Could the apparent dominance of "regular matter" in the universe be just a local phenomenon? Like, it just so happens that there was more matter than anti-matter "here", and elsewhere in the universe there is a local surplus of anti-matter? Could very distant galaxies be "anti-galaxies"? Would we even be able to tell?
I remember an explanation that this is unlikely, as there would have to be some delineation between matter and anti-matter galaxies, and at this boundary the small number of particles drifting across would produce detectable photons. But I've been out of academia for years and the the universe is big and weird, so take my comment with a pinch of salt.
I think the rough explanation is that empty space is not empty enough to be hiding antimatter galaxies. There's enough junk in the void that you'd be able to see some evidence of annihilations.
@@tomf3150 What does that mean? CMB radiation can be explained by small variations amplified by inflation, why wouldn't the same work for matter-antimatter proportion? It's even proposed to be a one in a billion variation, which sounds like plausible for expanded noise.
@@altrag idk, it's pretty exciting when you know you're missing something, but everything you test lines up with current models. So with each test you're narrowing things down and getting closer and closer to the missing piece(s). The next experiment could always be the one that changes everything even without breaking our models to pieces.
5000 years from now, mankind has mastered the universe and generates free energy by altering the laws of physics in an area at will, we are capable of traversing galaxies in seconds, and we can instantly fabricate anything from thin air with a mere thought. Somehow, nobody can afford printer ink, still.
5000 years from now on is too small for that bro,maybe 5-50 million years if we survive till then, besides some thing's which you are mentioning aren't possible by the current laws of universe as we know now so .....
For those who are wondering where antimatter actually IS: It’s the ink inside printer cartridges. That’s why when it meets your printer, it annihilates itself, and reads empty, despite you JUST buying it.
Virgin Baryon: has mass because his existence is heavy, experiences time as an arrow Chad Photon: already annihilated, chilling at the speed of light in an eternal present, only experiences time moving forward when he interacts with something
What I'm essentially getting from this is: "If it weren't for an imbalance of matter & antimatter, there wouldn't have been enough matter to have formed the universe that birthed us. Matter-antimatter annihilation releases photons. There are a billion times more photons than matter particles. If the antimatter-matter distribution had been symmetrical then that number would be far far greater, such that the chance that matter particles would encounter each other would be nearly impossible except for in small isolated groups without the gravitational pull to form stars or planetary systems. As the universe expands & cools down, the chances become even less. A perfect imbalance of antimatter allowed us to exist. The entire universe is a lucky Goldilocks Zone. Not just on Earth. If the multiverse theorem is correct, then this is just one version of an infinite number of universe possibilities where only a limited number are capable of forming & supporting life in whatever form it may be.". Any major misunderstandings?
But the problem is far worse than an insufficient imbalance to explain the rise of the observable universe. Rather it is this: Why is there any imbalance between matter and antimatter at all? Anti-matter should exist in a quality precisely equal to that of matter, unless they are not perfect mirror-images. So far, though, even to a high degree of precision, they are perfect mirror images. There is a solution but it is theoretical: all violations of charge-parity symmetry are offset by violations of time symmetry (i.e., causation does not run exactly the same in reverse, as seen in experiments involving kaons), and if the offset between the two symmetry violations (CP on the one hand, T on the other) may itself be viewed as a symmetry (i.e., CPT symmetry). This solution has been around for decades , but it seems contrary to traditional physics, right up through the Theory of Relativity and its notion of space-time, which recognizes no asymmetry in time. But if we could find a way in which matter and antimatter were not mirror images, the whole problem would seem soluble. So far, though, no such luck.
@@Primitarian I'd like to know why the possibility that there was simply more regular matter created than antimatter in the first place is off the table. Idk enough about this stuff
@@Primitarian I have a theory that can explain why matter and anti matter are exact opposites, but, it requires a different way of thinking. what's going on is beyond us all and may never be proven, When you consider how big the universe is, and how much space you do need to be able to give the universe a place somewhere as existence (matter) but there is actually no possibility at all to create a universe (matter), then you have to assume that the opposite is necessary to give matter (the universe) a place as existence If there is the possibility to create a universe (matter), while there is no need for space thanks to anti-matter, the possibilities are endless as currently the universe is still expanding from the big bang, thus, anti-matter is still present in the same amount as matter to give the universe (matter) an existence in an anti-material enclosure.
Re: baryon asymmerty: suppose the universe is either infinite or at least 10^large times larger than the observable part. Could it be that we just live in a sector that was randomly antimatter-poor because 10^large particles and their 10^large antiparticles probably won't have identical average momenta? So all the antimatter is just literally outside of our cosmic horizon? Could it be that, like our distant descendants who won't be able to see galaxies or the CMB, we just don't have access to observations that could solve problems like this?
I argued about that some time ago and my answer is: No, since our observable universe is isotropic in a large volume. Our existence in a local patch of 'regular' matter would not require that: A far smaller volume of relatively isotropic 'matter' could allow for our existence. Assuming the distribution is like that by chance, the probability of a patch of 'regular' matter with a volume < 1 GLy³ would be extremely much more likely to be where we find ourselves than a patch of isotropic 'regular' matter of the size of our observable universe with thousands of GLy³.
@@roblaquiere8220 Isotropic on large scales. The earth's mantle and the near void of space of very different, cubic meter for cubic meter. Galaxies and galaxy voids are equally different, 100-cubic light year to 100-cubic light year, and the observable universe is only about 9*10^10 light years across. If this discrepancy only presents itself at scales similar to 10^100 light years, would only being seeing .0000000000000000000000000000000000000000000000000000000000000000000000000000000000001 times thescale necessary to detect this anisotropy. Just saying.
@@kindlin It'd be very unlikely that we'd exist in such a large patch though, smaller patch much more likely. The fact our patch is so big suggests that the universe is isotropic at large scales.
@@kindlinTo produce a local overabundance of at least ~10^80 matter particles (in the observable universe) by chance, the original number of particles and antiparticles would have had to be around 10^160. This is impossible because 1. the energy released by their annihilation would be far higher than we observe, and 2. annihilation must have ended by about one second after the Big Bang, at which time the observable universe was far too small to contain that many particles (it would correspond to about a million particles per Planck volume).
"ALPHA uses CERN'S proton synchotron to get their anti-protons; The synchotron accelerates protons to 10s to 100s of giga electron Volts of kinetic energy, corresponding to over 99% of the speed of light" is the most amazing sentence I've ever heard on any UA-cam video ever. It sounds like the most crazy ridiculous scifi nonsense ever, but it's COMPLETELY REAL
anti protons are notanti matter, anti protonds are just as simple as the opposite poles of a freaking magnet.... and dont be so fond of the 99% of speed of light at cern, it is nothing compared to the 99% of speed of light, in those regions of the universe that are vastly empty... observing the speed of light on earth cpmpared to speed of light there , is as if watching a microbe racing vs a formula 1car.
@@AbyNeon God you must be fun at parties. First of all antiproton is an anti-particle, and the fact that speed of light in vacuum is way more doesn't change the fact that reaching 99 percent speed of light here on Earth is absolutely insane and dont get so "fond" of your knowledge there are people out there(mostly in this comment section) who would make you feel as smart as a bag of sand. If its about comparison so much then relatively youre a fkn donkey mate.
Anti-matter: "So..." Matter: "So what?" Anti-Matter: "ARE WE NOT GOING TO EXPLAIN THE ELEPHANT IN THE ROOM?" Matter: "What, I don't see anything?" Anti-Matter: "ITS LITERALLY THE BIGGEST THING HERE!!" Dark Matter: "Who, me?"
@@vitorfalcao5969 There is an episode in this series about Axions which were porposed as a solution for the strong CP problem as a consequence of Peccei-Quinn mechanism. Check out the episode so you'll understand how it is relevant.
@Astute Cingulus There has been recent evidence for possible Axion detections the issue is we can rule out minute traces of Tritium contamination and radioactive decay and the detections are still only just over 3 sigma
I wrote a scientific paper on antimatter, but my anti-dog ate it. Then the paper and the dog were anhialated when my containment field collapsed due to an unpayable electric bill. There were no survivors.
@@esquilax5563 Actually no, an average dog would release enough energy to power norway for a bit over 2 years if it combined with the same mass of antimatter. It will uld make a sizable explosion but we wouldn't all die.
Matt, would you mind going deeper on why CPT transformation changes a particle into its anti particle. On the surface it would appear that would result in the same particle, since C transformation would flip the sign. And then T transformation would flip the sign once again, since a positive particle moving forward in time should behave just like a negative particle moving backwards in time.
I had no clue we haven't already tested how antihydrogen behaves in a gravitational field. It is absolutely bonkers that we don't know yet and I'm super excited to find out whether or not they go up.
@@volkhen0 duh. But then again, I really hoped that experiment to test for higher spatial dimensions would turn up a number higher than 3 but that didn't turn out either
Imagine seeing a copy of yourself walking backwards through the door, turning around and looking at you, and standing in front of you with its back to you.... knowing your fate is to stand up and walk into your copy... at which point you start to experience time backwards.
There's a scene in this one book (a parody of another one but teaching quantum mechanics) in which the character is walking forward, sees two copies of him/herself appear, collides with and becomes one, goes back in time while still walking forward, and then collides with and becomes the other.
I'm in the middle of a Star Trek:Enterprise binge , and this talk of antimatter is "like, yeah bro, tell me something new, now let me get back to adjusting those antimatter injectors", but I never knew that antimatter containment of anything more than microseconds was actually a real thing. Thanks for another great video.
Yeah this is a surprising conceptual mistake in the video. CPT is the identity operator by the CPT theorem. T sends particles to their CP conjugate so CPT=CP(CP)^{-1}=I. You also do not need CPT violation for matter-antimatter asymmetry. Many physicists today think that maximal CP violation in the neutrino sector is quite likely to allow for a process known as leptogenesis whereby CP violation in neutrinos combined with a strong first order phase transition sometime around when the universe cooled from the plank scale to the electroweak scale allowed an excess of matter to be generated via B+L number violating processes like sphalerons.
I think a better explanation for this video would be something like the following: You can think of C, P and T as the sides of a triangle where the vertices correspond to the different states you can get by starting from a chosen state and applying C, P or T. This works because C, P and T are all their own inverses, ie C^2=P^2=T^2=I and they commute with each other. For example, CPC=CCP=C^2P=IP=P. The CPT theorem is a proof that in any locally Lorentz invariant unitary quantum field theory the triangle must be closed, ie CPT=I. If there was CPT violation (meaning CPT!=I) then CPT wouldn't quite take a state back to where it started which can only happen if you violate local Lorentz invariance, unitarity (you can think of this as probability conservation, meaning the sum of probabilities for all possible outcomes of an experiment should be 1) or both.
Sunshine Daniela yup! I’m a big fan of both finite and Lie groups and their applications to physics :) I highly recommend Peter Woit’s text book “Quantum Theory, Groups and Representations”
One interesting fictional take on antimatter is in Greg Egan's Orthogonal trilogy. Matter that's been round the universe and odd number of times (relative to you) ends up as antimatter. You can, however, safely interact with it if you get your state of motion such that your arrow of time points in the opposite direction to it. Actually, the whole universe of that trilogy is just fascinating, and Egan spends at least as much time on the characters discovering the physics of their universe as whatever human-like conflicts they have with each other.
been watching you for years. just spent 15mins finding out what your name is and where you worked. maybe i can get an autograph whenever i visit new york some day. you've been putting me to sleep for years but not in a bad way. you're always the last thing i watch before going to bed as my mind wonders about your lectures. thanks Matt for all you do
If anti-matter can be "viewed" as matter moving the opposite direction in time, then why can't the asymmetry of matter and anti-matter after the big bang, be explained by the anti-matter just going the opposite direction in the time dimension?
@@flakmagnet9357 I suppose that would be impossible to know then. Because even if it was true and we managed to create a time machine we would never be able to go further back then the Big Bang and come back to tell the tale (if for no orther reason, because we would found ourselves made of matter in a universe of anti-matter and would probably be annihilated pretty quickly). At least that's how I see it.
The "T" reflection is for laws of physics, the particles don't literally go back in time (at least we think; not much research has been done on antimatter).
I'm rooting for anti-matter to have anti-gravity. I posited it decades ago when I was in college as a solution to the problem of why there were not equal amounts of matter and anti-matter observable in the universe. Anti-gravity would cause anti-matter to segregate itself from matter into discrete clusters, even to the extent of discrete clusters of galaxies. Ironically, I scrapped the idea because it seemed to me that the net repulsive gravitational force would lead to the acceleration of universal expansion, which was not even considered possible at that time.
@@NitpickingNerd That's not actually true experimentally. We have only produced tiny amounts of anti matter and we cannot measure how they gravitate. From the theoretical standpoint there is no reason at all for antimatter to behave gravitationally in a different way than matter I agreed with that, but you cannot say that as a true fact because we haven't seen masses of antimatter large enough to test gravity with antimatter. There is the big bang theory though which is extremely precise in some of its predictions and it assumes antimatter gravitates in the same way as matter does. Antimatter gravitating differently would produce peculiar signatures in cosmological observations and we haven't observed them, so yeah from this point of view you can say that we know experimentally that antimatter gravitates normally
Thanks to the speaker for slowing down in this episode. I have loved the information in these episodes but the speaker was so fast that I could not understand much. Loving this now
Using the LCH to make antimatter is the most roundabout method I can think of, why not use a basic gamma ray laser that can be made with any laser and some magnets, if you want a specific antiparticle, just change the frequency of the laser.
Why does matter and antimatter annihilate each other? Apart from "because the mathematics say so", is it possible to give a more intutivie explanation for the phenomenon?
It's not just math, home.cern/news/press-release/cern/first-atoms-antimatter-produced-cern I struggle to find a real intuitive answer to that question, and what you find intuitive. An analogy would be 2 substances, that when put together will react and explode. Also don't think that they disappear if they come together, but "explode" transforming into radiation. At least that's my understanding of it. But I'm no physicist, so don't listen to me :-P
The process of creation is a little more intuitive. Energy can take many forms and one of those forms is matter, as Einstein showed. Therefore, when there is a lot of energy left over, matter can spontaneously appear. Because however, certain properties such as charge are conserved in space, whenever a positively charged particle appears, a negatively charged particle must also appear to compensate. This would be our antimatter. Whatever happens at annihilation, is the exact opposite and reversed process of this creation. I have not really studied Quantum Field Theory yet, so I do not know the math. Maybe someone else can give a better explanation of what is going on under the hood.
It's about as deep as asking why matter exists. I can't think of a more fundamental way than the laws we make for real matter predict it and we observe it. A little more insight is that in classical laws concerning mass, i.e relativity and general relativity, the laws behave differently for a negative mass/energy and so there are axioms to say this cannot happen. Reasonably so as otherwise there would be some crazy objects running. Now you may know E =mc^2 but it is actually an at rest equation. The true one is E=sqrt((mc^2)^2+(pc)^2). That's funny because from high school you know a square root has plus and minus. This is going to be mathsy, but remember the maths is self consistent and relates to a physical thing. Of theorists do there jobs right and nothing is shown to counter it and the result is observed, its physics. Maths is logic but hard to understand and easy to do. SO the time dependent schrodinger equation is non relativistic. Look it up for its form. But the time derivative relates to energy, the space derivative to momentum (E=p^2/2m=0.5mv^2). If you plug the same ideas into the Special relativity equation above you, after some work you get the Dirac equation (Klein gordon did it with a second order time derivative (E^2) but that was all sorts of wacky, things affect you outside the light cone and if p->0 it did not resemble the schrodinger equation as it should at low speed/momentum). The Dirac equation. Look it up. Works very well, but still has negative energy solutions. However when you plug these solutions into the equation and include spin (or chirality [spine parallel to the direction of motion] more generally) the negative energy solution behaves as a positive one with opposite spin/chirality and charge. So in quantum mechanics our negative energy solutions are in fact objects with opposite quantum numbers that behave with positive energy *but* are still distinct from the normal matter states. Here is when it's a bit beyond me. Dirac thought of this that a vaccuum is in fact relative and there is an infinity sea of lower energy, or negative energy, particles below. When a particle is created it is excited from this lower state. The empty lower state is the anti particle (why they come in pairs) and has opposite quantum numbers. I don't know why they behave like normal mass. The *real* modern interpretation is in QFT, sorry but I do this course next semester and will get back to you.
Haha using antimatter for hoverboards would be ridiculously irresponsible. The better use would be as negative mass for warp drives. That way towns won't disappear off the map after every hoverboard accident
Wow that was interesting! It’s amazing what mankind has achieved. Those CERN experiments are so fascinating. Thanks for translating that research into human language, Matt 👍🏻
Wow, Matt! An episode of PBS Space Time that I feel I fully comprehended! . . . "In a wee bit after the beginning, G-d said, 'Let the number of positrons be one less than the number of electrons', and, lo, it was good, really, quite good"
Matt: Could the difference in mater to antimatter be linked to the curvature of spacetime? If quantum fields arise from some microscopic topology of spacetime they would have "width" like a soap bubble on the surface of water. If the universe were to have positive curvature the "inside" width would have slightly less volume than the "outside" width especially closer to the big bang when the curvature was greater. So if anti/mater particles form on opposite sides of the spacetime sheet, particle generation might be biased towards the side with greater volume while still preserving the chirality of all particles. Maybe the disparity between mater and antimatter is proof that the large scale curvature of the universe is not flat. Who knows, just the rantings of an armchair quantum physicist.
Are you an actual quantum physicist? This idea seems so elegant I hope it's true. Two super nice and symetrical ideas (a sphere and waves of curvature in opposite directions) combining to make the asymmetry we see in our universe. I imagine you might actually be able to calculate how small or large the curvature would have to be for this idea to work
Actually, I just did the calculation on this assuming the universe is a 4-spherical shell embedded in 5 dimensions, as well as another assuming it's a 4-cylinder shell (infinite in time). Assume the particles (topological deformities) have a small width, say t. For the proportion of matter to antimatter to be off by one in a billion, the radius of the universe would have to be only 3 to 4 billion times the width, t. That's not nearly large enough to account for measurements that show the universe is demonstrably flat up to our measurement capacity. The universe is more than 40 billion lightyears in radius, so t would need to be about 10 lightyears, which is ludicrous. So my back of the envelope mathematical understanding says this theory is probably not correct. But I really am no physicist - just doing the math
2:55 I think you meant that if you apply a CPT transformation to a particle you get itself. For example, if you do just a CP transformation on an electron, you get a positron spinning the opposite way and moving in the opposite direction. Apply a time-reversal transfomation to this and you essentially get the same electron you started with. For another example, if you do a PT transformation on a proton, you get an antiproton going in the same direction and spinning the same way as you started. Flip the charge ans you get the proton you started with.
The question of why there is something rather than nothing is one of the most profound in cosmology and philosophy. Antimatter, the counterpart to ordinary matter, has been proposed as a potential key to understanding this mystery, but the answers remain speculative and complex. In the context of the universe's origins, the current leading theory is that the Big Bang initiated the expansion of the universe from a singularity, a point of infinite density and temperature. During this event, equal amounts of matter and antimatter were created. However, when matter and antimatter meet, they annihilate each other, producing energy in the form of photons. If the universe began with equal amounts of matter and antimatter, we would expect complete annihilation, leaving behind only radiation, with no matter to form galaxies, stars, or life. The fact that the observable universe is overwhelmingly composed of matter and not antimatter suggests that there was a slight asymmetry-known as **CP violation** (violation of charge conjugation and parity symmetry)-in the laws of physics that favored matter over antimatter. This asymmetry may have allowed for a tiny excess of matter to survive after most of the matter and antimatter annihilated each other. The exact mechanism behind this matter-antimatter imbalance is still one of the greatest unsolved mysteries in physics. Now, can antimatter help explain why there is something rather than nothing? One hypothesis is that the presence of matter, rather than complete annihilation, points to unknown physical processes or forces at play during the early moments of the universe. The existence of antimatter and its interactions with matter could be a clue to deeper symmetries or properties of the universe that we have yet to uncover. For instance, some theories suggest that the existence of antimatter might indicate that there is a hidden universe of antimatter that mirrors our own, existing in a way that is not immediately detectable due to our own matter-dominated environment. Moreover, questions about why the universe exists at all can lead into even more speculative realms of physics, such as multiverse theories, where our universe is one of many, each governed by different physical laws and conditions. In such scenarios, the laws of physics in our universe might be uniquely suited to allow for a matter-dominated cosmos. In conclusion, while antimatter provides insight into the asymmetry between matter and antimatter, it does not alone answer the profound question of why there is something rather than nothing. The imbalance may be a crucial part of the puzzle, but it is likely that a complete explanation will require advances in our understanding of fundamental physics, including quantum field theory, particle physics, and cosmology. It may even point toward entirely new theories that merge the macroscopic and quantum realms, seeking to answer not just why the universe has the properties it does, but why it exists at all.
Is there any measure confirming the whole one in a billion chance of matter to "survive" annihilation with anti-matter? To me it always sounded like random pre-inflation variations in matter-antimatter proportions should be able to explain the difference. Has it been ruled out or is it just that physicists don't like that option?
If matter and CPT shifted matter annihilate, what happens if matter and semi-shifted matter interact? Do they partially annihilate? What is left over if they do? Or what is made if they don't?
At a very small scale, they either have decayed or not. The rate of decay is predictable on a large scale, but at the individual atom level it is not, and rather has a probability of decaying or not at any given point in time. As such there is no such thing as "partial decay" unless you are talking about large atoms decaying into multiple smaller atoms.
@@elinope4745 is matter-antimatter annihilation decay though? I though decay was spontaneous and random, not the interaction between two distinct atoms
The CPT symmetries are though experiments rather than actual physical processes that can happen to a particle, so it doesn't make sense to ask what would happen if a particle was semi-shifted.
I do have a question about this problem, if the mass of the particle and antiparticle are equal, but the charges are opposite, could this be solved by the different spin, meaning if they started out moving in a similar direction, could a weak change the left handed one into something else, causing a cascade effect where only antiparticles where left-handed in their pairs, effectively transmuting antimatter into matter of a different charge?
Old joke (from 2012 when LHC was launched): "Particle scientists love to make meetings every 10 to 20 billion years and launch some powerful particle accelerator..."
I genuinely believe the best thing about the PBS videos is the comments section, & people copy & pasting from lesser known texts pretending to know what they're on about. It's great. Maybe though, we should just accept that 99% of us don't actually understand are just attempting to educate ourselves.
Thought experiment I can't figure out the answer to: if a black hole made of matter somehow collides with a black hole made of antimatter, would they annihilate? Or would they merge into a bigger black hole as normal because only the mass matters? If they do annihilate, would that create a Kugelblitz because all the particles inside are now photons? Or would the photons created violently rip the system apart, overcoming gravity?
Whatever happens it cannot escape the event horizon, so from outside it would remain just a normal merged black hole. Inside? We don't even know if matter exist or if even something exist inside a black hole normally
@@WaveOfDestiny This is a black hole in the midst of colliding , so if I'm not mistaken the event horizons would kind of stretch out until finally they merged, perhaps leaving a short time that light could escape and be measurable? Or is the process of merging continuous such that the two event horizons meld into each other without ever shedding any matter?
If high enough energies can make a random bunch of particles (like in the LHC), can't the matter-antimatter imbalance be the result of probability? They could both have the same probability to be made, but we ended up with more matter by chance.
My bet, CPT symmetry holds but antimatter and matter are not related by a CPT transformation, you also have to invert the mass. Contrary to the common belief, a particle with negative mass would not "fall" upwards in the presence of a dominant positive mass gravitation field such as the Earth. The geodesics of spacetime are the same. The difference is that the Earth would at the same time be repelled by the negative mass, but if that mass is on the order of a proton, compared to the Earth, the only effect would be that it would appear to fall slightly slower, which is actually supported by the latest evidence. Antimatter having negative mass means that it would repel other antimatter and thus could not condense into stars, galaxies and whatnot. Rather it would spread out into a diffuse fluid, and form halos around clusters of positive matter. This asymmetry explains why the universe *appears* to have more matter than antimatter, while also going a long way to explaining dark matter and possibly even dark energy. Not my idea, there is a great paper all about it.
A little delayed here but I have a question. If the Andromeda galaxy were made of antimatter, would we be able to know it? I guess it boils down to, does antimatter give off a different kind of photon than normal matter. Just curious. Thanks.
Wouldn't they travel the other direction through time, so they would be on the other side of the big bang? Ex. My anti-counterpart would exist 26 billion years in the past.
Extending time "through" the big bang is problematic at best, and utterly absurd at worst. On the other hand, if you take time as an imaginary axis, the euclidean metric actually lines up with the spacetime interval. Since i and -i are algebraically indistinguishable, that would make the behavioral symmetry of antimatter quite obvious. If you take the big bang as the origin event of this 3real+1imaginary spacetime, all the antimatter lives "below" space in the negative imaginary axis. Probably wrong, but it's a pretty thought, at the very least.
Antimatter particles moving backward in time is more of a description of what the laws of motion for antiparticles are rather than it is an actual declaration that they somehow violate causality and truly travel backward in time.
@@Nosirrbro Check out Andrei Sakharov's model of Cosmology, where the arrow of time is reversed before the Big Bang. en.wikipedia.org/wiki/Andrei_Sakharov#Particle_physics_and_cosmology
@@fortuna19 It's motion is opposite relative to ours. Why are we moving "forward" through time? For every direction you travel, you are also traveling the opposite direction but with a negative sign. Moving 20 km north is the same as traveling -20 km south.
I literally audibly exclaimed when he mentioned we can make stable atoms of anti-hydrogen that last DAYS. I would have been impressed if they lasted half a minute! It's amazing the kinds of extreme science we're able to do right here on Earth! Really excited to see what results ELENA finds!
Better Call Saul is such an underrated show... the last few seasons are god tier. It's Breaking Bad all over again. The show is getting better every season.
I always had this crazy idea that the universe could be infinite. The rebuff to this was that an infinite universe would be unbearably hot because eventually it would fill up with photons. Then I realised that would just make a whole stack of koogleblitz(?) Black holes and they wouldn't all appear instantaneously- that could be enough to allow a pocket of normal space to exist between these things (also explaining cosmic flow) and the assymmetry of the black holes forming could explain the presence of so much matter compared to antimatter? Just an idea...
Why isn’t the absence of ‘antimatter’ explained by polarity? If we assume the early universe had a charge and matter went mostly one way and antimatter went another way, that would be consistent with our ideas of symmetry...
I could be completely wrong here but I think it's because there still exist protons and antiprotons, as well as electrons and positrons, so they wouldn't all be one charge or another, they'd be mixed. Assuming the universe is too hot early on for neutral atoms to form, the positrons would repel the protons and the electrons would repel the antiprotons, and I think gravity wins out here
@@juzoli I don't know. Maybe the other way is backwards in time- like T P speculated (It's space-time so there may be a larger structural object of space-time and we're thinking too linearly,) or maybe it's just on the other side of our light/time barrier we can't see beyond? Our space time expanded, just in a different direction-, or it didn't expand it stayed a relatively small pocket- but our imbalance positively expanded us... I am simply wondering if symmetry is important, and it seems to be, and that we don't see everything... we can extrapolate a larger structure than what we can't see... ? Have you seen the pictures of the universe that seems to mirror neural networks of a brain? Why not use another body metaphor, when a cell divides , right dna goes one way, left dna goes the other- cell divides- two objects in space separated by a thin veil.
Increasing the universes density billion-fold would just cause us to collapse back into a singularity; or whatever will replace it in a more complete theory.
@@microbuilder Should, considering Gravity's effect on Space-Time. And the greater a mass, the more measurable the distortions. Also, there would be more gravity trying to pull the accelerating matters back to each other.
Oh, this one will take a few views since I'm not a Dr. in astrophysics or any physics. 😆 I just love learning, thanks @PBS Digital Studios and everyone trying to educate us science enthusiasts.
1st Grade Teacher (c. 1989 or so): There are only 3 states of matter. Solid, Liquid, and Gas. 1st Grade Me: What about antimatter? 1st Grade Teacher: Haha! You watch too much Star Trek! That's not real. 2020 Me: Who's laughing now?
Well, antimatter isn't a _state_ of matter, it's a different _kind_ of matter. An example of a different phase state is plasma. Either way, it's sad such under-educated people can become teachers, even for the 1st-graders. Existence of antimatter was a well established and known fact long before 1989.
Liquid-crystal is a household state (LCD TVs & monitors) not oft discussed. It's one of many different states which get swept under the rug. Here's the Wikipedia Simple English page for some of them: simple.wikipedia.org/wiki/States_of_matter#Other_states Use the regular English page to see most of the rest. (IIRC a new state was proposed this year or maybe last year and I didn't see it on the page, so presumably there are others that didn't make it to the wiki.)
When I was young I thought about writing a story about a boy fell in love with an antymatter girl from parallel universe, the story ended at the moment when they tried to have a sex. I thought it was very romantic idea.
@ 3:00, when you apply CPT transformation, shouldn't you get the exact same particle (instead of it's antiparticle)? I mean charge conjunction (C transformation) gives you the antiparticle and then PT transformation brings it back to the original particle. Or I'm totally mistaken about the whole thing!
The imbalance is the direction of time. If you wind the clock back the asymmetry becomes irrelevant as the big bang singularity was infinitely dense. Antiparticles have a minutely different C.
I asked this question after taking 5-meo-dmt (God molecule) where it is legal here in Canada and got some insights into this. Obviously the first approach to this question comes from a scientific perspective, after all that's how we effectively gather data and share it with others but what if it is possible that the answer lays more in the mechanics of consciousness. What if consciousness itself is a creation source, after all everything we see around us found expression in the mind in the form of a thought before finding itself in actuality. If one shifts from a compulsive state of action to a conscious one and you get your physical body, your mind, your emotions and your fundamental life energies aligned without any negative thoughts bringing down the intensity and reverberation of the thought then it is very possible for the thought to manifest.
@@jadegecko that's not confirmed yet if you watch the video Sientists are trying to test how anti matter interact with gravity it's not confirmed if it has negative or positive gravitational effect in practice
@@jadegecko thanx for explaining. But what is the diff here? i mean if we could counter-act the gravity in one way or another - i imagine it as it would work like a touching two magnets together
Three questions 1) Could it be that one in a billion matter-antimatter collisions fail to result in their mutual annihlation leading to the imbalance in the observable universe? 2) Could dark matter have interacted with antimatter to prevent matter-antimatter collisions thereby preserving matter as we know it? 3) Could antimatter decay into dark matter? Just curious to know if these mysteries might be related.
Matt: The most expensive substance is not even printer ink.
Antimatter Printer Ink: Am I a joke to you?
Yes, but what about race stallion semen?
Making a prediction now. Antimatter Negative Mass, if it exists, is the most expensive thing you can ever produce.
Of course, since it's aniti-ink, it's price is negative.
I thought that was just a bottle of whiteout!! 😂
nice
"The only reason anything exists is because there were some particles that couldn't find a partner."
I can relate.
LOL....
Lol..
lol😭😭😭
same😞
@@darkstar4048 Finding a mate != findiog a partner.
@Astute Cingulus No, some particles didn't mate and that's why we exist
Asexuals enter the chat
Actually pretty profound. Cause isn't a partner the only reason why we exist?
Whoa whoa whoa... Have you seen the price of printer ink lately?
@@lued123 you mean scanner?
Scanner ink is so dang expensive! Even more than headlight fluid!
Did you consider toilet paper as more valuable than ink?
My anti matter printer ink annihilated by home work
@@GatorDunnAZ but not quite as expensive as elbow grease.
I really get a kick out of the goofy jokes like “not even printer ink”. Just the right kind of cheesy
ya not cheesy if it's true.
Hahah that got me too
Me too. These guys always crack me up.
Printer ink is expensive yo #2001
🤦♂️
"Not gold. Not oil. Not even printer ink."
It's toilet paper.
Toilet paper that has been printed with antigold based printer ink should be the ultimate expensive.
Could the apparent dominance of "regular matter" in the universe be just a local phenomenon? Like, it just so happens that there was more matter than anti-matter "here", and elsewhere in the universe there is a local surplus of anti-matter? Could very distant galaxies be "anti-galaxies"? Would we even be able to tell?
Nope because the universe is postulated to be isotropic.
@@tomf3150 theres decent new evidence against it
I remember an explanation that this is unlikely, as there would have to be some delineation between matter and anti-matter galaxies, and at this boundary the small number of particles drifting across would produce detectable photons. But I've been out of academia for years and the the universe is big and weird, so take my comment with a pinch of salt.
I think the rough explanation is that empty space is not empty enough to be hiding antimatter galaxies.
There's enough junk in the void that you'd be able to see some evidence of annihilations.
@@tomf3150 What does that mean? CMB radiation can be explained by small variations amplified by inflation, why wouldn't the same work for matter-antimatter proportion? It's even proposed to be a one in a billion variation, which sounds like plausible for expanded noise.
I think it's cool that confirming all our existing models and utterly wrecking them are both equally exciting.
Well said
True
Definitely not. Utterly wrecking them is way, way more exciting as it means we've found completely new things to learn about.
@@altrag idk, it's pretty exciting when you know you're missing something, but everything you test lines up with current models. So with each test you're narrowing things down and getting closer and closer to the missing piece(s). The next experiment could always be the one that changes everything even without breaking our models to pieces.
"Annihilation partner" will be the name of my punk rock band
I would definitely listen to that.
Punk died long time ago
Punk rock cowboy?
"Charged conjugation" will be my DJ name
Babe, are you my annihilation partner? Because when we come together it's pure energy.
5000 years from now, mankind has mastered the universe and generates free energy by altering the laws of physics in an area at will, we are capable of traversing galaxies in seconds, and we can instantly fabricate anything from thin air with a mere thought.
Somehow, nobody can afford printer ink, still.
Zero point energy ain’t that simple, I’m afraid it’s not gonna be cheap either.
5000 years from now, mankind destrod itself probably.
@@gert-janbonnema Mankind is better than that.
5000 years from now on is too small for that bro,maybe 5-50 million years if we survive till then, besides some thing's which you are mentioning aren't possible by the current laws of universe as we know now so .....
@@Anonymous-sp1zk 'Twas a joke.
For those who are wondering where antimatter actually IS:
It’s the ink inside printer cartridges. That’s why when it meets your printer, it annihilates itself, and reads empty, despite you JUST buying it.
0:33 If we're going to call the antimatter electron a "positron", why aren't we calling the antimatter proton a "negatron"?
Wouldn't it be a "negaton"?
You could, but then Megatron might show up unannounced. That's not something you want to risk.
A negatron is just the proper name of the electron.
@@JayVal90 You mean _was._
Or conton
"You can't be made of antimatter because obviously you matter very very much"
Nice cheesy pickup line 🤣
Your fired
@@SF-tb4kb bro wtf is your prob lmao
@@SF-tb4kb you are not cool. YOU.
Not being able to find an annihilation partner to smash with. Story of my life.
back in the days nobody wanted me on their soccer team either. And now not even the universe wants me to reach Nirwana anymore... damn :-)
/shrug smashing is overrated anyway. I quit doing that 15 years ago, a few minutes of fun isn't worth many months of drama.
@@fvckyoutubescensorshipandt2718 what do you mean
😂😂😂 find a girl that isn’t like this dudes past experience, they’re out there
Virgin Baryon: has mass because his existence is heavy, experiences time as an arrow
Chad Photon: already annihilated, chilling at the speed of light in an eternal present, only experiences time moving forward when he interacts with something
"Does Antimatter Explain Why There's Something Rather Than Nothing?"
No, antimatter anti-explains why there's something rather than nothing.
Well yes, but actually yes.
Well that discussion got anihilated quickly.
What I'm essentially getting from this is: "If it weren't for an imbalance of matter & antimatter, there wouldn't have been enough matter to have formed the universe that birthed us. Matter-antimatter annihilation releases photons. There are a billion times more photons than matter particles. If the antimatter-matter distribution had been symmetrical then that number would be far far greater, such that the chance that matter particles would encounter each other would be nearly impossible except for in small isolated groups without the gravitational pull to form stars or planetary systems. As the universe expands & cools down, the chances become even less. A perfect imbalance of antimatter allowed us to exist. The entire universe is a lucky Goldilocks Zone. Not just on Earth. If the multiverse theorem is correct, then this is just one version of an infinite number of universe possibilities where only a limited number are capable of forming & supporting life in whatever form it may be.". Any major misunderstandings?
But the problem is far worse than an insufficient imbalance to explain the rise of the observable universe. Rather it is this: Why is there any imbalance between matter and antimatter at all? Anti-matter should exist in a quality precisely equal to that of matter, unless they are not perfect mirror-images. So far, though, even to a high degree of precision, they are perfect mirror images. There is a solution but it is theoretical: all violations of charge-parity symmetry are offset by violations of time symmetry (i.e., causation does not run exactly the same in reverse, as seen in experiments involving kaons), and if the offset between the two symmetry violations (CP on the one hand, T on the other) may itself be viewed as a symmetry (i.e., CPT symmetry). This solution has been around for decades , but it seems contrary to traditional physics, right up through the Theory of Relativity and its notion of space-time, which recognizes no asymmetry in time. But if we could find a way in which matter and antimatter were not mirror images, the whole problem would seem soluble. So far, though, no such luck.
@@Primitarian I'd like to know why the possibility that there was simply more regular matter created than antimatter in the first place is off the table. Idk enough about this stuff
@@Primitarian
I have a theory that can explain why matter and anti matter are exact opposites, but,
it requires a different way of thinking.
what's going on is beyond us all and may never be proven,
When you consider how big the universe is, and how much space you do need to be able to give the universe a place somewhere as existence (matter)
but there is actually no possibility at all to create a universe (matter),
then you have to assume that the opposite is necessary to give matter (the universe) a place as existence
If there is the possibility to create a universe (matter), while there is no need for space thanks to anti-matter,
the possibilities are endless as currently the universe is still expanding from the big bang,
thus, anti-matter is still present in the same amount as matter to give the universe (matter) an existence in an anti-material enclosure.
"Not even printer ink", Oof that's a bold statement lol
I don't believe antimatter is more expensive
@@BigyetiTechnologies yes but it is less valuable than anti printer ink(antimatter verson of ink)
Stop giving printer makers ideas!
Re: baryon asymmerty: suppose the universe is either infinite or at least 10^large times larger than the observable part. Could it be that we just live in a sector that was randomly antimatter-poor because 10^large particles and their 10^large antiparticles probably won't have identical average momenta? So all the antimatter is just literally outside of our cosmic horizon? Could it be that, like our distant descendants who won't be able to see galaxies or the CMB, we just don't have access to observations that could solve problems like this?
We usually assume the universe is Isotropic.
I argued about that some time ago and my answer is: No, since our observable universe is isotropic in a large volume. Our existence in a local patch of 'regular' matter would not require that: A far smaller volume of relatively isotropic 'matter' could allow for our existence. Assuming the distribution is like that by chance, the probability of a patch of 'regular' matter with a volume < 1 GLy³ would be extremely much more likely to be where we find ourselves than a patch of isotropic 'regular' matter of the size of our observable universe with thousands of GLy³.
@@roblaquiere8220
Isotropic on large scales. The earth's mantle and the near void of space of very different, cubic meter for cubic meter. Galaxies and galaxy voids are equally different, 100-cubic light year to 100-cubic light year, and the observable universe is only about 9*10^10 light years across. If this discrepancy only presents itself at scales similar to 10^100 light years, would only being seeing .0000000000000000000000000000000000000000000000000000000000000000000000000000000000001 times thescale necessary to detect this anisotropy.
Just saying.
@@kindlin It'd be very unlikely that we'd exist in such a large patch though, smaller patch much more likely. The fact our patch is so big suggests that the universe is isotropic at large scales.
@@kindlinTo produce a local overabundance of at least ~10^80 matter particles (in the observable universe) by chance, the original number of particles and antiparticles would have had to be around 10^160. This is impossible because 1. the energy released by their annihilation would be far higher than we observe, and 2. annihilation must have ended by about one second after the Big Bang, at which time the observable universe was far too small to contain that many particles (it would correspond to about a million particles per Planck volume).
"ALPHA uses CERN'S proton synchotron to get their anti-protons; The synchotron accelerates protons to 10s to 100s of giga electron Volts of kinetic energy, corresponding to over 99% of the speed of light" is the most amazing sentence I've ever heard on any UA-cam video ever. It sounds like the most crazy ridiculous scifi nonsense ever, but it's COMPLETELY REAL
anti protons are notanti matter, anti protonds are just as simple as the opposite poles of a freaking magnet.... and dont be so fond of the 99% of speed of light at cern, it is nothing compared to the 99% of speed of light, in those regions of the universe that are vastly empty... observing the speed of light on earth cpmpared to speed of light there , is as if watching a microbe racing vs a formula 1car.
@@AbyNeon What are you even saying
@@AbyNeon Like, literally, you just spewed an entire paragraph of nonsense
@@DrakiniteOfficial Thats becuase You do not know what I do know.
@@AbyNeon God you must be fun at parties. First of all antiproton is an anti-particle, and the fact that speed of light in vacuum is way more doesn't change the fact that reaching 99 percent speed of light here on Earth is absolutely insane and dont get so "fond" of your knowledge there are people out there(mostly in this comment section) who would make you feel as smart as a bag of sand. If its about comparison so much then relatively youre a fkn donkey mate.
Anti-matter: "So..."
Matter: "So what?"
Anti-Matter: "ARE WE NOT GOING TO EXPLAIN THE ELEPHANT IN THE ROOM?"
Matter: "What, I don't see anything?"
Anti-Matter: "ITS LITERALLY THE BIGGEST THING HERE!!"
Dark Matter: "Who, me?"
What about the Dark Anti-Matter? Or is it Anti Dark-Matter?
@@imadetheuniverse4fun
Anti-dark matter is just white matter, duh
@@moahammad1mohammad Negatively wrong.
@@moahammad1mohammad wrong
1:40 an annihilation partner - I'm going to use this to describe my toxic relationships to my therapist.
Rip
please do an episode about the proton spin crisis that is still unresolved to this day
I want to see an episode on the size limit of black holes.
@@r2dxhate I'd love to see an episode about some fractal theory tbh
I'm excited about the rumblings about axions participating in baryogenesis, especially now that we're seeing what could be evidence of solar axions.
I've not heard about any detentions.. what dya know?
Can you explain in your comment as you would to someone not from the field, please? Sounds interesting!
@@vitorfalcao5969 There is an episode in this series about Axions which were porposed as a solution for the strong CP problem as a consequence of Peccei-Quinn mechanism. Check out the episode so you'll understand how it is relevant.
@Astute Cingulus There has been recent evidence for possible Axion detections the issue is we can rule out minute traces of Tritium contamination and radioactive decay and the detections are still only just over 3 sigma
I wrote a scientific paper on antimatter, but my anti-dog ate it.
Then the paper and the dog were anhialated when my containment field collapsed due to an unpayable electric bill.
There were no survivors.
No survivors anywhere on the planet, I should think. Where was this exactly?
@@esquilax5563 Actually no, an average dog would release enough energy to power norway for a bit over 2 years if it combined with the same mass of antimatter. It will uld make a sizable explosion but we wouldn't all die.
If only it were an anti-electricity bill. They would then have to pay you. LOL
Matt, would you mind going deeper on why CPT transformation changes a particle into its anti particle. On the surface it would appear that would result in the same particle, since C transformation would flip the sign. And then T transformation would flip the sign once again, since a positive particle moving forward in time should behave just like a negative particle moving backwards in time.
An episode on WHY and HOW matter and antimatter annihilate would be nice.
I had no clue we haven't already tested how antihydrogen behaves in a gravitational field. It is absolutely bonkers that we don't know yet and I'm super excited to find out whether or not they go up.
It's obviously going to fall down because reality sucks.. But... If it doesn't...
I hope it goes up.
@@volkhen0 duh. But then again, I really hoped that experiment to test for higher spatial dimensions would turn up a number higher than 3 but that didn't turn out either
The problem is antiprotons can be confined with electric & magnetic fields. Antihydrogen on the other hand...
Space-Time tells antimatter how to travel.
But how does antimatter tell Space-time to bend?
Kudos to you for explaining CPT violation in an understandable way, and why it's important
Imagine seeing a copy of yourself walking backwards through the door, turning around and looking at you, and standing in front of you with its back to you.... knowing your fate is to stand up and walk into your copy... at which point you start to experience time backwards.
I tought that ideia would lead to an awesome music video!
_Dr. Manhattan has entered the chat._
There's a scene in this one book (a parody of another one but teaching quantum mechanics) in which the character is walking forward, sees two copies of him/herself appear, collides with and becomes one, goes back in time while still walking forward, and then collides with and becomes the other.
If you experienced times backwards, wouldn’t your memories be the other way around as well.
You would un-remember.
@@Ethan-cz8xq damn thats so mind bending that It gave me brain damage
I'm in the middle of a Star Trek:Enterprise binge , and this talk of antimatter is "like, yeah bro, tell me something new, now let me get back to adjusting those antimatter injectors", but I never knew that antimatter containment of anything more than microseconds was actually a real thing. Thanks for another great video.
I love how you casually just go as deep as you can on any subject. Thank you.
Off topic
Do you ever have any outtakes?
A semi annual video of them would be nice to see.
It might look, a little like this... ua-cam.com/video/2un9rO2ZF4g/v-deo.html
@@technocore1591 I would pay good money if his pants look anything like that!!
Techno Core Hugh Laurie is such a talented actor, didn’t even recognize him at first! What a wonderfully funny sketch, thanks for posting link.
John Early not at all! Stephen Fry is also brilliant and you should definitely check out their old sketch comedy show A Bit of Fry & Laurie.
Matt, great job on this episode. I really liked the background along with showing the current experiments that are in the works to test the theorys!
2:50 I thought CPT sends particles to particles whereas C by itself sends particles to anti-particles.
Yeah this is a surprising conceptual mistake in the video. CPT is the identity operator by the CPT theorem. T sends particles to their CP conjugate so CPT=CP(CP)^{-1}=I. You also do not need CPT violation for matter-antimatter asymmetry. Many physicists today think that maximal CP violation in the neutrino sector is quite likely to allow for a process known as leptogenesis whereby CP violation in neutrinos combined with a strong first order phase transition sometime around when the universe cooled from the plank scale to the electroweak scale allowed an excess of matter to be generated via B+L number violating processes like sphalerons.
I think a better explanation for this video would be something like the following: You can think of C, P and T as the sides of a triangle where the vertices correspond to the different states you can get by starting from a chosen state and applying C, P or T. This works because C, P and T are all their own inverses, ie C^2=P^2=T^2=I and they commute with each other. For example, CPC=CCP=C^2P=IP=P. The CPT theorem is a proof that in any locally Lorentz invariant unitary quantum field theory the triangle must be closed, ie CPT=I. If there was CPT violation (meaning CPT!=I) then CPT wouldn't quite take a state back to where it started which can only happen if you violate local Lorentz invariance, unitarity (you can think of this as probability conservation, meaning the sum of probabilities for all possible outcomes of an experiment should be 1) or both.
@@patrickbryant_ that sounds oddly like group theory!
Sunshine Daniela yup! I’m a big fan of both finite and Lie groups and their applications to physics :) I highly recommend Peter Woit’s text book “Quantum Theory, Groups and Representations”
@@patrickbryant_ I wonder if PBS SpaceTime it´s going to see your comment, or if they are going to make any corrections in a future video
One interesting fictional take on antimatter is in Greg Egan's Orthogonal trilogy. Matter that's been round the universe and odd number of times (relative to you) ends up as antimatter. You can, however, safely interact with it if you get your state of motion such that your arrow of time points in the opposite direction to it. Actually, the whole universe of that trilogy is just fascinating, and Egan spends at least as much time on the characters discovering the physics of their universe as whatever human-like conflicts they have with each other.
been watching you for years. just spent 15mins finding out what your name is and where you worked. maybe i can get an autograph whenever i visit new york some day. you've been putting me to sleep for years but not in a bad way. you're always the last thing i watch before going to bed as my mind wonders about your lectures. thanks Matt for all you do
If anti-matter can be "viewed" as matter moving the opposite direction in time, then why can't the asymmetry of matter and anti-matter after the big bang, be explained by the anti-matter just going the opposite direction in the time dimension?
If a matter universe is created in the positive time dimension (ours), then an anti-matter universe should be created in the opposite time dimension.
@@flakmagnet9357 I suppose that would be impossible to know then. Because even if it was true and we managed to create a time machine we would never be able to go further back then the Big Bang and come back to tell the tale (if for no orther reason, because we would found ourselves made of matter in a universe of anti-matter and would probably be annihilated pretty quickly). At least that's how I see it.
@@nate7790 or would you? The big bang theory is in serious trouble anyway.
. . . Or even in some other dimension?
The "T" reflection is for laws of physics, the particles don't literally go back in time (at least we think; not much research has been done on antimatter).
I'm rooting for anti-matter to have anti-gravity. I posited it decades ago when I was in college as a solution to the problem of why there were not equal amounts of matter and anti-matter observable in the universe. Anti-gravity would cause anti-matter to segregate itself from matter into discrete clusters, even to the extent of discrete clusters of galaxies. Ironically, I scrapped the idea because it seemed to me that the net repulsive gravitational force would lead to the acceleration of universal expansion, which was not even considered possible at that time.
Interesting
Anti-gravity with respect to what? You mean that interacts with anti gravity with matter?
that's not how it works . anti-matter produces the same gravity as regular matter
@@NitpickingNerd That's not actually true experimentally. We have only produced tiny amounts of anti matter and we cannot measure how they gravitate.
From the theoretical standpoint there is no reason at all for antimatter to behave gravitationally in a different way than matter I agreed with that, but you cannot say that as a true fact because we haven't seen masses of antimatter large enough to test gravity with antimatter.
There is the big bang theory though which is extremely precise in some of its predictions and it assumes antimatter gravitates in the same way as matter does. Antimatter gravitating differently would produce peculiar signatures in cosmological observations and we haven't observed them, so yeah from this point of view you can say that we know experimentally that antimatter gravitates normally
How can something with anti-gravity cluster? Should it not rather be shattering evenly over the whole universe?
I love watching tyrion lannister's taller smarter cousin talk space-time
"A Lannister always pays his debts" is just a metaphor for Newton's 3rd law.
“ I drink and I know things.” - electron
Thanks to the speaker for slowing down in this episode. I have loved the information in these episodes but the speaker was so fast that I could not understand much. Loving this now
Using the LCH to make antimatter is the most roundabout method I can think of, why not use a basic gamma ray laser that can be made with any laser and some magnets, if you want a specific antiparticle, just change the frequency of the laser.
Why does matter and antimatter annihilate each other? Apart from "because the mathematics say so", is it possible to give a more intutivie explanation for the phenomenon?
It's not just math, home.cern/news/press-release/cern/first-atoms-antimatter-produced-cern
I struggle to find a real intuitive answer to that question, and what you find intuitive.
An analogy would be 2 substances, that when put together will react and explode.
Also don't think that they disappear if they come together, but "explode" transforming into radiation.
At least that's my understanding of it.
But I'm no physicist, so don't listen to me :-P
The way I understand it is that particles are made of quarks. You focus on the particles and not the quarks, that is why it's not intuitive.
no expert here but i guess its similar to destructive interference between waves.
The process of creation is a little more intuitive. Energy can take many forms and one of those forms is matter, as Einstein showed. Therefore, when there is a lot of energy left over, matter can spontaneously appear.
Because however, certain properties such as charge are conserved in space, whenever a positively charged particle appears, a negatively charged particle must also appear to compensate. This would be our antimatter.
Whatever happens at annihilation, is the exact opposite and reversed process of this creation. I have not really studied Quantum Field Theory yet, so I do not know the math. Maybe someone else can give a better explanation of what is going on under the hood.
It's about as deep as asking why matter exists. I can't think of a more fundamental way than the laws we make for real matter predict it and we observe it.
A little more insight is that in classical laws concerning mass, i.e relativity and general relativity, the laws behave differently for a negative mass/energy and so there are axioms to say this cannot happen. Reasonably so as otherwise there would be some crazy objects running.
Now you may know E =mc^2 but it is actually an at rest equation. The true one is E=sqrt((mc^2)^2+(pc)^2). That's funny because from high school you know a square root has plus and minus.
This is going to be mathsy, but remember the maths is self consistent and relates to a physical thing. Of theorists do there jobs right and nothing is shown to counter it and the result is observed, its physics. Maths is logic but hard to understand and easy to do.
SO the time dependent schrodinger equation is non relativistic. Look it up for its form. But the time derivative relates to energy, the space derivative to momentum (E=p^2/2m=0.5mv^2). If you plug the same ideas into the Special relativity equation above you, after some work you get the Dirac equation
(Klein gordon did it with a second order time derivative (E^2) but that was all sorts of wacky, things affect you outside the light cone and if p->0 it did not resemble the schrodinger equation as it should at low speed/momentum).
The Dirac equation. Look it up. Works very well, but still has negative energy solutions. However when you plug these solutions into the equation and include spin (or chirality [spine parallel to the direction of motion] more generally) the negative energy solution behaves as a positive one with opposite spin/chirality and charge.
So in quantum mechanics our negative energy solutions are in fact objects with opposite quantum numbers that behave with positive energy *but* are still distinct from the normal matter states.
Here is when it's a bit beyond me.
Dirac thought of this that a vaccuum is in fact relative and there is an infinity sea of lower energy, or negative energy, particles below. When a particle is created it is excited from this lower state. The empty lower state is the anti particle (why they come in pairs) and has opposite quantum numbers. I don't know why they behave like normal mass.
The *real* modern interpretation is in QFT, sorry but I do this course next semester and will get back to you.
"Animatter may experience antigravity" - all I heard was "Scientists are testing for hoverboards" GO you beautiful nerds GO !
Haha using antimatter for hoverboards would be ridiculously irresponsible. The better use would be as negative mass for warp drives. That way towns won't disappear off the map after every hoverboard accident
@@gerardt3284 this is exactly how I thought it might be used
@@gerardt3284 Maybe you have a point, I crashed my mountain bike on the weekend into a tree, it was nice that I didn't obliterate myself and Tewantin.
If you say so... But your overboard would explode the instant you get it out of it's package.
Just compress the regular Helium/Hydrogen from a weather balloon into your Hoverboard and you're good to go.. :>
Wow that was interesting! It’s amazing what mankind has achieved. Those CERN experiments are so fascinating. Thanks for translating that research into human language, Matt 👍🏻
Amazing. Looking at all that gear makes me want to congratulate the engineers. Such complexity. Makes my engineering look like playschool stuff.
Wow, Matt! An episode of PBS Space Time that I feel I fully comprehended!
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.
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"In a wee bit after the beginning, G-d said, 'Let the number of positrons be one less than the number of electrons', and, lo, it was good, really, quite good"
Best comment section ever, I just laughed more than I can remember doing in a very long time
Matt: Could the difference in mater to antimatter be linked to the curvature of spacetime? If quantum fields arise from some microscopic topology of spacetime they would have "width" like a soap bubble on the surface of water. If the universe were to have positive curvature the "inside" width would have slightly less volume than the "outside" width especially closer to the big bang when the curvature was greater. So if anti/mater particles form on opposite sides of the spacetime sheet, particle generation might be biased towards the side with greater volume while still preserving the chirality of all particles. Maybe the disparity between mater and antimatter is proof that the large scale curvature of the universe is not flat. Who knows, just the rantings of an armchair quantum physicist.
Are you an actual quantum physicist? This idea seems so elegant I hope it's true. Two super nice and symetrical ideas (a sphere and waves of curvature in opposite directions) combining to make the asymmetry we see in our universe. I imagine you might actually be able to calculate how small or large the curvature would have to be for this idea to work
Actually, I just did the calculation on this assuming the universe is a 4-spherical shell embedded in 5 dimensions, as well as another assuming it's a 4-cylinder shell (infinite in time). Assume the particles (topological deformities) have a small width, say t. For the proportion of matter to antimatter to be off by one in a billion, the radius of the universe would have to be only 3 to 4 billion times the width, t. That's not nearly large enough to account for measurements that show the universe is demonstrably flat up to our measurement capacity. The universe is more than 40 billion lightyears in radius, so t would need to be about 10 lightyears, which is ludicrous. So my back of the envelope mathematical understanding says this theory is probably not correct. But I really am no physicist - just doing the math
2:55 I think you meant that if you apply a CPT transformation to a particle you get itself. For example, if you do just a CP transformation on an electron, you get a positron spinning the opposite way and moving in the opposite direction. Apply a time-reversal transfomation to this and you essentially get the same electron you started with. For another example, if you do a PT transformation on a proton, you get an antiproton going in the same direction and spinning the same way as you started. Flip the charge ans you get the proton you started with.
Thank you, I thought I was dumb
The question of why there is something rather than nothing is one of the most profound in cosmology and philosophy. Antimatter, the counterpart to ordinary matter, has been proposed as a potential key to understanding this mystery, but the answers remain speculative and complex.
In the context of the universe's origins, the current leading theory is that the Big Bang initiated the expansion of the universe from a singularity, a point of infinite density and temperature. During this event, equal amounts of matter and antimatter were created. However, when matter and antimatter meet, they annihilate each other, producing energy in the form of photons. If the universe began with equal amounts of matter and antimatter, we would expect complete annihilation, leaving behind only radiation, with no matter to form galaxies, stars, or life.
The fact that the observable universe is overwhelmingly composed of matter and not antimatter suggests that there was a slight asymmetry-known as **CP violation** (violation of charge conjugation and parity symmetry)-in the laws of physics that favored matter over antimatter. This asymmetry may have allowed for a tiny excess of matter to survive after most of the matter and antimatter annihilated each other. The exact mechanism behind this matter-antimatter imbalance is still one of the greatest unsolved mysteries in physics.
Now, can antimatter help explain why there is something rather than nothing? One hypothesis is that the presence of matter, rather than complete annihilation, points to unknown physical processes or forces at play during the early moments of the universe. The existence of antimatter and its interactions with matter could be a clue to deeper symmetries or properties of the universe that we have yet to uncover. For instance, some theories suggest that the existence of antimatter might indicate that there is a hidden universe of antimatter that mirrors our own, existing in a way that is not immediately detectable due to our own matter-dominated environment.
Moreover, questions about why the universe exists at all can lead into even more speculative realms of physics, such as multiverse theories, where our universe is one of many, each governed by different physical laws and conditions. In such scenarios, the laws of physics in our universe might be uniquely suited to allow for a matter-dominated cosmos.
In conclusion, while antimatter provides insight into the asymmetry between matter and antimatter, it does not alone answer the profound question of why there is something rather than nothing. The imbalance may be a crucial part of the puzzle, but it is likely that a complete explanation will require advances in our understanding of fundamental physics, including quantum field theory, particle physics, and cosmology. It may even point toward entirely new theories that merge the macroscopic and quantum realms, seeking to answer not just why the universe has the properties it does, but why it exists at all.
This is just the most awesome show on the internet.
Is there any measure confirming the whole one in a billion chance of matter to "survive" annihilation with anti-matter? To me it always sounded like random pre-inflation variations in matter-antimatter proportions should be able to explain the difference. Has it been ruled out or is it just that physicists don't like that option?
Time and time again, I must say, your wife's art saved the channel.
If matter and CPT shifted matter annihilate, what happens if matter and semi-shifted matter interact? Do they partially annihilate? What is left over if they do? Or what is made if they don't?
At a very small scale, they either have decayed or not. The rate of decay is predictable on a large scale, but at the individual atom level it is not, and rather has a probability of decaying or not at any given point in time.
As such there is no such thing as "partial decay" unless you are talking about large atoms decaying into multiple smaller atoms.
@@elinope4745 is matter-antimatter annihilation decay though? I though decay was spontaneous and random, not the interaction between two distinct atoms
The CPT symmetries are though experiments rather than actual physical processes that can happen to a particle, so it doesn't make sense to ask what would happen if a particle was semi-shifted.
There are no semi-shifted particles, that's the point of CPT symmetry.
Spacetime is the only popular science outlet I trust to always tell the whole truth
I admire the presenter, he's contractually obliged to re hash the old concepts of cosmology. And he does well.
Perfect timing, posted as I was sitting down to eat...
What are you eating? I am just having coffee with a bun.
Just some stew.
SpaceCakeism Stoofvlees, it’s a stew
Haha same, hello fellow Dutch. Wokschotel here ;-)
Edit... Or Flemish!
Man I hope it goes up in the experiment. How exciting would that be!
In a 1960s Star Trek episode, the "Doomsday Machine" used a pure antiproton beam to destroy planets.
This series and the final phrase of each episode make it increasingly clear that EVERYTHING IS JUST SPACETIME.
I do have a question about this problem, if the mass of the particle and antiparticle are equal, but the charges are opposite, could this be solved by the different spin, meaning if they started out moving in a similar direction, could a weak change the left handed one into something else, causing a cascade effect where only antiparticles where left-handed in their pairs, effectively transmuting antimatter into matter of a different charge?
Old joke (from 2012 when LHC was launched): "Particle scientists love to make meetings every 10 to 20 billion years and launch some powerful particle accelerator..."
Field trip to physics lab: "everyone grab your annihilation partner...!"
Right lads, I'm about to become a world-leading expert on anti-matter. See you in fifteen minutes
BOOM !
One of the most fascinating episodes yet. The upside down's demogorgon is offended that you said its CPT was violated
I genuinely believe the best thing about the PBS videos is the comments section, & people copy & pasting from lesser known texts pretending to know what they're on about. It's great. Maybe though, we should just accept that 99% of us don't actually understand are just attempting to educate ourselves.
Thought experiment I can't figure out the answer to: if a black hole made of matter somehow collides with a black hole made of antimatter, would they annihilate? Or would they merge into a bigger black hole as normal because only the mass matters? If they do annihilate, would that create a Kugelblitz because all the particles inside are now photons? Or would the photons created violently rip the system apart, overcoming gravity?
Interesting
Whatever happens it cannot escape the event horizon, so from outside it would remain just a normal merged black hole. Inside? We don't even know if matter exist or if even something exist inside a black hole normally
@@WaveOfDestiny This is a black hole in the midst of colliding , so if I'm not mistaken the event horizons would kind of stretch out until finally they merged, perhaps leaving a short time that light could escape and be measurable? Or is the process of merging continuous such that the two event horizons meld into each other without ever shedding any matter?
"Why not test it?" 5 million dollars would like to have a word with you
If high enough energies can make a random bunch of particles (like in the LHC), can't the matter-antimatter imbalance be the result of probability? They could both have the same probability to be made, but we ended up with more matter by chance.
My bet, CPT symmetry holds but antimatter and matter are not related by a CPT transformation, you also have to invert the mass. Contrary to the common belief, a particle with negative mass would not "fall" upwards in the presence of a dominant positive mass gravitation field such as the Earth. The geodesics of spacetime are the same. The difference is that the Earth would at the same time be repelled by the negative mass, but if that mass is on the order of a proton, compared to the Earth, the only effect would be that it would appear to fall slightly slower, which is actually supported by the latest evidence. Antimatter having negative mass means that it would repel other antimatter and thus could not condense into stars, galaxies and whatnot. Rather it would spread out into a diffuse fluid, and form halos around clusters of positive matter. This asymmetry explains why the universe *appears* to have more matter than antimatter, while also going a long way to explaining dark matter and possibly even dark energy. Not my idea, there is a great paper all about it.
A little delayed here but I have a question. If the Andromeda galaxy were made of antimatter, would we be able to know it? I guess it boils down to, does antimatter give off a different kind of photon than normal matter. Just curious. Thanks.
I am so pleased that such difficult science is presented in a manner that most everyone can at least appreciate. Carry on!
When you said CP Violation, i thought of the Half Life 2 Level lol
Wouldn't they travel the other direction through time, so they would be on the other side of the big bang? Ex. My anti-counterpart would exist 26 billion years in the past.
Extending time "through" the big bang is problematic at best, and utterly absurd at worst.
On the other hand, if you take time as an imaginary axis, the euclidean metric actually lines up with the spacetime interval. Since i and -i are algebraically indistinguishable, that would make the behavioral symmetry of antimatter quite obvious. If you take the big bang as the origin event of this 3real+1imaginary spacetime, all the antimatter lives "below" space in the negative imaginary axis.
Probably wrong, but it's a pretty thought, at the very least.
Fiddlewinks anti matter doesn’t “literally” move backwards in time
Antimatter particles moving backward in time is more of a description of what the laws of motion for antiparticles are rather than it is an actual declaration that they somehow violate causality and truly travel backward in time.
@@Nosirrbro Check out Andrei Sakharov's model of Cosmology, where the arrow of time is reversed before the Big Bang.
en.wikipedia.org/wiki/Andrei_Sakharov#Particle_physics_and_cosmology
@@fortuna19 It's motion is opposite relative to ours. Why are we moving "forward" through time? For every direction you travel, you are also traveling the opposite direction but with a negative sign. Moving 20 km north is the same as traveling -20 km south.
One of my favorite episodes so far. And I've seen them all!
Finally an episode that I could follow and understand :)
Would a universe made of anti mater . be the same as. Our university and our matter would be the anti matter
There would likely a larger number of unstable isotopes as well as a decrease in half life of some current unstable isotopes.
That’s what CPT symmetry postulates and that’s what the current belief is, yes.
Osmosis Jones If CPT symmetry is beoken, then no!
I literally audibly exclaimed when he mentioned we can make stable atoms of anti-hydrogen that last DAYS. I would have been impressed if they lasted half a minute! It's amazing the kinds of extreme science we're able to do right here on Earth! Really excited to see what results ELENA finds!
"You called my abuelita...biznatch?"
Better Call Saul is such an underrated show... the last few seasons are god tier. It's Breaking Bad all over again. The show is getting better every season.
Yeah I'm gonna have to send you to Belize
I always had this crazy idea that the universe could be infinite. The rebuff to this was that an infinite universe would be unbearably hot because eventually it would fill up with photons. Then I realised that would just make a whole stack of koogleblitz(?) Black holes and they wouldn't all appear instantaneously- that could be enough to allow a pocket of normal space to exist between these things (also explaining cosmic flow) and the assymmetry of the black holes forming could explain the presence of so much matter compared to antimatter? Just an idea...
This channel is one of the best things that happened to Physics ♥️
Second best, printer ink is better
Lol
Josh Duggar knows a thing or two about CP violations…
Why isn’t the absence of ‘antimatter’ explained by polarity? If we assume the early universe had a charge and matter went mostly one way and antimatter went another way, that would be consistent with our ideas of symmetry...
I could be completely wrong here but I think it's because there still exist protons and antiprotons, as well as electrons and positrons, so they wouldn't all be one charge or another, they'd be mixed. Assuming the universe is too hot early on for neutral atoms to form, the positrons would repel the protons and the electrons would repel the antiprotons, and I think gravity wins out here
You can have antineutron...
John Ege And where is this “other way”, and why don’t we see it?
@@juzoli I don't know. Maybe the other way is backwards in time- like T P speculated (It's space-time so there may be a larger structural object of space-time and we're thinking too linearly,) or maybe it's just on the other side of our light/time barrier we can't see beyond? Our space time expanded, just in a different direction-, or it didn't expand it stayed a relatively small pocket- but our imbalance positively expanded us... I am simply wondering if symmetry is important, and it seems to be, and that we don't see everything... we can extrapolate a larger structure than what we can't see... ? Have you seen the pictures of the universe that seems to mirror neural networks of a brain? Why not use another body metaphor, when a cell divides , right dna goes one way, left dna goes the other- cell divides- two objects in space separated by a thin veil.
If antimatter is T symmetric then is there an antimatter Big Bang in the far future moving backwards towards us?
@PBS Space Time that background is "gold" 👌
Cool shoutout - Antimatter cake. Sounds delightfully devious Seymour.
"don't need an entire gram... Just a handful of particles are enough..."
Umm... 🤔 😂 🤣
Interesting to think what the universe would be like if there had not been anti-matter to annihilate all the regular matter.
A bit crowded?
@@edtheduck6219 Yeah I was thinking lots of black holes. I also wonder if the expansion of space would be slower due to the higher amount of matter.
Increasing the universes density billion-fold would just cause us to collapse back into a singularity; or whatever will replace it in a more complete theory.
@@microbuilder
Should, considering Gravity's effect on Space-Time. And the greater a mass, the more measurable the distortions.
Also, there would be more gravity trying to pull the accelerating matters back to each other.
@@microbuilder does the annihilation of matter cause energy to be destroyed?
Finally people are getting what Ive been saying about "darkness/nothing" for about a decade.
Oh, this one will take a few views since I'm not a Dr. in astrophysics or any physics. 😆 I just love learning, thanks @PBS Digital Studios and everyone trying to educate us science enthusiasts.
Ahhh he said CP violation
Nice reference, Kelly Bailey!
We all know 'that couple'... you get them together, and the whole party blows up.
1st Grade Teacher (c. 1989 or so): There are only 3 states of matter. Solid, Liquid, and Gas.
1st Grade Me: What about antimatter?
1st Grade Teacher: Haha! You watch too much Star Trek! That's not real.
2020 Me: Who's laughing now?
Well, antimatter isn't a _state_ of matter, it's a different _kind_ of matter. An example of a different phase state is plasma. Either way, it's sad such under-educated people can become teachers, even for the 1st-graders. Existence of antimatter was a well established and known fact long before 1989.
Liquid-crystal is a household state (LCD TVs & monitors) not oft discussed. It's one of many different states which get swept under the rug. Here's the Wikipedia Simple English page for some of them: simple.wikipedia.org/wiki/States_of_matter#Other_states
Use the regular English page to see most of the rest. (IIRC a new state was proposed this year or maybe last year and I didn't see it on the page, so presumably there are others that didn't make it to the wiki.)
When I was young I thought about writing a story about a boy fell in love with an antymatter girl from parallel universe, the story ended at the moment when they tried to have a sex. I thought it was very romantic idea.
Much romatic
@ 3:00, when you apply CPT transformation, shouldn't you get the exact same particle (instead of it's antiparticle)? I mean charge conjunction (C transformation) gives you the antiparticle and then PT transformation brings it back to the original particle. Or I'm totally mistaken about the whole thing!
The imbalance is the direction of time. If you wind the clock back the asymmetry becomes irrelevant as the big bang singularity was infinitely dense. Antiparticles have a minutely different C.
"Where is all the anti-matter?"
Lemme counter that question with another question.... "what has it gots in its pockets?"
That was a riddle not a question.
I asked this question after taking 5-meo-dmt (God molecule) where it is legal here in Canada and got some insights into this. Obviously the first approach to this question comes from a scientific perspective, after all that's how we effectively gather data and share it with others but what if it is possible that the answer lays more in the mechanics of consciousness. What if consciousness itself is a creation source, after all everything we see around us found expression in the mind in the form of a thought before finding itself in actuality. If one shifts from a compulsive state of action to a conscious one and you get your physical body, your mind, your emotions and your fundamental life energies aligned without any negative thoughts bringing down the intensity and reverberation of the thought then it is very possible for the thought to manifest.
imagin if anti matter is repelled by gravity our understanding of the universe would be flipped upside down
that would mean warp drives, right? :) looking forward to the results
That'd be negative matter, not antimatter. Antimatter just has opposite charge, not opposite reaction to gravity.
@@jadegecko that's not confirmed yet if you watch the video Sientists are trying to test how anti matter interact with gravity it's not confirmed if it has negative or positive gravitational effect in practice
@@jadegecko thanx for explaining. But what is the diff here? i mean if we could counter-act the gravity in one way or another - i imagine it as it would work like a touching two magnets together
Maybe it's Aunt and Uncle sent Antimatter to live in Bel Air..
Three questions
1) Could it be that one in a billion matter-antimatter collisions fail to result in their mutual annihlation leading to the imbalance in the observable universe?
2) Could dark matter have interacted with antimatter to prevent matter-antimatter collisions thereby preserving matter as we know it?
3) Could antimatter decay into dark matter?
Just curious to know if these mysteries might be related.
I greatly enjoy hearing Matt talk about pahticles.