Hey Space Timers! A few of you caught an little error on our part in the merch shoutout. And you are all technically correct, the best kind of correct! The Higgs UV shirt & hoodie will be available for sale at the Merch Store until July 4th, but we are currently past the date where we can guarantee delivery by July 4th. (shipping usually takes about two weeks). Hope that clears things up!
how do you feel about this argument through the lens of the planck length? does that have any bearing on the frame of reference argument as you see it?
I always thought of spin as "that meaningless quantum number". Meanwhile, Matt casually explains what it is, its origins, and the implications of it having other values. I don't think a lot of people can fully appreciate what happened here. Incredible work, hats off!
I did my degree in Physics and Math, and can genuinely say that I've gained more understanding from PBS Space Time than I did in all that degree. Just goes to show the value in teaching to the subject rather than training for an exam.
@@Selieca Does this mean you crammed the matter and did an exam, without ever being tutored, or that you had a shitty math professor? And you passed, so it must have not been that bad.
I used to build ESR (Electron Spin Resonance) AKA ESR (Electro-Parametric Resonance) Spectrometers, and the latter is the more modern designation. Spin's just a word that sounded right at the time they needed a name, and was already iffy back then too.
Well it's either a minute ..or hours of qft, determining anti-commutation relations work for Dirac field, seeing this yields an anti-symmetrical wave-function and concluding the exclusion principle. As bonus after hours more, through spin-statistics theorem interestingly also largely due to Pauli getting the Fermi-Dirac distribution that maxes at 1 occupancy per state you further see it also statistically It's really no in between: either a postulate or developing rather complicated objects that are needed to properly describe the simplest fermionic particles in our space-time
Careful summoning them from dimension 0. 4D spacetime doesn’t like having a consciousness both infinite and pure oblivion existing in our finite reality
Thank you SpaceTime for doing your part to educate the masses, but also putting your sponors at the end of the video. It tells me how much you respect your audience.
I watched the whole video just to understand this, and the end I get but not the maths along the way. And it's so cool that I wonder... Could there have been any time at the beginning of the universe, or are there other regions, where potential anyions do mostly or entirely move only within a 2d plane?
@@Kuiriel look up self pumping phase-conjugated mirrors. If you didn't catch that at the end he hinting to somthing. A particle of 1/3 spine is also called a Graviton... you can you phase-conjugated waves in a fractal tyroidal tripole moment to cause quantum teleportation of a macroscopic object. How would you like to teleportat a speed of 4c. Look up bob greenyer, salvitore paiz, John hutchison, Eric w. Davis. Mh370x Ashton forbes. You'll figure it out. I warn you now looking into this will make you question everything...if you are fixed hard to a belief system I would not look into this. 😂 you will lose it lol
Probably one of the best videos for me. Don’t know why but all of this made sense to me. Pretty sure all the years of watching Matt have finally started to sink in and click. Thank you.
18:10 this conflicts with the reasoning used to disprove "real" anyons. The reasoning was that even when the particles were constrained to a 2d plane, the embedding of that plane within a 3d space precludes anyons since the plane can be viewed from either side. And that describes the physics experiment too -- the particles are confined to a 2d plane, but that plane is embedded in 3d space and can be viewed from either side
Maybe the configuration of the magnetic fields used to manipulate the spins is indicating a preferential perspective, resolving the "which side" ambiguity...?
If I understood correctly it was the constraining of the particles to a 2D plane within a 3D configuration space which was used to prove the impossibility of anyons, not real space. The real space restriction to 2D plane means the configuration space doesn't need to be 3D and restricted, the configuration space is simply 2D.
@@MNbenMN In that case wouldn't any gradient or directional field in a 1D space, even if it doesn't interact with the particles at all, make anyons impossible, as left could be distinguished from right? Actually, the whole idea of not being able to put a 2D space into 3D, because you can look at it from different sides just isn't really making any sense to me.
This is one of the few episodes where it's very difficult to parse even with the incredible effort and diagrams. That said! I had an awesome ah-ha moment with the clockwise flip demonstrations indicating why it's only possible to have multiples of pi as spin due to the mathematics behind that transformation with 3 spatial dimensions. Will be pretty neat if this results in 'Anyonic Quantum Super Computers' in the future, even it's hard to even understand what that would even look/behave like!
I feel somewhat confident that there are some substantial errors in the diagrams shown. In the diagrams where two particles move in a 2D space on the left, and the right side is supposed to be showing the part of the configuration space other than the center of mass information, I don’t think the correspondence is as it should be. The two particles shouldn’t be passing through each-other. Rather, in order to make a loop on the image on the right, they should be going around in opposite directions such that they exchange positions without passing through each-other. It’s *possible* that what is shown does make sense, but is just shown in a way that is very different from how I would show it, and also not explained in a way that makes clear to me how the illustration is meant to work, but, I really think some of the people behind the show just misunderstood some things. So, you know how the anti-symmetry requires that the amplitude for two electrons having the same position, be zero, because that’s the only thing that is equal to its own negation? The same thing happens with anyons, except instead of “it’s own negation” it is “it multiplied by (some phase factor other than 1) “ It isn’t when the anyons pass through each-other that the system picks up a phase factor, as, they never pass through each-other. It is when they switch places without passing through each-other . (Well, if they did pass through each-other, that would probably also kinda pick up a phase... but that’s not the relevant scenario.) What they should have, is on that cone, the two passing through each-other should be going through the tip of that cone.
@@drdca8263 now obviously since I had a hard time parsing it I can't really speak on it's accuracy, but are you certain the information is incorrect and not merely skewed a bit due to the limitations of finding an approachable approximation of 6 dimensional space?
@@johnmichaelchase8530 I was talking about the “2 particles in 2D” part, where the full configuration space is only 4D (and only 2 of them relevant). The broad strokes of what he said was right, as were many of the details. Actually, maybe all the things he *said* were right? It’s possible that I’m wrong. But I’m at least 70% sure that there’s an error in those diagrams. I would have explained the “why not in 3D?” part slightly differently, but it was still good. (not to mention the error of writing “e^(i pi eta) = 0 when eta is even” (should be 1, not 0))
Fascinating! But I must say, really feels like you buried the lead here 😅 "There’s this special, 3rd(infinity-th?) type of particle, that only exists mathematically, and only in lower dimensional spaces... except we can artificially make materials which behave like their in lower dimensions, and suddenly this particle behaviour emerges!" That's UTTERLY WILD And I totally get that we won't understand until you've walked us through the math... but still, come on! That's SO COOL, let us know up-top that the difficult math is heading to somewhere so interesting! 😍
im afraid to even ask how scientist came to a thought that particles might start behaving like in 2d space just by barely constraining their movement in there, i mean they are still in 3d space so why they start to act differently?
@@Andrius319 in condensed matter physics there's actually plenty models - and experimental realisations - that describe 2 or even 1d behaviour! There are even various theoretical results that prohibit certain phenomena in lower dimensions, search for the Mermin-Wagner theorem. Some methods like the mean-field work better in higher dimension and so on
It's insane how such insane math underlies so much of our universe. This episode, more than any other, made me realize it really IS just maths all the way down. We are insane complex mathematical objects that somehow produce consciousness.
Sadly, Maths are also the reason science as gone so astray. To a bean counter, everything is a bean to be counted....even things that are not beans or countable. Many mathematicians out there have wasted their entire life on theories they can support with math that are pure fantasy, useless in predicting anything, and set back scientific advancement for a generation.
I remember reading about that experiment and not really understanding the significance of it at all. This video explains it brilliantly and now I also understand why there are bosons & fermions. Thanks!
man, I really lost you in the middle, but glad I stayed for the punchline! This sounds like the most genuine version of us hacking the universe through our mathematical knowledge I've heard yet!
Ever notice how often Limited Time ads are at least partially misscheduled? Vid: "To get this merch, you have to order by June 23rd." Vid airs on the 27th.
PBS Spacetime: "...that naming an electron is silly." Me: "Oh, not this again. Eric the 1/2 Electron is not going to be happy hearing them say this again."
don't trust me on this (I have no idea what I'm talking about) but I think no because the rules of the boundary would be completely different from the rules of the bulk
Yes. But in that specific case 2 "non-connected" events in either space or time should be able to influence each other if they were connected at some point. I never heard of something like that(~~quantum entanglement~~)
They recorded that merch ad already for the last video and probably didn't bother to re-record. They still wanted to have the ad in there and the information regarding the deadline is not wrong and also still relevant for people to know they won't receive it before July 4.
Wait wait. These researchers made anyons with spin _exactly_ 1/3, _roughly_ 1/3 or _indistinguishable_ from 1/3? These are algebraically very different.
@@damonedrington3453 By construction. I could do something with the inherent property that doing it three times comes back to the physically enforced integral 1 state, or I could do something approximate with sufficient precision that a test for 1/3 would pass. Something similar happens all the time in computing; rational 1/3 is just not the same as floating 1/3. In physics the rationals are apparently the same ones we use in maths and computing, but floats are replaced by distributions (which are different again from Reals, which are a special-surprisingly complicated-construction invented by mathematicians to make those two notions coincide). If that makes sense?
These are quotes from the 1990 paper "Theory of the fractional quantum Hall effect" abstract. _The main assertion is that new candidate incompressible states can be constructed by taking products of some known incompressible states, and all incompressible states can thus be generated starting from the states at integer filling factors._ _Numerical results show that these trial states very accurately describe the transition from the 1/3 state to the 2/5 state for a four-electron system._ _Even though the fractional quantum Hall effect is found to be possible at all rational filling factors in this approach, it is indicated why the odd-denominator fractions are in general more stable than the even-denominator ones._ It sounds like they're supposed to be exact fractions, just like regular particles. The part about stability kind of sounds like there can be minute deviations, but maybe an unstable anyon just disintegrates or breaks confinement or immediately transitions to a different (but exact) flavor.
@@halyoalex8942 To be even more specific, Matt said it in the video "Why Quantum Information is Never Destroyed" (ca. 4:33) and the text is even written on screen, so a screenshot of that became a meme. I don't think this is the first time Matt has called back to it since it became a meme, but I can't quite remember.
What happens if you keep going up the dimensions? What happens to this concept in a 4D universe? Or a 5D universe? Does it tell us if we can't have particular particles in higher dimensions?
You can always have anyon-like objects, but as you increase dimensions, you need to braid more complicated things to create them. In 2+1D (confined to a plane), you can braid particles. In 3+1D, you can braid rings. In higher dimensions, you braid higher dimension analogs.
Watch their standard model and standard model lagrangian playlists(in that order) and then watch whatever interests you. If you get through that, you'll catch on soon enough
the three-particle version of this can be neatly done on a sphere where you end up with eight copies of the space, one for each octant of the sphere. It's a useful tool for exploring the three body problem.
I thought the main reason I didn't fall through the floor was electromagnetic repulsion between electron shells, which I would think would have longer range than degeneracy pressure. Am I just confused?
you are right, but if electrons could exist in the same state, then they would all fall to the lowest energy and there would be no electron shells. So the electromagnetic repulsion is the direct reason, but it can only happen because electrons are fermions
Consider the fact that electrons within atoms are very tightly packed compared to interatomic distances.If repulsion were the only issue then you could fit around 100 hydrogen atoms inside one uranium atom while in reality only a few will fit. Charge is powerful; just look at how small of a magnet can fight the gravity of the Earth, but the near-neutrality of matter significantly dilutes it.
After the "kinks" in the last episode, I can't stop looking for these: 11:45 "It Pac Mans to the other side" Proceeds to draw a Pac Man. Matt should have worn his Game Over T-shirt.
Modern science really is the magic system of our universe. Hyper intelligent Mages are probing the deepest most esoteric facets of our reality, and then using special materials combined in very specific and ritualistic ways to exploit and manipulate said reality.
I Love PBS Space Time! I have watched every episode more than once. My mind still gets to thinking now I get it! But then time keeps ticking and things return back to normal. 😊 Keep it up, I'm still viewing!
*Summary* *The Standard Model:* * *(**0:11**)* The universe is made of fermions (matter, like protons and electrons) and bosons (force carriers, like photons and gluons). * *(**1:00**)* Fermions can't occupy the same quantum state, leading to quantum pressure. * *(**1:19**)* Bosons can occupy the same state. *Problems with the Traditional Explanation:* * *(**3:22**)* Saying fermions "swap places" is ambiguous due to quantum uncertainty. * *(**3:36**)* We can't truly label indistinguishable particles like electrons. *Introducing Anyons:* * *(**3:59**)* Anyons are a theoretical particle type, neither fermion nor boson. * *(**4:19**)* They arise from considering particle movement and interactions in 1D and 2D spaces. * *(**7:02**)* Anyons have unusual phase shifts when they "exchange" positions, unlike fermions or bosons. *Anyons in Different Dimensions:* * *(**10:15**)* Anyons are possible in 1D and 2D universes. * *(**13:05**)* In 3D (like ours), anyons are usually impossible because rotations would lead to contradictions in their behavior. *Creating Anyons in Our 3D World:* * *(**17:58**)* Scientists have created anyon-like behavior by trapping electrons between special materials and using magnetic fields. * *(**18:24**)* This allows for the study of their unique properties, such as fractional spin. *Potential Applications:* * *(**18:39**)* Anyons could revolutionize quantum computing by: * Allowing for more complex algorithms. * Enabling more stable storage of quantum information. *Conclusion:* * *(**19:11**)* Anyons expand our understanding of particles beyond the standard model. * While usually restricted to lower dimensions, we're learning to create and manipulate them in our 3D world, with potentially groundbreaking applications. i used gemini 1.5 pro to summarize the transcript
How can we create any-ons in our 3D universe, if the math show that it is not enough to simply restrain the 3D particles movement to a 2D plane. Won’t the mirrored observation effect still make them impossible in some “trapped in 2D” setup in a 3D universe?
Let's consider semiconductors. These are crystals in which an electron can absorb energy, leave its atom, and wander through the crystal This leaves an "electron-hole" where the electron was, and this hole also wanders through the crystal, and it behaves just like particle with positive charge Of course from outside the crystal we can see the hole is not a particle and we can describe its effects by talking about the electrons around the hole Anyons are similar, if we create them they behave as if they had different spin, but from outside this surface we can see that these are just electrons with spin 1/2, and we can describe everything that happens by just talking about electrons In a sense electron-holes and anyons are "illusions" but the effect they have is real Mesons are another kind of quasiparticle with the very real effect of keeping protons and neutrons together, and Cooper Pairs are quasiparticles that can transport electric current without resistance
This was one of my favorite episodes in a few episodes, because you gave us a sense of possibility. Can you do an episode on what it would take to unify or entangle humans with their environment, so that the function of one was transferred to the other in a superposition of states?
I've just finished a university quantum mechanics course and this video (around the 7 minute mark) finally made the e^(i*theta) phase factor click for me.
haven't gotten even a minute into the video but i had to comment...over the last couple videos, your voice has subtly changed, getting more "growly". i don't know if you are sick, and the videos are all shot close-together in time, but if not i highly recommend seeing a doctor to get fully checked out. voice changes are an early indicator of serious health problems related to the lungs and/or throat.
@@rogertoaster9385 lol, you are probably too young to know who he was, but peter jennings, a news anchor back when there were only a few channels, experienced similar voice changes before he was diagnosed with lung cancer. *always best to know.*
I must say that was amazing. I don't know if it was due to the help of my background in 3D computer science, but I almost understood everything this time. Thanks.
Impressive! We're making particles that can't exist in 3D space. As a complete amateur, i was wondering how thin that boundary line could be. The width of the wave length? Or infinitely thin.
1) Wouldn’t gravitons fit the description? 2) Maybe particles are distinguishable physically, but we lack the tools to discern the distinguishing features. Nice video!
Unobserved particles are in a future state. Because causality has a speed limit (c) every point in space where one observes it from will be the closest to the present moment. When one looks out into the universe they see the past which is made of particles (GR). When one tries to measure the position of a particle they are observing smaller distances and getting closer to the present moment (QM). The wave property of particles appears when we start trying to predict the future of that particle. A particle that has not had an interaction exists in a future state. It is a probability wave because the future is probabilistic. Wave function collapse is what we perceive as the present moment and is what divides the past from the future. GR is making measurements in the observed past and therefore, predictable. It can predict the future but only from information collected from the past. QM is attempting to make measurements of the unobserved future and therefore, unpredictable. Only once a particle interacts with the present moment does it become predictable. This is an observational interpretation of the mathematics we currently use based on the limited perspective we have with the experiments we choose to observe the universe with.
11:56: Particles are categorized as fermions or bosons based on their properties. 01:36: Fermions cannot occupy the same state due to quantum pressure effects. 02:17: Bosons can share states, allowing phenomena like lasers and light interference. 04:19: New particle type, anyons, emerges from rethinking particle indistinguishability. 06:01: Configuration space illustrates indistinguishable particles and their interactions. 08:01: Phase shifts occur in wavefunctions, affecting particle behavior upon reflection. 10:01: Anyons can have any spin, unlike fermions and bosons with fixed spins. 12:01: In 2D, anyons exist due to unique phase shifts during particle interactions. 17:11: In 3D, only bosons and fermions exist due to orientation constraints. 18:24: Anyons show potential in quantum computing, enhancing algorithm complexity.
Yessss, I am so biased, but I way prefer the particle physics to the astrophysics, and we just had that long series on black holes (Though admittedly that did involve quantum mechanics just as much) so it's good to be back!!
Damn. That felt like a geometry-based LSD trip, and I think it was beautiful. ❤ I always suspected Roger Penrose was your visual designer, got you! :D Brilliant deduction.
7:11 Error in reflecting photon diagram. It shows 0 phase change in the photon's wave after it reflects off the mirror surface. In the diagram, the photon hits at its wave's trough. For a pi phase shift, the exiting photon should start at its crest but is depicted as starting at its trough. I'm just commenting on this to help anyone else who might be confused like me. This diagram confused me when I tried to imagine the same animation of a photon being reflected at shallower angles (think: approaching 180°) and I noticed that the outgoing wave's phase would always incorrectly remain unchanged according to the original animation.
Mind blowing that we can make a two dimensional structure where anyons can exist, and that this could have practical applications in computation. It is almost like we are creating a lower dimensional universe with fantastic new particles.
Wow... this video was just at the limit of my understanding. But it was pretty mind-blowing to learn that researchers have been able to create theoretically impossible particles to potentially power a new type of quantum computer. That's really really cool!
Hey Space Timers! A few of you caught an little error on our part in the merch shoutout. And you are all technically correct, the best kind of correct! The Higgs UV shirt & hoodie will be available for sale at the Merch Store until July 4th, but we are currently past the date where we can guarantee delivery by July 4th. (shipping usually takes about two weeks). Hope that clears things up!
Correction 2: Don't listen to Matt, the 2 types of particle are turnmeons and bozos.
how do you feel about this argument through the lens of the planck length? does that have any bearing on the frame of reference argument as you see it?
Thanks for the Futurama reference! Keep up the good work!
Is this video sped up? Host is speaking faster than usual.
16:51, the RHS should be 1 and -1, not 0 and -1
I always thought of spin as "that meaningless quantum number". Meanwhile, Matt casually explains what it is, its origins, and the implications of it having other values.
I don't think a lot of people can fully appreciate what happened here.
Incredible work, hats off!
I did my degree in Physics and Math, and can genuinely say that I've gained more understanding from PBS Space Time than I did in all that degree. Just goes to show the value in teaching to the subject rather than training for an exam.
@@Selieca Excellent point!
I thought spin is what nbc and cnn does to make democrats look good, even though they are obviously evil af
@@Selieca Does this mean you crammed the matter and did an exam, without ever being tutored, or that you had a shitty math professor? And you passed, so it must have not been that bad.
I used to build ESR (Electron Spin Resonance) AKA ESR (Electro-Parametric Resonance) Spectrometers, and the latter is the more modern designation. Spin's just a word that sounded right at the time they needed a name, and was already iffy back then too.
Wait . . . what? You explained the Pauli exclusion principle in under a minute? This is what I have been looking for!
Well it's either a minute
..or hours of qft, determining anti-commutation relations work for Dirac field, seeing this yields an anti-symmetrical wave-function and concluding the exclusion principle.
As bonus after hours more, through spin-statistics theorem interestingly also largely due to Pauli getting the Fermi-Dirac distribution that maxes at 1 occupancy per state you further see it also statistically
It's really no in between: either a postulate or developing rather complicated objects that are needed to properly describe the simplest fermionic particles in our space-time
summoning entities from lower dimensions
again
Don’t do it with entities from higher dimensions!
@@volkhen0why not?
@@volkhen0 no room at the inn!
Witchcraft! 🙂
Careful summoning them from dimension 0. 4D spacetime doesn’t like having a consciousness both infinite and pure oblivion existing in our finite reality
Thank you SpaceTime for doing your part to educate the masses, but also putting your sponors at the end of the video. It tells me how much you respect your audience.
My man just spent 18 minutes explaining how these particles cannot exist and then just casually drops "anohyow, here's how to make them"
?
I watched the whole video just to understand this, and the end I get but not the maths along the way. And it's so cool that I wonder... Could there have been any time at the beginning of the universe, or are there other regions, where potential anyions do mostly or entirely move only within a 2d plane?
@@Kuiriel look up self pumping phase-conjugated mirrors. If you didn't catch that at the end he hinting to somthing. A particle of 1/3 spine is also called a Graviton... you can you phase-conjugated waves in a fractal tyroidal tripole moment to cause quantum teleportation of a macroscopic object. How would you like to teleportat a speed of 4c. Look up bob greenyer, salvitore paiz, John hutchison, Eric w. Davis. Mh370x Ashton forbes. You'll figure it out. I warn you now looking into this will make you question everything...if you are fixed hard to a belief system I would not look into this. 😂 you will lose it lol
@@flybennuhow
And how on the event horizon of a blackhole?
Very cool how a more rigorous explains why only two types are observed.
"Ok, class... Who can tell me what an η = X particle is called?
Anyone?
Anyone?
Anyone....?"
Bueller?
Anyone!
This really is a fantastic joke.
♾️
@@scotthammond3230 - Not Bueller, but Euler
Probably one of the best videos for me. Don’t know why but all of this made sense to me. Pretty sure all the years of watching Matt have finally started to sink in and click. Thank you.
18:10 this conflicts with the reasoning used to disprove "real" anyons. The reasoning was that even when the particles were constrained to a 2d plane, the embedding of that plane within a 3d space precludes anyons since the plane can be viewed from either side. And that describes the physics experiment too -- the particles are confined to a 2d plane, but that plane is embedded in 3d space and can be viewed from either side
Whatever these physicist are smoking, I want it too.
This
Maybe the configuration of the magnetic fields used to manipulate the spins is indicating a preferential perspective, resolving the "which side" ambiguity...?
If I understood correctly it was the constraining of the particles to a 2D plane within a 3D configuration space which was used to prove the impossibility of anyons, not real space. The real space restriction to 2D plane means the configuration space doesn't need to be 3D and restricted, the configuration space is simply 2D.
@@MNbenMN In that case wouldn't any gradient or directional field in a 1D space, even if it doesn't interact with the particles at all, make anyons impossible, as left could be distinguished from right?
Actually, the whole idea of not being able to put a 2D space into 3D, because you can look at it from different sides just isn't really making any sense to me.
This is one of the few episodes where it's very difficult to parse even with the incredible effort and diagrams. That said! I had an awesome ah-ha moment with the clockwise flip demonstrations indicating why it's only possible to have multiples of pi as spin due to the mathematics behind that transformation with 3 spatial dimensions.
Will be pretty neat if this results in 'Anyonic Quantum Super Computers' in the future, even it's hard to even understand what that would even look/behave like!
Very well stated! 👏🏼
I feel somewhat confident that there are some substantial errors in the diagrams shown.
In the diagrams where two particles move in a 2D space on the left, and the right side is supposed to be showing the part of the configuration space other than the center of mass information,
I don’t think the correspondence is as it should be.
The two particles shouldn’t be passing through each-other. Rather, in order to make a loop on the image on the right, they should be going around in opposite directions such that they exchange positions without passing through each-other.
It’s *possible* that what is shown does make sense, but is just shown in a way that is very different from how I would show it, and also not explained in a way that makes clear to me how the illustration is meant to work,
but, I really think some of the people behind the show just misunderstood some things.
So, you know how the anti-symmetry requires that the amplitude for two electrons having the same position, be zero, because that’s the only thing that is equal to its own negation?
The same thing happens with anyons, except instead of “it’s own negation” it is “it multiplied by (some phase factor other than 1) “
It isn’t when the anyons pass through each-other that the system picks up a phase factor, as, they never pass through each-other.
It is when they switch places without passing through each-other .
(Well, if they did pass through each-other, that would probably also kinda pick up a phase... but that’s not the relevant scenario.)
What they should have, is on that cone, the two passing through each-other should be going through the tip of that cone.
@@drdca8263 now obviously since I had a hard time parsing it I can't really speak on it's accuracy, but are you certain the information is incorrect and not merely skewed a bit due to the limitations of finding an approachable approximation of 6 dimensional space?
@@johnmichaelchase8530 I was talking about the “2 particles in 2D” part, where the full configuration space is only 4D (and only 2 of them relevant).
The broad strokes of what he said was right, as were many of the details. Actually, maybe all the things he *said* were right?
It’s possible that I’m wrong.
But I’m at least 70% sure that there’s an error in those diagrams.
I would have explained the “why not in 3D?” part slightly differently, but it was still good.
(not to mention the error of writing “e^(i pi eta) = 0 when eta is even” (should be 1, not 0))
I applaud Spacetime for communicating these complex interactions so well.
Fascinating!
But I must say, really feels like you buried the lead here 😅
"There’s this special, 3rd(infinity-th?) type of particle, that only exists mathematically, and only in lower dimensional spaces... except we can artificially make materials which behave like their in lower dimensions, and suddenly this particle behaviour emerges!"
That's UTTERLY WILD
And I totally get that we won't understand until you've walked us through the math... but still, come on! That's SO COOL, let us know up-top that the difficult math is heading to somewhere so interesting! 😍
im afraid to even ask how scientist came to a thought that particles might start behaving like in 2d space just by barely constraining their movement in there, i mean they are still in 3d space so why they start to act differently?
@@Andrius319 in condensed matter physics there's actually plenty models - and experimental realisations - that describe 2 or even 1d behaviour!
There are even various theoretical results that prohibit certain phenomena in lower dimensions, search for the Mermin-Wagner theorem. Some methods like the mean-field work better in higher dimension and so on
It's insane how such insane math underlies so much of our universe. This episode, more than any other, made me realize it really IS just maths all the way down. We are insane complex mathematical objects that somehow produce consciousness.
e^iπθ (which is the same as cosθ + i*sinθ) is not that insane. This is especially true compared to the last 100 years of math.
Sadly, Maths are also the reason science as gone so astray. To a bean counter, everything is a bean to be counted....even things that are not beans or countable. Many mathematicians out there have wasted their entire life on theories they can support with math that are pure fantasy, useless in predicting anything, and set back scientific advancement for a generation.
Don’t confuse the map for the territory. The math describes the universe that does not mean it *is* the universe
Ceci n’est pas l’univers
@@fredrikbreivald388 nous sommes les champignons de l'universe!
small error at 17:00, the exponential for an even Eta should equal 1, not 0
Love videos like this. This is the first time I’ve ever heard about anyons and my mind is blown
i know they cite their sources but this whole channel could be making it all up and we would never know
@@yu.niverse naw, I heard of anyons in the late 80's.
It's been 2 months, how's your mind doing?
@@bryanergau6682 re-blown because I totally forgot this until your comment
@@tmrogers87 You're welcome.
I remember reading about that experiment and not really understanding the significance of it at all. This video explains it brilliantly and now I also understand why there are bosons & fermions. Thanks!
man, I really lost you in the middle, but glad I stayed for the punchline! This sounds like the most genuine version of us hacking the universe through our mathematical knowledge I've heard yet!
Congrats! This the first episode that blew completely over my head, lol.
Ever notice how often Limited Time ads are at least partially misscheduled?
Vid: "To get this merch, you have to order by June 23rd." Vid airs on the 27th.
No, this is clever marketing for their time machine. It's been available since 2026.
@@andrasbiro3007 Well, it will have been available, certainly.
@@andrasbiro3007 I came back in time to tell you that it has unfortunately been delayed to 2012.
1:32
Something about dirac belt, su(3), spin 1/2 and covering spaces. There’s a great video by NoahExplainsPhysics
I'm just as fascinated by most of the topics as I am with this show breaking down pretty complex physics in a way basically anyone can follow.
PBS Spacetime: "...that naming an electron is silly."
Me: "Oh, not this again. Eric the 1/2 Electron is not going to be happy hearing them say this again."
Singing.
@@icetraigh Take it away... Eric the Orchestra Leader.
Can we just call them the Tron Twins?
Cyril Connolly.
lmao now i imagine physics professors being fired for using the wrong pronoun for particles in class 🤣
If the universe is holographic and can be represented as a 2D-surface on its infinite boundary, can anyons exist on that boundary?
now THAT is an interesting question, i gotta know!
don't trust me on this (I have no idea what I'm talking about) but I think no because the rules of the boundary would be completely different from the rules of the bulk
Thank you! I had the same question. And if they do exist, how would their interactions play out in the bulk/ higher dimensional space?
Yes. But in that specific case 2 "non-connected" events in either space or time should be able to influence each other if they were connected at some point. I never heard of something like that(~~quantum entanglement~~)
if the universe is holographic, it'd still have 4 dimensions, it would just be a 4d surface on a 5d boundary (I think? correct me if I'm wrong.)
21:00 funny to mention a deadline in video uploaded after it
A video posted an hour ago having a deadline for merch orders 4 days ago. I thought I was having a stroke.
wibbly wobbly, timey wimey
They recorded that merch ad already for the last video and probably didn't bother to re-record. They still wanted to have the ad in there and the information regarding the deadline is not wrong and also still relevant for people to know they won't receive it before July 4.
They are just in a different frame of reference. They go fast.
Get home, open up UA-cam, new episode right there. Nice
Wait wait. These researchers made anyons with spin _exactly_ 1/3, _roughly_ 1/3 or _indistinguishable_ from 1/3? These are algebraically very different.
Genuine question, but how would “exactly 1/3” and “indistinguishable from 1/3” be different?
@@damonedrington3453 By construction. I could do something with the inherent property that doing it three times comes back to the physically enforced integral 1 state, or I could do something approximate with sufficient precision that a test for 1/3 would pass. Something similar happens all the time in computing; rational 1/3 is just not the same as floating 1/3. In physics the rationals are apparently the same ones we use in maths and computing, but floats are replaced by distributions (which are different again from Reals, which are a special-surprisingly complicated-construction invented by mathematicians to make those two notions coincide). If that makes sense?
Exactly, based on the abstract of this arxiv paper: /abs/2006.14115
Assuming youtube doesn't like my comment, the paper is about fractional hall effect, from june 2020
These are quotes from the 1990 paper "Theory of the fractional quantum Hall effect" abstract.
_The main assertion is that new candidate incompressible states can be constructed by taking products of some known incompressible states, and all incompressible states can thus be generated starting from the states at integer filling factors._
_Numerical results show that these trial states very accurately describe the transition from the 1/3 state to the 2/5 state for a four-electron system._
_Even though the fractional quantum Hall effect is found to be possible at all rational filling factors in this approach, it is indicated why the odd-denominator fractions are in general more stable than the even-denominator ones._
It sounds like they're supposed to be exact fractions, just like regular particles. The part about stability kind of sounds like there can be minute deviations, but maybe an unstable anyon just disintegrates or breaks confinement or immediately transitions to a different (but exact) flavor.
2:05 HE SAID THE THING!!!
Came here to post this
said what thing?
@@luudest "Quantum mechanics forbids this", It's a meme
@@LuisSierra42 to be specific, it originated from an earlier episode of this series, so he’s referencing it
@@halyoalex8942 To be even more specific, Matt said it in the video "Why Quantum Information is Never Destroyed" (ca. 4:33) and the text is even written on screen, so a screenshot of that became a meme. I don't think this is the first time Matt has called back to it since it became a meme, but I can't quite remember.
What happens if you keep going up the dimensions? What happens to this concept in a 4D universe? Or a 5D universe? Does it tell us if we can't have particular particles in higher dimensions?
You can always have anyon-like objects, but as you increase dimensions, you need to braid more complicated things to create them.
In 2+1D (confined to a plane), you can braid particles. In 3+1D, you can braid rings. In higher dimensions, you braid higher dimension analogs.
The kind of considerations that forbid anyonic particles in 3D don’t forbid bosons or fermions in higher than 3D if that’s what you mean.
My most favourite astronomy and physics presenter! Thank you !
I'll take one order of fried Anyon rings please
needs to be a t shirt
Going back to school in a week and a half so this is the perfect time to binge PBS space time and get in that ‘sciency’ state of mind lmao
This is a question you should ask physicists, not random UA-cam watchers.
As if physicists aren't random UA-cam watchers too. I am _offended_ on behalf of all physicists!
Going to have to watch this one again. And again. No worries, I've watched pretty much all of the Space Time episodes at least a half dozen times. 😁
such a beautiful explanation, this channel is a gift
This! This is the answer i wanted everytime ive ever asked about spin. Thanks guys
16:50 Unfortunate misprint there, for even η e^(iπη) = 1 as stated, not 0.
Enjoyed the explanation about particles that exist in our 3d world, and the ones which can be created in a 2d environment 👍😊
2:07 Say the line, Bart!
Thank you for including just enough math to force the contradiction! What a beautiful line of reasoning! I enjoyed following your explanation!
Anyons, not to be confused with anions…
LOL!!
This was pretty mind-blowing. One of the most profound conclusions in just about any Spacetime video.
PBS Space Time:
Fermions, Bosons, Anyons
Meanwhile over at Star Talk:
Onions
Probably one of the best yet! Excellent presentation.
I have no clues about what's goin' on yet I watch it every time.... am I normal????
I just ride the wave function through PBS Space Time.
Watch their standard model and standard model lagrangian playlists(in that order) and then watch whatever interests you. If you get through that, you'll catch on soon enough
Are you normal? Yes and no.
@@GhostMop surfing it....
something something particles
This is an absolutely incredible episode. I'm amazed and so grateful for the incredible free learning resource that is Spacetime
Fermions: Minecraft entity cramming limit reached
Degeneracy pressure defeated by placing vines
Telefragging
This is all way above my head, as are most all of these videos. Still find it fascinating to listen to and enjoy every video you put out.
Excellent!
the three-particle version of this can be neatly done on a sphere where you end up with eight copies of the space, one for each octant of the sphere. It's a useful tool for exploring the three body problem.
I thought the main reason I didn't fall through the floor was electromagnetic repulsion between electron shells, which I would think would have longer range than degeneracy pressure. Am I just confused?
you are right, but if electrons could exist in the same state, then they would all fall to the lowest energy and there would be no electron shells. So the electromagnetic repulsion is the direct reason, but it can only happen because electrons are fermions
I had the same confusion.
Consider the fact that electrons within atoms are very tightly packed compared to interatomic distances.If repulsion were the only issue then you could fit around 100 hydrogen atoms inside one uranium atom while in reality only a few will fit.
Charge is powerful; just look at how small of a magnet can fight the gravity of the Earth, but the near-neutrality of matter significantly dilutes it.
Another incredible video! How do you all keep doing this?
After the "kinks" in the last episode, I can't stop looking for these:
11:45 "It Pac Mans to the other side"
Proceeds to draw a Pac Man.
Matt should have worn his Game Over T-shirt.
this subject matter is beyond me. I'm glad there are a lot of people out there who understand this.
My head hurts.
I read this in Monty Python
Modern science really is the magic system of our universe.
Hyper intelligent Mages are probing the deepest most esoteric facets of our reality, and then using special materials combined in very specific and ritualistic ways to exploit and manipulate said reality.
Why are you telling us, in a film released on June 27th, that we must order the merch by June 23rd?
It is the 20th though. Your date settings must be off, or I just found a loophole for playing the lottery...
Its a test to see if anyone has figured out time travel yet
Because time is relative.
I Love PBS Space Time!
I have watched every episode more than once. My mind still gets to thinking now I get it! But then time keeps ticking and things return back to normal. 😊
Keep it up, I'm still viewing!
*Summary*
*The Standard Model:*
* *(**0:11**)* The universe is made of fermions (matter, like protons and electrons) and bosons (force carriers, like photons and gluons).
* *(**1:00**)* Fermions can't occupy the same quantum state, leading to quantum pressure.
* *(**1:19**)* Bosons can occupy the same state.
*Problems with the Traditional Explanation:*
* *(**3:22**)* Saying fermions "swap places" is ambiguous due to quantum uncertainty.
* *(**3:36**)* We can't truly label indistinguishable particles like electrons.
*Introducing Anyons:*
* *(**3:59**)* Anyons are a theoretical particle type, neither fermion nor boson.
* *(**4:19**)* They arise from considering particle movement and interactions in 1D and 2D spaces.
* *(**7:02**)* Anyons have unusual phase shifts when they "exchange" positions, unlike fermions or bosons.
*Anyons in Different Dimensions:*
* *(**10:15**)* Anyons are possible in 1D and 2D universes.
* *(**13:05**)* In 3D (like ours), anyons are usually impossible because rotations would lead to contradictions in their behavior.
*Creating Anyons in Our 3D World:*
* *(**17:58**)* Scientists have created anyon-like behavior by trapping electrons between special materials and using magnetic fields.
* *(**18:24**)* This allows for the study of their unique properties, such as fractional spin.
*Potential Applications:*
* *(**18:39**)* Anyons could revolutionize quantum computing by:
* Allowing for more complex algorithms.
* Enabling more stable storage of quantum information.
*Conclusion:*
* *(**19:11**)* Anyons expand our understanding of particles beyond the standard model.
* While usually restricted to lower dimensions, we're learning to create and manipulate them in our 3D world, with potentially groundbreaking applications.
i used gemini 1.5 pro to summarize the transcript
That’s awesome! Thanks a lot!
God bless you now I'm starting to understand what he was talking about.
Ooof. I can usually at least get the basic idea of these videos but this one is brutal! 🧐
How can we create any-ons in our 3D universe, if the math show that it is not enough to simply restrain the 3D particles movement to a 2D plane. Won’t the mirrored observation effect still make them impossible in some “trapped in 2D” setup in a 3D universe?
Let's consider semiconductors. These are crystals in which an electron can absorb energy, leave its atom, and wander through the crystal
This leaves an "electron-hole" where the electron was, and this hole also wanders through the crystal, and it behaves just like particle with positive charge
Of course from outside the crystal we can see the hole is not a particle and we can describe its effects by talking about the electrons around the hole
Anyons are similar, if we create them they behave as if they had different spin, but from outside this surface we can see that these are just electrons with spin 1/2, and we can describe everything that happens by just talking about electrons
In a sense electron-holes and anyons are "illusions" but the effect they have is real
Mesons are another kind of quasiparticle with the very real effect of keeping protons and neutrons together, and Cooper Pairs are quasiparticles that can transport electric current without resistance
When I saw the title I knew this was gonna be an instant classic Spacetime episode, thanks Matt and PBS team!
Me trying to understand what's being said in this video : *YES*
This was one of my favorite episodes in a few episodes, because you gave us a sense of possibility. Can you do an episode on what it would take to unify or entangle humans with their environment, so that the function of one was transferred to the other in a superposition of states?
I feel like maybe we shouldn't force matters...
Yes
I've just finished a university quantum mechanics course and this video (around the 7 minute mark) finally made the e^(i*theta) phase factor click for me.
haven't gotten even a minute into the video but i had to comment...over the last couple videos, your voice has subtly changed, getting more "growly". i don't know if you are sick, and the videos are all shot close-together in time, but if not i highly recommend seeing a doctor to get fully checked out. voice changes are an early indicator of serious health problems related to the lungs and/or throat.
Ok, Dr. UA-cam.
@@rogertoaster9385 lol, you are probably too young to know who he was, but peter jennings, a news anchor back when there were only a few channels, experienced similar voice changes before he was diagnosed with lung cancer. *always best to know.*
Could also just be different recording equipment, audio EQ/mixing etc.
I literally thought he might be sick and came to comments immediately after starting
It sounds like he has a cold, don't freak out
I must say that was amazing. I don't know if it was due to the help of my background in 3D computer science, but I almost understood everything this time. Thanks.
7:46 wat?
Impressive! We're making particles that can't exist in 3D space. As a complete amateur, i was wondering how thin that boundary line could be. The width of the wave length? Or infinitely thin.
Dark 'matter' may be this particle.
Unless the dark matter is constrained to be on some flat surfaces,
No.
It was more fun when y'all were string theorists.
Wow this is so cool and really simple! I will definitely use this explanation next time someone asks me why we only have bosons and fermions!
Space Time as soon it's available gang
I love your channel to an enormous degree, thank you so so much for making videos!
2:10 he said the line, chat! 😂
Lol, a bot copied your comment and is getting lots of likes
This video blew my mind and really demonstrates the beauty of learning about the universe
All electrons are actually named Dennis.
It would be nice if astrophysics had common names like that.
That's because there is only one electron, and his name is Dennis.
That's true, I met them yesterday on bus.
Not Ellie?
@@jdrobertson42 No i'm dating Ellie they are a proton
1) Wouldn’t gravitons fit the description?
2) Maybe particles are distinguishable physically, but we lack the tools to discern the distinguishing features.
Nice video!
Unobserved particles are in a future state. Because causality has a speed limit (c) every point in space where one observes it from will be the closest to the present moment. When one looks out into the universe they see the past which is made of particles (GR). When one tries to measure the position of a particle they are observing smaller distances and getting closer to the present moment (QM). The wave property of particles appears when we start trying to predict the future of that particle. A particle that has not had an interaction exists in a future state. It is a probability wave because the future is probabilistic. Wave function collapse is what we perceive as the present moment and is what divides the past from the future. GR is making measurements in the observed past and therefore, predictable. It can predict the future but only from information collected from the past. QM is attempting to make measurements of the unobserved future and therefore, unpredictable. Only once a particle interacts with the present moment does it become predictable. This is an observational interpretation of the mathematics we currently use based on the limited perspective we have with the experiments we choose to observe the universe with.
11:56: Particles are categorized as fermions or bosons based on their properties.
01:36: Fermions cannot occupy the same state due to quantum pressure effects.
02:17: Bosons can share states, allowing phenomena like lasers and light interference.
04:19: New particle type, anyons, emerges from rethinking particle indistinguishability.
06:01: Configuration space illustrates indistinguishable particles and their interactions.
08:01: Phase shifts occur in wavefunctions, affecting particle behavior upon reflection.
10:01: Anyons can have any spin, unlike fermions and bosons with fixed spins.
12:01: In 2D, anyons exist due to unique phase shifts during particle interactions.
17:11: In 3D, only bosons and fermions exist due to orientation constraints.
18:24: Anyons show potential in quantum computing, enhancing algorithm complexity.
He can be neither matter nor force if he wants to. He can leave his friends behind.
Yessss, I am so biased, but I way prefer the particle physics to the astrophysics, and we just had that long series on black holes (Though admittedly that did involve quantum mechanics just as much) so it's good to be back!!
Pole position!
Wow. Those visualizations were mind-blowing. How beautiful.
Anyone else feel like those ppl in Idiocracy...? 🙋 😅
Thanks! I'd heard of anyons, now I have a much firmer basis for thinking about them.
Meow! I’m a cat
yes you are !
Hi a cat, I’m dad!
cat until proven wrong :3
Why are you wanna be a cat😅
you may or may not be in a box
At 16:57, the equation e^i*pi*nu = 0 is incorrect, supposed to be a +1.
Small error but still good video!
Can a Particle Be Neither Matter Nor Force?
Every time I fart I ask this same question.
Ah, the hypothetical fartyon, a strong candidate particle for the elusive and controversial "Brown Matter".
Damn. That felt like a geometry-based LSD trip, and I think it was beautiful. ❤
I always suspected Roger Penrose was your visual designer, got you! :D
Brilliant deduction.
Hey there Matt O'Dowd! I am such a fan of PBS Spacetime. You are an absolute Inspiration, at your age. Marvelous!
7:11 Error in reflecting photon diagram. It shows 0 phase change in the photon's wave after it reflects off the mirror surface. In the diagram, the photon hits at its wave's trough. For a pi phase shift, the exiting photon should start at its crest but is depicted as starting at its trough.
I'm just commenting on this to help anyone else who might be confused like me. This diagram confused me when I tried to imagine the same animation of a photon being reflected at shallower angles (think: approaching 180°) and I noticed that the outgoing wave's phase would always incorrectly remain unchanged according to the original animation.
Fascinating episode! This is the kind of stuff that makes me return to this channel over and over again! ❤
I don't understand this but it sure sounds cool!
Really well explained, this is the kind of stuff that keeps me going.
Mind blowing that we can make a two dimensional structure where anyons can exist, and that this could have practical applications in computation. It is almost like we are creating a lower dimensional universe with fantastic new particles.
Wow... this video was just at the limit of my understanding. But it was pretty mind-blowing to learn that researchers have been able to create theoretically impossible particles to potentially power a new type of quantum computer. That's really really cool!
16:51 “e^i•pi•eta = 0”
This is wrong, you meant to put =1
this is a really good video... its kind of insane that we can even produce anyons
I hate geometry in complex space. First time I could not follow the video. Nice one. Something to study this weekend