Where is antimatter hiding? - Physics explains the mystery of missing antimatter | Don Lincoln

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[00:00:02]The virtual particles refer to matter and antimatter particles coming to life.

[00:00:09]>> Correct.

[00:00:09]>> Can we just talk about the the antimatter part of that? So it's starting with Paul, one of the most legendary examples of math leading to physics. So the math suggesting that so something like an antimatter should exist and Paul Durak taking it seriously and then eventually showing that it does exist. So what evidence do we have for antimatter? So antimatter was predicted in 1928. Paul Durak was trying to merge quantum mechanics and relativity because the original Schroinger equation did not was not relativistic. And in doing so he basically the equations were complex but in the end it came down to something like equation squar= 1. You take the square root of both sides you get equation equals + one or minus1. Plus one was the electron minus one was something you didn't know what it was.

[00:01:02]Um there was some conversation for a while thought maybe it might be the proton but that didn't seem to work out and so he insisted that his equations were right and that there was an antimatter he didn't call it an antimatter but a positively charged uh sibling of the electron what we now call the posetron the antimatter electron so it was predicted it was discovered in 1932 by Carl Anderson and his student Seth Netto they saw saw an antimatter electron and that was pretty cool. So that right there they knew it was real. Antimatter was predicted. It was observed. That's that. In 1956 the antimatter proton was created and that required a large particle accelerator high enough energy um to to to make it and that was done at Berkeley and a year later the antimatter neutron was discovered. So at this point and now jumping ahead to now we can make using uh energy by smashing particles together we can make antimatter protons.

[00:02:09]We can make antimatter electrons. We have gone so far to make anti-atter helium nuclei. So we have made two anti-rotons and two anti- neutrons. Combine them together to make an anti-atter helium nuclei. This has been done, been observed. No question. At CERN, they have gone so far as to make antimatter hydrogen. They take a beam off one of their lower energy accelerators. They make anti-atter protons. They collect them. They slow them down. They cool them to almost absolute zero. They take um sodium 22, which makes antimatter electrons. They slow them down. They bring them together. They coales them and they make literal antimatter hydrogen atoms with an antimatter proton surrounded by an antimatter electron.

[00:03:03]And they have done incredible measurements. They have agitated the atoms and caused it to emit light. They have looked at the light that comes out of antimatter atoms. And the question is is does the light coming out of antimatter hydrogen atoms have exactly the same spectral characteristics as ordinary hydrogen which we predict that it does and the answer is it does. So the tests have been staggering. We now know a great deal about antimatter hydrogen. recently recently like 2023 I believe it was one of the experiments called alpha at CERN made antimatter hydrogen put it in a bottle and released it and watched which way it would go.

[00:03:48]Did it fall up or did it fall down?

[00:03:51]Because um while it kind of makes sense maybe to think that maybe antimatter falls up in the same way that we have Kulum's law, you've got electric charges and they might attract or repel. Um however, there was lots of ample theoretical reasons to believe that antimatter also would fall down. So they did this fantastic measurement and they first they put in hydrogen and they calculated that some if they did this something like 80% of the hydrogen atoms would fall through the bottom of the bottle and 20% would go through the top just because um gravity is very weak and the atoms will escape wherever they do but there will be a bias pulling hydrogen atoms down. So they did the exactly the same thing and what did they find? They find that antimatter falls down. Now they do not have a good enough measurement at this time to say that the gravity that antimatter experiences is 100% that of matter. What they have measured is that antimatter fell down with 75% the strength of regular matter.

[00:05:05]But there were big uncertainties. There was plus or minus.13 due to the experiment which was good but imperfect and plus or minus.16 due to their um their theoretical model. So it's like 75 plus or minus something like 29 and that means there's a good chance it's between.5 and one which means it's consistent with one. So they are improving their measurements. Well, if I can, I would love to take a bit of a tangent on that topic because I went down a rabbit hole watching some of your videos on antimatter and I mean, Fermy Lab was the hub for the production of antimatter for quite a while.

[00:05:48]>> It was >> I saw that NASA said that the global estimate for the current rate of production of antimatter is 1 nanog per year. Can you speak to how hard was it to make antimatter? And also you did mention in a video that you know if matter and antimatter meet they produce a lot of energy.

[00:06:10]>> I think 20 grams of antimatter is equivalent to a 1 megaton nuclear warhead in terms of explosive energy.

[00:06:19]Yeah. So all those questions together.

[00:06:20]So how hard is it to produce antimatter?

[00:06:23]>> It's freaking hard. Okay. All right. So here's the deal. So at the time until 2011, Firmay Lab was the most powerful anti-roton production facility on the planet. Every 2.3 seconds, we would smash 10^ the 13 protons into a target and we would get out 10 to the 8th anti-roton. So basically in order to get a single anti-roton we needed to smash 100,000 protons into material. So every 2.3 seconds we would get of order 10 to the 8th antiprotons. And what we would do is we would collect them over the course of 12 hours or so. And we would get in the end we would have to collect them and cool them down and so forth of order 10 the 12th anti-roton every 12 to 24 hours. So 10 the 12th sounds like a lot. It really does. That is a trillion.

[00:07:26]But you need to remember that a gram of antimatter is 10^ the 23 antirotons. So that means over the course of a day we were able to create something like 100 billionth of a gram.

[00:07:43]And so if we did that for a year then that would be about a nanogram. So about a nanogram a year give or take. That's that's a reasonable estimate. So a nanog one billionth of a gram. So that means at that rate with that facility it would take a billion years running with very little downtime to make a single gram of antimatter. If you combine 1 g of antimatter and one g of matter together the energy release is equivalent to the combined Hiroshima and Nagasaki explosions. So that tells you if you wanted a megat ton you need about 25 times more. So you would have to run for 25 billion years to get a megat ton of explosive power.

[00:08:32]>> Let me uh lay it all out because I think it's pretty interesting actually. This is a NASA estimate of how much it cost to produce antimatter. So looking at all the the cost of the accelerator, all everything combined together to do enough for a one megaton antimatter bomb of such a thing would be even possible on the order of 25 grams like we mentioned will cost about based on the NASA estimate uh $1.5 quadrillion.

[00:09:02]By the way, uh NASA wasn't talking about a bomb. It's just me adding NASA was talking about the estimate the cost of 62 to63 trillion per gram of antihydrogen actually is what they're referring to.

[00:09:17]Uh so compared I was looking at estimates the current best estimates how much it takes to produce a 1 megaton nuclear warhead everything combined is about 10 to$50 million in the United States. So you're talking about difference in terms of a weapon with equal power $50 million versus $1.5 quadrillion.

[00:09:39]To me what's interesting weapons is just one uh indication of this. One other possibility and NASA also writes about this is the use of antimatter and propulsion systems >> right >> uh just like you can use uh nuclear fusion and maybe even nuclear fusion down the line in propulsion systems. I saw that one gram can help get us to Alpha Centauri star system. If we can get to 02 times the speed of light in 20 years, uh meaning it would take us 20 years to get to Alpha Centauri. Is any of this a possible future? The use of antimatter for generation of energy because we should mention that it's extremely compact. It has the obvious downsides that it's extremely costly to produce.

[00:10:27]We don't know how to do that kind of scale.

[00:10:30]>> The upside is it's compact, >> very powerful. So the short answer is it is not a physics problem. It's an engineering problem. So I have people for that. Okay. Um, okay. But no, no.

[00:10:43]Um, the truth is that antimatter, >> if you are able to, uh, assemble it and store it, sure, it would be able to take that antimatter, heat up matter and shoot it out the back of a rocket and it would, you know, do what rockets do and it would make us go quick and that would be fine.

[00:11:03]>> And we should mention the thing that you just mentioned is is correct. One of the hugest challenges is the containment.

[00:11:08]Oh, because >> anti- matter when it comes in contact with matter >> is a is a problem, >> right? So, if you were unable to uh to contain your trip to Alpha Centuri for even a millionth of a second, boom. And that would not be good.

[00:11:25]>> Yeah.

[00:11:25]>> Um, you know, it reminds me of the uh the Star Trek where Scotty saying, "Captain, you know, the antimatter pods are about look, we're losing containment going to blow." And that's exactly what would happen.

[00:11:38]So the short answer is yes, antimatter as in principle we could make and use as a a source of energy, but there are probably far less expensive sources of energy. Um, you know, it depends on what you need to do. The Voyager probes are still chugging along with plutonium now.

[00:11:58]They're running out of energy at this point, but we could, you know, presumably do a somewhat better job if we needed to. So, I I like the idea of antimatter, you know, but the reality is the danger, not the obvious danger of weapons, but the danger of if you wanted to be in a ship run by antimatter, if it ever got loose, well, you you would never know it. That would be that.

[00:12:22]>> The reason I I I find this kind of inspiring is antimatter is in the space of physics that has a lot of mysteries. There's a lot of exploration to be done. And so this kind of connection to energy means that uh if we have a bunch of breakthroughs on the antimatter side that might lead to a better propulsion system, better energy generation systems >> in principle.

[00:12:48]>> There's some combination of engineering here, but there's some combination of understanding the fundamental physics.

[00:12:54]>> I mean, we know how to do this.

[00:12:57]You know, we we know you take energy, you make antimatter. You have to contain it, you have to store it, you have to do all the hard things. But I I would be shocked if there was some like new addition to the theory that made antimatter production easier.

[00:13:13]>> Interesting. So, we know how to produce antimatter with accelerators. You're saying there's not breakthroughs in physics that could lead to different mechanisms for the generation of antimatter.

[00:13:26]>> You have to concentrate energy. That's it. If there's another way to concentrate energy, that would work too.

[00:13:32]>> And our best knowledge of how to concentrate energy is the accelerator.

[00:13:35]>> And remember, we're talking concentrating it into um volumes the size of a proton. I mean, if you concentrate it to the size of your thumb, well then, you know, it's really the density that matters, the local density. And so, when you smash two protons together, all of that's occurring in a tiny tiny volume. So, it's the local density of energy that matters. If you had a lot of energy in a thimble or something, >> it's probably not dense enough. You know, it really has to be in close proximity for that to happen. And then when it does, it it's it's okay. So So if there's another way, we know how to do it to to make that that density thing with with accelerators. If someone has a bright idea on how to make highly dense energy then yeah uh making antimatter is a piece of cake but that's the crux concentrated energy.

[00:14:30]>> Yeah and how to do so in a cost efficient manner not trillions of dollars.

[00:14:36]>> Well yeah so one of the big mysteries with antimatter is the bigger why.

[00:14:42]Where is the antimatter that should kind of be there? If the whole idea is that anytime you generate matter, you generate the same amount of antimatter.

[00:14:52]And yet, when we look out into the observable universe, it seems like there's not antimatter for the most part there. Correct?

[00:14:59]>> So, what do we understand about this mystery? What are the possible explanations as to why? So there's this thing called um biogenesis and and as you say so reiterating a little bit what you just said um these are both Einstein things Einstein says that when you take energy you make matter and antimatter in equal quantities and Einstein says after the big bang there was a lot of energy in the universe which should have made matter and antimatter we only see matter where' the antimatter go and the answer is we don't know >> however there are some ideas And there's a lot of thinking on it and um in fact for me it's doing an experiment right now with nutrinos trying to to better understand what it was that made the matter and antimatter not be the same.

[00:15:51]Now we do have a measurement of how much different it should be. And it's kind of neat. We can do this by counting the number of protons in the universe just looking at galaxies and so forth. And then we can look at the cosmic microwave background which is sort of the aftermath of the big bang. And we can count the number of photons from the cosmic microwave background. And with a little bit of math, what we can do is we can then say that somehow in the early universe, something made a very very tiny asymmetry.

[00:16:28]So that for every billion billion with a B anti-atter particles that existed in the universe, there were a billion and one matter particles. Mhm.

[00:16:41]>> The billions canled, annihilated, destroyed each other, and that extra one that's left over is us.

[00:16:47]>> Mhm.

[00:16:48]>> And so what physics mechanism made that ever so slight asymmetry is not understood. There are some thoughts. One thought is uh that well, it's just how it was when the universe was formed. There was an asymmetry. It was not made by matter. or an antimatter.

[00:17:11]Another possibility is um there are various numbers of theories all under the word beriogenesis and berio um coming from word berion which basically means protons and genesis meaning the creation of and we'd say that simply because the protons are the heaviest particles and so beriogenesis is just the creation of matter and there are just a number of theories in quantum mechanics that say that matter and antimatter can can oscillate ate back and forth into one another. And there is a slate slate asymmetry in how that happens. And we know that this is true to a degree. Um we've measured it in the 1960s with a a different form of matter.

[00:17:58]I mean, you know, not protons, but a a a type of ephemeral matter that only exists in particle accelerators. And so we know that there is a slight difference between matter and antimatter, but it's not enough. It doesn't explain that. We're not sure.

[00:18:12]So, at Firmeny Lab, we have this idea which kind of turns things on its head and it it's not buriogenesis, it's leptogenesis. So, leptons are the electrons and because Firmeny Lab is currently the world's most powerful nutrino accelerator and nutrinos are leptons.

[00:18:34]There is this idea. Now leptogenesis is incredibly complicated but the idea is that it is possible we we know that nutrinos actually change their identity.

[00:18:46]There are three different types of nutrinos like uh I don't know cats and jaguars and tigers and if you have a beam of just cats if you go along a little while you find there's cats and jaguars and then tigers and then they'll be back to all cats again. And so this oscillation thing is called nutrino oscillation. And we've known it's been true since 1998.

[00:19:06]And what we are studying is we're going to make a beam of nutrinos and another beam of antimatter nutrinos. And we're going to study the oscillation behavior of the two of them. And it is possible.

[00:19:19]It is unlikely, but it is possible that the two of them will oscillate at slightly different rates.

[00:19:26]>> Mhm. And if the nutrinos oscillate at slightly different rates, then that along with several other highly improbable things can tie together and might explain why there is more matter in the universe. So if I was going to bet the farm, I'll bet that they oscillate at the same rate. But I don't know, and you don't know till you do the measurements. So that's what we're doing. There are some other uh experiments trying to measure it right now. So there's a big race between the Firmeny Lab group and another group in Japan to see who gets there first and make this measurement and we will find out. If it turns out though that there is a difference in this oscillation rate between matter and antimatter, it will be a huge clue in this very very difficult puzzle. I wish I could tell you I knew what the answer is but but literally nobody knows. I mean, and that's the thing of being a research scientist like me is if you're not confused, you're not doing your job.

[00:20:26]>> So, there is this desperate or not desperate, exciting search for this tiny asymmetry.

[00:20:33]>> Yes.

[00:20:33]>> It's so so crazy to think that everything we see around us is a result of this tiny asymmetry that there was this gigantic annihilation of matter and antimatter in the early universe.

[00:20:47]>> And this is just some little accident.

[00:20:50]>> Yeah. Yeah. That's crazy.

[00:20:52]>> It's a happy accident. That is just I mean it's totally crazy.