Time Travel Impossible?Դիտումներ 578հզր4 ամիս առաջ
17:33Loop Quantum Gravity Explained
Loop Quantum Gravity ExplainedԴիտումներ 520հզր4 ամիս առաջ
14:19Black Hole Harmonics
Black Hole HarmonicsԴիտումներ 415հզր4 ամիս առաջ
18:45How Many Universes Are There?
How Many Universes Are There?Դիտումներ 599հզր5 ամիս առաջ
18:17Is Pluto a Planet?
Is Pluto a Planet?Դիտումներ 465հզր5 ամիս առաջ
19:37Could We Terraform Mars?
Could We Terraform Mars?Դիտումներ 889հզր5 ամիս առաջ
14:13Is Earth's Magnetic Field Reversing?
Is Earth's Magnetic Field Reversing?Դիտումներ 727հզր5 ամիս առաջ
12:59How To Become an Astrophysicist + Challenge Question!
How To Become an Astrophysicist + Challenge Question!Դիտումներ 177հզր6 ամիս առաջ
13:51What Happened Before the Big Bang?
What Happened Before the Big Bang?Դիտումներ 838հզր6 ամիս առաջ
5:31Exploring a HUGE Radio Telescope in VR 180
Exploring a HUGE Radio Telescope in VR 180Դիտումներ 282հզր7 ամիս առաջ
13:28What Caused the Big Bang?
What Caused the Big Bang?Դիտումներ 699հզր6 ամիս առաջ
10:12Deciphering The Vast Scale of the Universe | STELLAR
Deciphering The Vast Scale of the Universe | STELLARԴիտումներ 804հզր7 ամիս առաջ
13:34Did Time Start at the Big Bang?
Did Time Start at the Big Bang?Դիտումներ 1.3մլն7 ամիս առաջ
15:20The Quantum Internet
The Quantum InternetԴիտումներ 466հզր7 ամիս առաջ
18:42Thorium and the Future of Nuclear Energy
Thorium and the Future of Nuclear EnergyԴիտումներ 1մլն8 ամիս առաջ
8:33The Quasar from The Beginning of Time | STELLAR
The Quasar from The Beginning of Time | STELLARԴիտումներ 545հզր8 ամիս առաջ
14:33How Black Holes Kill Galaxies
How Black Holes Kill GalaxiesԴիտումներ 747հզր8 ամիս առաջ
15:41The Alchemy of Neutron Star Collisions
The Alchemy of Neutron Star CollisionsԴիտումներ 598հզր8 ամիս առաջ
15:21The Cosmic Dark Ages
The Cosmic Dark AgesԴիտումներ 514հզր9 ամիս առաջ
17:15Why Quantum Computing Requires Quantum Cryptography
Why Quantum Computing Requires Quantum CryptographyԴիտումներ 312հզր9 ամիս առաջ
12:07The Real Science of the EHT Black Hole
The Real Science of the EHT Black HoleԴիտումներ 437հզր9 ամիս առաջ
14:38No Dark Matter = Proof of Dark Matter?
No Dark Matter = Proof of Dark Matter?Դիտումներ 575հզր10 ամիս առաջ
18:24The Holographic Universe Explained
The Holographic Universe ExplainedԴիտումներ 1.2մլն10 ամիս առաջ
18:30The Edge of an Infinite Universe
The Edge of an Infinite UniverseԴիտումներ 2մլն10 ամիս առաջ
15:49Could the Universe End by Tearing Apart Every Atom?
Could the Universe End by Tearing Apart Every Atom?Դիտումներ 625հզր11 ամիս առաջ
18:22Is Dark Energy Getting Stronger?
Is Dark Energy Getting Stronger?Դիտումներ 543հզր11 ամիս առաջ
16:23Will You Travel to Space?
Will You Travel to Space?Դիտումներ 216հզր11 ամիս առաջ
16:31The Impossibility of Perpetual Motion Machines
The Impossibility of Perpetual Motion MachinesԴիտումներ 1.4մլն11 ամիս առաջ
17:11Secrets of the Cosmic Microwave Background
Secrets of the Cosmic Microwave BackgroundԴիտումներ 420հզրՏարի առաջ
17:32Sound Waves from the Beginning of Time
Sound Waves from the Beginning of TimeԴիտումներ 438հզրՏարի առաջ
15:15Perpetual Motion From Negative Mass?
Perpetual Motion From Negative Mass?Դիտումներ 484հզրՏարի առաջ
18:05The Crisis in Cosmology
The Crisis in CosmologyԴիտումներ 738հզրՏարի առաջ
18:27Our Antimatter, Mirrored, Time-Reversed Universe
Our Antimatter, Mirrored, Time-Reversed UniverseԴիտումներ 458հզրՏարի առաջ
13:54Are Dark Matter And Dark Energy The Same?
Are Dark Matter And Dark Energy The Same?Դիտումներ 418հզրՏարի առաջ
18:39Why String Theory is Wrong
Why String Theory is WrongԴիտումներ 1.2մլնՏարի առաջ
17:11Quantum Physics in a Mirror Universe
Quantum Physics in a Mirror UniverseԴիտումներ 400հզրՏարի առաջ
18:34Did Life on Earth Come from Space?
Did Life on Earth Come from Space?Դիտումներ 478հզրՏարի առաջ
17:32'Oumuamua Is Not Aliens
'Oumuamua Is Not AliensԴիտումներ 638հզրՏարի առաջ
16:26Supersymmetric Particle Found?
Supersymmetric Particle Found?Դիտումներ 726հզրՏարի առաջ
16:48Why String Theory is Right
Why String Theory is RightԴիտումներ 1.1մլնՏարի առաջ
17:14Are Virtual Particles A New Layer of Reality?
Are Virtual Particles A New Layer of Reality?Դիտումներ 543հզրՏարի առաջ
17:37Will We Ever Find Alien Life?
Will We Ever Find Alien Life?Դիտումներ 918հզրՏարի առաջ
16:38What are the Strings in String Theory?
What are the Strings in String Theory?Դիտումներ 1մլնՏարի առաջ
15:09Computing a Universe Simulation
Computing a Universe SimulationԴիտումներ 431հզրՏարի առաջ
15:48How to Detect Extra Dimensions | Space Time
How to Detect Extra Dimensions | Space TimeԴիտումներ 881հզրՏարի առաջ
16:41Quantum Gravity and the Hardest Problem in Physics | Space Time
Quantum Gravity and the Hardest Problem in Physics | Space TimeԴիտումներ 1.2մլնՏարի առաջ
16:12How Much Information is in the Universe? | Space Time
How Much Information is in the Universe? | Space TimeԴիտումներ 485հզրՏարի առաջ
12:25The Black Hole Entropy Enigma | Space Time
The Black Hole Entropy Enigma | Space TimeԴիտումներ 510հզրՏարի առաջ
13:42Is There Life on Mars? | Space Time
Is There Life on Mars? | Space TimeԴիտումներ 300հզրՏարի առաջ
17:53How Will the Universe End? | Space Time
How Will the Universe End? | Space TimeԴիտումներ 1.5մլնՏարի առաջ
16:30Quantum Theory's Most Incredible Prediction | Space Time
Quantum Theory's Most Incredible Prediction | Space TimeԴիտումներ 1.2մլնՏարի առաջ
14:15How Close To The Sun Can Humanity Get? | Space Time
How Close To The Sun Can Humanity Get? | Space TimeԴիտումներ 386հզրՏարի առաջ
14:01Reversing Entropy with Maxwell's Demon
Reversing Entropy with Maxwell's DemonԴիտումներ 463հզրՏարի առաջ
12:20The Misunderstood Nature of Entropy
The Misunderstood Nature of EntropyԴիտումներ 698հզրՏարի առաջ
13:04Quantum Invariance & The Origin of The Standard Model
Quantum Invariance & The Origin of The Standard ModelԴիտումներ 362հզրՏարի առաջ
13:49Will A New Neutrino Change The Standard Model?
Will A New Neutrino Change The Standard Model?Դիտումներ 348հզրՏարի առաջ
11:58How Asteroid Mining Will Save Earth
How Asteroid Mining Will Save EarthԴիտումներ 417հզրՏարի առաջ
15:30The Black Hole Information Paradox
The Black Hole Information ParadoxԴիտումներ 603հզրՏարի առաջ
14:08What Survives Inside A Black Hole?
What Survives Inside A Black Hole?Դիտումներ 688հզրՏարի առաջ
13:43Why Quantum Information is Never Destroyed
Why Quantum Information is Never DestroyedԴիտումներ 500հզրՏարի առաջ
13:02Noether's Theorem and The Symmetries of Reality
Noether's Theorem and The Symmetries of RealityԴիտումներ 519հզրՏարի առաջ
10:45How Gaia Changed Astronomy Forever | Space Time
How Gaia Changed Astronomy Forever | Space TimeԴիտումներ 351հզրՏարի առաջ
11:04The Star at the End of Time | Space Time
The Star at the End of Time | Space TimeԴիտումներ 981հզրՏարի առաջ
11:32Black Hole Swarms | Space Time
Black Hole Swarms | Space TimeԴիտումներ 798հզրՏարի առաջ
12:47Using Stars to See Gravitational Waves
Using Stars to See Gravitational WavesԴիտումներ 232հզրՏարի առաջ
13:41The Physics of Life (ft. It's Okay to be Smart & PBS Eons!) | Space Time
11:14The Unruh Effect | Space Time
The Unruh Effect | Space TimeԴիտումներ 729հզրՏարի առաջ
12:02The Andromeda-Milky Way Collision | Space Time
The Andromeda-Milky Way Collision | Space TimeԴիտումներ 1մլնՏարի առաջ
9:28Scientists Have Detected the First Stars | Space Time
Scientists Have Detected the First Stars | Space TimeԴիտումներ 565հզրՏարի առաջ
12:06Hawking Radiation
Hawking RadiationԴիտումներ 744հզրՏարի առաջ
12:40Should Space be Privatized? | Space Time
Should Space be Privatized? | Space TimeԴիտումներ 184հզր2 տարի առաջ
8:48The Trebuchet Challenge | Space Time
The Trebuchet Challenge | Space TimeԴիտումներ 178հզր2 տարի առաջ
12:01The Death of the Sun | Space Time
The Death of the Sun | Space TimeԴիտումներ 295հզր2 տարի առաջ
14:19What is Energy? | Space Time
What is Energy? | Space TimeԴիտումներ 907հզր2 տարի առաջ
9:47Kronos: Devourer Of Worlds | Space Time
Kronos: Devourer Of Worlds | Space TimeԴիտումներ 569հզր2 տարի առաջ
14:15The End of the Habitable Zone | Space Time
The End of the Habitable Zone | Space TimeԴիտումներ 844հզր2 տարի առաջ
14:56Horizon Radiation | Space Time
Horizon Radiation | Space TimeԴիտումներ 338հզր2 տարի առաջ
13:50What Do Stars Sound Like? | Space Time
What Do Stars Sound Like? | Space TimeԴիտումներ 290հզր2 տարի առաջ
1:36Space Time VR
Space Time VRԴիտումներ 97հզր2 տարի առաջ
13:09Extinction by Gamma-Ray Burst | Space Time
Extinction by Gamma-Ray Burst | Space TimeԴիտումներ 563հզր2 տարի առաջ
11:36The Origin of 'Oumuamua, Our First Interstellar Visitor | Space Time
The Origin of 'Oumuamua, Our First Interstellar Visitor | Space TimeԴիտումներ 1.3մլն2 տարի առաջ
10:33Citizen Science + Zero-Point Challenge Answer | Space Time
Citizen Science + Zero-Point Challenge Answer | Space TimeԴիտումներ 137հզր2 տարի առաջ
16:48Suicide Space Robots | Space Time
Suicide Space Robots | Space TimeԴիտումներ 246հզր2 տարի առաջ
10:09Zero-Point Energy Demystified | Space Time
Zero-Point Energy Demystified | Space TimeԴիտումներ 744հզր2 տարի առաջ
11:36The Vacuum Catastrophe
The Vacuum CatastropheԴիտումներ 836հզր2 տարի առաջ
13:23The Missing Mass Mystery | Space Time
The Missing Mass Mystery | Space TimeԴիտումներ 705հզր2 տարի առաջ


  • If you flip a penny, what are the chances it will come up cat?

  • anyone thought what will he look like if he go bald? 😂 (Just fun)

  • If from my perceptive of history it does not matter which story of history is true then does than mean both histories are true. Would this count as a macroscopic example?

  • I can only guess the future dictactes the past. See what I did there? Did I say it right? I can't say... might be jibberish...

  • at long last you have articulated what i have believed for years. Observation does not occur, only further entanglement.

  • why does the man with an eye as a head wear glasses instead of a monocle?

  • Are the different "histories" physical realities? Would that cause an infinite amount of energy , assuming that the generation of different realities requires/generates energy?

  • what a waste of time consciousness not needed its the collision needed for positional certainty which causes the collapse certainty kills probability you heard it here!

  • nice! Was waiting for a decoherence video ever since the quantum eraser destroyed my world views

  • I scared myself... I actually did get it. For one of the first times. The double, double slit experiment is what made it click. If the waves converge further down the optical path however offset they may be, the coherence is preserved, if one diverges and never makes it through the second slit, (i.e.never reunites with the other photon), coherence is lost forever. I think... :) And when you attempt to measure the photon, you introduce "noise" that blurs all trace of the original phase, causing decoherence.

  • This definitely explains the measurement problem for the many worlds interpretation for me.

  • This whole ordeal makes me doubt the photons coming from my monitor.

  • I wonder why no quantum Mambo jambo scifi movie hasnt come up with decoherence dampeners yet...

  • It makes a lot of sense and it's gonna piss a lot of people off because of it too.

  • I love the way you use the melody from thgttg tetriary phase and beyond. hahaah gj!

  • Now you're just making stuff up.

  • Awareness is meaurement. It's all simulations. 0 = base awareness/measurement 0 is not a placeholder. It's the base point of measuring probabilities for AI. We are all AI in an existence were the magic of consciousness is equal too the vastness of mathematics.

  • Gravity is the mass around the nutrition for all starry hosts - planets and moons. Neutrino gets open only by a neutron star 🌟 that is the peak point of black hole 🕳

  • Do we really need Everett's many worlds interpretation for a solution to the measurement problem? I thought Bohemian mechanics together with decoherence solves it without the need for an infinite number of universes.

  • There's no reason to reject the possibility that our history does diverge and combine during our activities. Let's say there's a bazillion worlds. Why wouldn't they combine and diverge? Of course you're more interested in forcing or witnessing it. I like many world's. You can't measure and compute anything on the macro scale and probably never will be able to. But if everyone tries to measure the same pure silicone mm3 block maybe we'll experience some kind of combined timelines. Lol. But we won't be able to tell for sure.

  • so whenever ur 8th grade physics teacher says "observation", raise your hand and say... "maam, it would be more accurate to say interaction"

  • Does this idea of decoherence conflict with the "spooky action at a distance" of entangled particles in that it's saying there's a hidden variable of the wave function or complex of wave functions at work that we only discover when we measure the properties of one particle or another?

  • One thing that's always bothered me about the idea of wave function collapse is that there's nothing in existence with a definite point position to experience that collapse, there are only particles with associated wave functions that absorb it into their wave functions. I think it leads to a more intuitive picture to think about the probability aspect not as the path of the particle but rather as which particle interacts with its wave function, forcing a quantized change that prevents any other particles from doing so.

  • What about the quantum eraser? We measured but destroyed the information afterward. The interference pattern remained on the screen even though the coherence was lost by measuring which slit the particle went through in the first place.

  • Is Schroedinger's cat coherent?

  • i sometimes ask myself if he lowers his voice intentional, like the theranos girl did to sound more autorative ,,, i like this channel but you might be a sociopath my friend , btw ever heard of Chan Thomas and how the earth will end in 2046 , every 12065 years sun goes nova and sheds outer layers , they found glass in desert so they did mission to moon and they found glass there ,,, suspicious observers is a good channel for info

  • Noticing the video after 4 hours gained me 10^56th place in the comments

  • My brain just collapsed

  • We focused on a simple question: does conscious observation of a quantum system cause wave function to collapse. Lol

  • what

  • Now explain the quantum earaser experiment using this knowledge

  • I think "multiple universes" is loaded and imho wrong therm. Decoherence is natural part of waves. If everything is made up out of waves like QT predicts then it is natural that only coherent waves will interact with each other. Decoherence also doesn't mean creating stuff out of nothing. Decoherence is just wave spreading out like in pond creating complicated scenarios. Just that one wave on pond creates infinite amount of complexity despite not producing any new universe and if you have 2 waves, 3, 5 or more you can get such place that they will all cancel each other out and you will think there are no waves and vice versa. Somehow when you are on peak of wave you don't believe that rest of waves don't exist and yet here we are.

  • I tried using the title to woo a girl I fancied. I 'll never make that mistake again. In all and every universe.

  • What about quantum incoherence :) maybe it’s just using probabilities and we can’t probe that deeply and know anything with any certainty

  • We are all one, friends!

  • Thank you. Now I understand. Decoherence, not to be confused with interference, wave function collapse or quantum entanglement...

  • Not if the wave is always there and photons electrons just ride it...

  • Someone has to be first and its us. Age of universe, age of Earth, two sun cycles, only enough time for one emergent inteligence? One day we will be called the Ancients! Unless we destroy ourselves.

  • There’s coherence, decoherence, and then there’s incoherence. Have to watch this a few more times.

  • I feel like physics is adopting explanations - decoherence, etc. to avoid accepting a 4D reality where time and space are the same thing. Matter and energy have oscillations in all 4 dimensions. We observe (our brains interpret) only the 3D part that corresponds to our current 4D displacement. We only observe what appears to be forward direction in time. We currently only look to the current or past with our calculations. We need to include the future as influential on current events. A new twist on thinking.

  • I don’t know what you said but I just understood something. That’s why I watch this show all the time. Thanks

  • Is there any chance that the measurement itself puts the particle in the 0% chance position? If so, can the measurement break somehow the Heisenberg principle?

  • Sean Carrol will be very happy to see this episode! Does decoherence work the same in Bohmian mechanics?

  • I don't know about decoherence, but I know I'm frequently incoherent.

  • How does this explain the delayed choice and quantum eraser?

  • I thought decoherence and wavefunction collapse was the same thing.

  • Is this the many-worlds interpretation of quantum theory? Sean Carroll has great lectures on this which seem to correlate with the principles you have outlined here. Well, I finished your video and you just mentioned it :) nice!

  • When did they start posting the channel in Klingon, as translated by Google Translate through Latin turned into binary translated back into English with Duolingo?

  • Is this guy speaking English?

  • A particle only comes about when the field energy density is high enough. The wave function might actually determine the strength of the field at any given point at any given time. Only when the field energy is high enough at some point in time and space can the energy in a specific location in the field BEHAVE like a particle due to influence from the forces which may in turn manifest due to proximity to other particles. Does coherence mean that all the energy the wave function contains goes into the particle? I think not. The rest of the wave function could still be guiding some of the energy along all possible histories. But not enough to manifest a quantum particle. Or at least I think such might be the case. A stable orbital can contain enough energy for two electrons. Maybe even 2.9999... electrons. Maybe the probability wave the wave function describes is the same. 1.9999? Probably. 3.9999.... / n.9999? Who knows?

  • try saliva .. youll see it fallowing the directions helps to have a spotter... luv the N.A.P. ..

  • If we die we will see all the other slices

  • One thing that does not add up for me is if it is the measurement device interacting with the particle that causes the wave to collapse, then how do we still get a n interference pattern if we take the measurement, but destroy the result? How would that also explain the delayed choice quantum eraser? Neither of those should be possible if it was the measurement device interacting with the particle that causes the collapse. It has to be the fact that the result is knowable, not that the measurement was taken. Right?

  • What?

  • Please, take this and re-visit the delayed choice quantum erasure and Bell's theorem.

  • Heres an interesting question that hasnt been addressed (@0:51) : is there such thing as observation without consciousness?

  • Must it be infinitely far away? What if we are actually the surface itself?

  • It's like, is light (energy?) even a real part of the universe? Like it can't be created or destroyed, unlike everything that we can interact with (or matter I guess). Like does it come from somewhere else; just passing through?

  • That South Park you though...lmao

  • Matt, you should write a Star Trek episode.

  • You are totally ignoring the delayed choice quantum eraser. Care to explain?

  • Of course not. Entropy would need to be reversed if you go back in time. Space would need to shrink back and how would you do that? That would cost lots of energy and how would you get the universe to do so?

  • I still have a problem with the double slit experiment. I worry that the 3 dimensional slits are effecting the wave function. What if we used 2 dimensional slits in the experiment instead of 3D slits? My spatial awareness tells me that the results wont look the same. If what I say is true then idk what this means for physics.

  • And why u so thin?

  • We all know the moon is just a lump of cheese!

  • 9:20 I just had a thought. In SR, spacelike events, or events that aren't causally related, can be in any order depending on which frame of reference you're in. I see something similar here. When we're not observing the wave, it's a spacelike event and so it doesn't matter which slit the photon went through, possibly even both. But when we try to observe the wave, we establish causality, and it now becomes a timelike event and so the photon can't go through both slits at once.

  • I feel trapped now. :-(

  • That is SUCH a good explanation. Truly you have made this VERY understandable. I'd say your explanation is even better than anything I've heard from Sean Caroll (and that's saying a lot)

  • Title made my head bone hurt.

  • Hey at 9 seconds he says a word that sounded like gibberish but I'm sure it wasn't. How do you spell it? I'd like to google it.

  • sounds good.. i mean the notion of consciousness collapsing waves leads to biocentrism, there is no alternative then..then again, that might be just one interpretation of the decoherence, the biological in this case...well, a lot of infinities, thats for sure. How about superclose parallel universes then..? The dfference of some tree lets say..Are u sure we always stay in the same reality..? How so? Couldnt it be feedback effects within the general wavefunction that require local adaption? It also sheds a light on the meaninglessness of spacetime regarding entanglement effects, though im really not sure in which way..

  • How can you not be crazy after this video

  • Mmmm I don't feel comfortable with this explanation

  • 😂

  • So when you die, your wave function suddenly becomes coherent again becuz you lost your observation skills and you start existing everywhere, everytime... and when you are born, you are just a collapsed wave function. Imma go die now, thanks (jk)

  • What's the difference between an observation and an event that isn't observed?

  • My head hurts. And I did all this at uni in 1973!

  • This is by far the best "intuitive" explanation of quantum decoherence (and of the many worlds interpretation) I've seen so far. Thank you, amazing work!

  • Is quantum coherence a binary property (coherent/non-coherent) or can something be partially coherent? Is coherence reason why interference pattern is blurred? Also could you further explain concept of quantum history?

  • Ever since I found out that decoherence can explain apparent wavefunction collapse, but is already predicted by QM without the assumption of wavefunction collapse, I have been confused as to why wavefunction collapse is still the most popular interpretation. Why posit wavefunction collapse if it isn't needed to explain anything? There is no evidence for wavefunction collapse, so all it does is make the theory less parsimonious.

  • Every time I see the double slit experiment I ask myself: What happens if one of the Slits has different forms or surfaces?

  • So consciousness could be the subjective perception of only a slice of reality. I suppose the trick, then, is to always be surfing down a desirable branch.

  • Finally a quantum interpretation free of the magical thinking of an observer.

  • Much food for thought. Interesting. Thank you for sharing!

  • Is there a possibility that the double slit experiment is flawed? For example, has it been conducted in a vacuum or only air? Is there a possibility the air molecules interacted with the electrons, causing the interference pattern? Also can a different particle be used? Say, a neutron? Or a proton, if you need a charged particle? Perhaps a positron for something equal in mass to the electron? Or maybe a neutral particle with the same mass and size as an electron. I’m no scientists, just a curious idiot.

  • I think it goes with out saying that the great philosophers of yesteryear would have said "Screw it," if quantum mechanics was a thing hundreds of years ago.

  • You can split my black hole with your quantum mechanics any day

  • Finally! Measurement and wave function collapse does not seem to be "magical"! Now I want to see that decoherence in action on walking oil droplets systems (pilot wave interpretation analog) by putting some "detector" near one of the slits.

  • Alice, a.k.a human Angel's fell through the black hole and landed in a fake holographic universe. Chershire Cat's out of the bag.😁

  • I think this is the nature of all reality. There is only one fundamental function that everything else repeats on and recombined from. In my hypothesis it is an issue of the struggle between non-existence and existence, giving rise through time and space folding and chaotic recombination which gives form to everything else. Everything is the same thing, down to the most basic fabric of all reality.

    • It also creates a kind of strange notion of reincarnation. Like you mentioned, where everyone is a reflection of everyone else. The annoying thing here is of course that it is non-falsifiable. Not a great candidate for empiricism. But the quantum universe doesn’t have to obey what we want it to be.

  • OMG, your beard is now salty!

  • Wouldn’t all of those alternate histories continuing to exist next to each other, such that there are actually many worlds, result in weird infinite interactions via gravity? Assuming gravity isn’t quantum? Like, the collapse of the wave function, in this description, sounds like the electron is cloned and we’re only able to observe the one clone. But the other one is still out there, having mass in the universe.

  • If there are multiple universes, are there 2 that are identical? infinite identical galaxies for each of the infinite possibilites?? rough.

  • This was probably the best video on decoherence I have seen. The way you explained it I picked up aspects of entropy and information theory! Can't wait for the next few videos

  • so decoherence==heat?

  • Can you talk about the Penrose's OOR

  • I think I "get" Everettian cosmology and it does seem like a very straightforward solution to this problem but at a purely subjective, human-being sort of level it's difficult to accept. I'd vaguely expect there to be some kind of corollary to it that says that the splitting realities in some sense do average out and that all of the splits that occur at every quantum event somehow still amount to the same reality as long as the results of the split are not macroscopically significant, or something like that.

  • Sabine Hossenfelder says in one of her videos that Many-worlds does not solve the measurement problem but I did not follow her argument. It would be good if you could take a shot at explaining that point here

  • How does the Quantum Eraser experiment fit into this, does it re-establish coherence retrospectively?

  • When you stop this video sometimes he looks like he is coming to eat your brain !