Can a Particle Be Neither Matter Nor Force? 

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!

"Ok, class... Who can tell me what an η = X particle is called? Anyone? Anyone? Anyone....?"

summoning entities from lower dimensions again

My man just spent 18 minutes explaining how these particles cannot exist and then just casually drops "anohyow, here's how to make them"

Wait . . . what? You explained the Pauli exclusion principle in under a minute? This is what I have been looking for!

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."

Love videos like this. This is the first time I’ve ever heard about anyons and my mind is blown

I'll take one order of fried Anyon rings please

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.

small error at 17:00, the exponential for an even Eta should equal 1, not 0

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!

21:00 funny to mention a deadline in video uploaded after it

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!

As a mathematician, I like how physicists are like beta testers trying to break nature with maths, but good maths always compiles in the end.

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?

PBS Space Time: Fermions, Bosons, Anyons Meanwhile over at Star Talk: Onions

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.

Path integrals can also have situations where momentum is precise but position is imprecise, with phase shifts being close and many paths. Conversely, when momentum is imprecise and position is precise, there will be very inconsistent phase shifts. Due to this inconsistency in phase, the path integrals are likely to cancel out. Moreover, if we do not consider the effect of time on the path phase in a gravitational field, then when a particle starts from a point with a low wave function frequency, precise momentum, and many paths, there will be paths that move away from and towards the center of the gravitational field. Therefore, the phase will change due to the variation in kinetic energy. In regions far from the gravitational field, since the initial assumption is that the phase changes are nearly uniform, the phase change will slow down as it moves away from the field, and speed up as it approaches. This causes the phases in the path integral to start becoming inconsistent, leading to path cancellation. From high to low, the higher the position, the lower the kinetic energy becomes, and the lower the position, the higher the kinetic energy, thus at this point, there are fewer paths but more kinetic energy overlap. The original precise momentum and imprecise position seem to have transformed into precise position and imprecise momentum. When particles have precise positions but imprecise momenta, the path integral in a gravitational field moving upwards with low kinetic energy will have a slow phase shift. However, the further it moves away from the gravitational field, the slower it becomes. Conversely, high kinetic energy near the gravitational field will have a fast phase shift, becoming faster as it approaches the field. It is then assumed that the phases of both will reach a state where they can cancel each other out. Next, consider high kinetic energy moving away from the gravitational field and low kinetic energy approaching it. The phase shift moving away will gradually slow down, while the phase shift approaching will gradually speed up. When the phases align, constructive interference occurs, and the number of paths increases. Starting from the middle path, the higher it goes, the more the kinetic energy decreases, coupled with the higher kinetic energy states, reaching an average. The lower it goes, the more the kinetic energy increases, coupled with the lower kinetic energy states, also reaching an average. It appears as if the path integral has constructive interference, and the phase shifts are close, making the momentum precise, but the paths become imprecise. I would like to ask if this phenomenon exists. Continuing from the previous discussion on the effect of gravitational fields on path integrals, I later realized that when the position is precise and the momentum is imprecise, transitioning to a state where the momentum is precise and the position is imprecise, it is the path integrals with slow upward and fast downward phases that are canceled out due to the path being negated and the superposition of multiple momenta remaining. This results in a precise position and imprecise momentum. Therefore, when the wave function with a precise position and imprecise momentum encompasses all the imprecise momenta in every direction, the upward direction will have a transition from high to low kinetic energy, and the phases will be fast and slow. Since it moves away from gravity, it will slow down, while the downward direction will speed up, also transitioning from fast to slow phases. The issue is that I previously thought that the kinetic energy here was canceled out, but that is not the case at all. So the paths that constructively interfere, as before, will be those where the upward phase is fast but slows down due to gravity to the average, and the downward phase is slow but speeds up due to gravity to the average. The problem is that the upward momentum with low kinetic energy and slow phase shift is not negated, nor is the downward momentum with high kinetic energy and fast phase shift. Thus, at this time, only the paths are reduced due to cancellation. This indicates that the state with imprecise momentum and precise position coexists with the previously mentioned paths of constructive interference, where the position is imprecise and the momentum is precise. I’ve just realized this now, and it indeed produces a very interesting phenomenon.

This! This is the answer i wanted everytime ive ever asked about spin. Thanks guys

2:07 Say the line, Bart!

such a beautiful explanation, this channel is a gift

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!!

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.

This video blew my mind and really demonstrates the beauty of learning about the universe

This is the most sci-fi episode of space time. This is like exotic futuristic materials

Enjoyed the explanation about particles that exist in our 3d world, and the ones which can be created in a 2d environment 👍😊

Minor correction on the anyonic realisation cited: it's not the first time they did so, it's a continuation on an experiment 4~5 years ago that produced anyons of spin 1/3 (or maybe 2/3? I can't tell). This time they got a spin of x/5 (still can't tell what x is).

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.

At 16:50 Matt says that fermions have an odd Eta and bosons have an even Eta in terms of the phase shift. This seems really similar to saying the Eta is double the spin. Is that a real relationship? In fact, what's the reason spin is measured in halves anyway? Using this even/odd rotational distinction makes a lot more sense at least to me.

Hey there Matt O'Dowd! I am such a fan of PBS Spacetime. You are an absolute Inspiration, at your age. Marvelous!

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?

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

Its really cool that we can figure out that these impossible particles could exist and then making them exist.

At 16:57, the equation e^i*pi*nu = 0 is incorrect, supposed to be a +1. Small error but still good video!

This was pretty mind-blowing. One of the most profound conclusions in just about any Spacetime video.

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.

Dark 'matter' may be this particle.

I love when you say "frankly awesome video!"

This sounds like a good reason for our universe to have three dimensions of space ; this is the most complex possibility.

This is pretty amazing that anyons were hypothesized then created in real life.

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.

I like the new Spacetime Intro segment. I was thinking it needed an upgrade.

When I saw the title I knew this was gonna be an instant classic Spacetime episode, thanks Matt and PBS team!

this subject matter is beyond me. I'm glad there are a lot of people out there who understand this.

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.

2:10 he said the line, chat! 😂

Wow. Those visualizations were mind-blowing. How beautiful.

Space Time as soon it's available gang

Another incredible video! How do you all keep doing this?

All electrons are actually named Dennis.

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.

This short-circuited my brain. It feels like math explaining the universe explaining math.

This is one of the most insane things I've ever heard on this channel. So we are literally forging new exotic particles that don't exist in our universe

Would they be possible in a 3+1 spacetime IF we considered this from the context of spacetime being emergent from 1D conformal fields on the universe's exterior? Along the same train of thought, what might those researchers' discovery (metal/electrons) tell us about the physics of those conformal fields?

To be honest, I was most surprised that fact that we can mimic 2D-Space in real life. Not like a model, but actually having real electrons behave like they are in a 2D Universe. :O

Pacman as a verb is gold

Could anyons exist on the surface of neutron stars? The intense gravity could squish the local environment down to a 2D-like situation.

Can a Particle Be Neither Matter Nor Force? Every time I fart I ask this same question.

I find it funny the particles adapt behavior to the experienced dimensions, even while they exist in a higher-dimensional space. It seemingly proves that the true dimensionality does not really matter and we can simulate any lower-dimension than our own and gain whatever benefits that offers. For computation, energy harvesting, conversions and chemistry. Maybe even more.

Anyone else feel like those ppl in Idiocracy...? 🙋 😅

Incredible finding (and video about it)! Do we have an explanation though as to why the experiment produced only 1/3-spin electrons (as opposed to *any* other spin)?

"We live in a conveniently simple universe" might be the funniest thing I've ever heard Matt say

this is a really good video... its kind of insane that we can even produce anyons

e^ipi is one of the most beautiful things in mathematics.

so does this mean we can rule out higher dimension universes because of the specific spins of particles that we observe, or does the math shake out the same in n+1 dimensional space where n is larger than 3?

this is a pretty good explanation for what happened to hughies dad in the latest episode of the boys

We're like Mario trying to figure out what pixels are made of.

I don't understand this but it sure sounds cool!

I hate geometry in complex space. First time I could not follow the video. Nice one. Something to study this weekend

I find it strange to assume that because two particles are indistinguishable in their properties, that we then conveniently forget we **have** distinguished them insofar as we label them electron 1 and electron 2 in the exercise. If we hadn't labelled them, then there would only be one electron. It's like forgetting the most basic geometric reality in favor of particle properties. "We cannot distinguish the difference between" does not mean you can create a force for no other reason than the math looks the same in both cases. There are 2 electrons, and we have no reason to think there is a force making them retreat, so there isn't. If one day we find evidence this occurs, then by definition, we will be able to distinguish between electrons passing through one another and retreating from one another. But here proponents of the theory simply redefine a particle passing through another as a reflection of some kind. The force you've created IS the current indistinguishable-ness of the two particles, in a way. There is no added value to describing things this way.

Matt:"We can't have anyons in our 3D universe. " Me: "Makes sense, nice dream tho." Next sentence: "But scientist have created them..." Me: "Omgwtf. :D"

Oh hello Lord Larys!!

Interesting. I wonder if something similar could describe why there are only 7 charges for quanta.

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!

Imagine if this was all a simulation. Some guy is running the computer sim like we play the Sims, but he sees how the universe plays out if he were to increase the mass of a proton by 1% vs a decrease of 1% or how Fermions interact.

When he said Nord I got those IH vibes, come back to us sensei.

The 3D phase shift problem reminds me of branch cuts with imaginary logarithms

Such a cool explanation. Clear, concise and so interesting. 19:43 Fascinating stuff. (Ps - love my glow in the dark Higgs B T shirt)

A black hole is a graviton, the smallest particles and the only ones with negative mass, the so-called gravitons are miniature black holes that repel each other due to their negative charge, a black hole is a zero charge, when a star collapses it combines matter (positive charge) and anti-matter, gravitons (negative charge), then the excess energy is jets. There must be the right temperature and mass to create a long-lasting large black hole, smaller ones must disintegrate into the smallest particles, smaller like the strings from which matter exists. Due to their negative charges, gravitons (miniature black holes) repel each other, creating an expanding universe, which thins out faster the more small repellent gravitons there are. You have to look for negative mass to find gravitational waves that are created by positive matter and carried by negative matter, filling the universe. That's why there is a limit to the speed of light, because you can't go faster in negative gravitons

wow, I think I found first time going to lower dimension opening up new scopes. Can you please refer to the work by the French research team. Thanks.

Could you discuss the biverse theory of cosmogony? Do they necessarily have exactly the same events or do they evolve with separate quantum randomness?

I thought all the particle families dropped out of there being symettries to the universe, and there's only so many symettries you can have

Now THAT is a proof for the Simulation, there is no way this is not a weird bug exploit!

2:07 it's back!!!

Why do i watch these at night, when my brain easily turn into mush, all this math dosen’t help - but I do think I understood at least some of it today 👍🏻💪🏻👏🏻

Real good explanation! Thsnks❤

Most weird idea from PBS Spacetime. However Neal Stephenson described this strange matter in his post futuristic neo scholastic novel Anathem.

(Not related to this episode, just commenting most recent video) I have a really theoretical question which I hope you could answer: Is it possible to see behind the cosmological event horizon by launching a telescope spaceship towards it (any direction into the Abyss^W Universe) with a good fraction of speed of light, while maintaining Earth-ship communications? I think we on Earth could connect to the ship, of cource, experiencing increasing communications delay due to distance. But the ship itself should be able to see some things 'redshifted into infinity' by universe expansion.

Matt, anyons don't break the Universe, only our brains! This is why we have to rewatch your videos five times in a row, so that we can understand it at all. Clever strategy to get more views on RU-vid if you ask me! 😂

My theory is the Universe is built on Both the "individual" and the "relationship" of existence.

That episode was a banger!

If you think about it we have force carrier particles, and non-force carrier particles. By the logic here a type for neither and a type for both should exist. So something that is neither matter nor force and something that is both matter and force should theoretically exist.

Empty Space is both solid and empty as it consists of electrons and positrons in superposition - the Polectron Field cell - which is neutral, so very small (Planck Length(s)).. Each bonds to 12 neighbours, as if they were touching close-packed spheres.. Full Split Energy splits field cells into separate, entangled (loosely bonded) electron-positron pairs. No Quarks, an elastic, mostly empty space(time) distorted by matter that is made up of electrons and positrons.

A particle can be whatever it wants and puts its mind to, and I won't stand anyone telling it otherwise.

Are Anyons similar to the particle type known as Noneyas?

If fermions are a group of bosons bound together by the Higgs field, and bosons are massless and able to pass through each other, then there could be a way of describing the singularity of a black hole. The fermions' repulsive forces are overwhelmed by gravity and they unify into a ball of various bosons. This would enable them to occupy a much smaller space than the space needed in a neutron star. This also means that there is no infinite singularity inside a black hole, which we already know cannot happen. The infinite singularity is just a placeholder for the point where Einstein's physics breaks down. I am not sure what fields need to be overwhelmed by gravity besides the Higgs field.

There's a typo on the slide at 16:50. The first quantity should be 1, not 0.

what a time to be alive =]

So... what you're saying is that there is an infinitesimal space just above the event horizon of black holes where anyons just... exist, and don't bother anyone, just whizzing around the entire radius of the black hole doing their anyon thing?

Not sure what to make of this. I don’t agree that the standard analysis is flawed. I don’t see why it had to represent a physical process of moving the electrons, rather than an abstract “swapping of labels” between them. I don’t see why these guys think indistinguishability isn’t respected. The whole point is that however you label them, the bipartite wavefunction is unchanged up to a phase factor. The simplest explanation of why there are no anyon is that the exchange operator fundamentally has only two eigenvalues: +1, -1. There mathematically is no other way This just seems to me like a very complicated explanation of something that is already apparent. I don’t think that the normal explanation is even wrong either. But I guess it is interesting that anyons could exist in lower dimensional universes