Are You REALLY Made Of Stars?

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1:29Hello, welcome to the Rest of Science with me, Hannah Fry. And I am Michael Stevens. Question for you, Michael. What are we made of? Ugh, we're all made of stars. Yeah. Or are we? As you can tell by my sarcastic tone, I'm not a big fan of that phrase. It gets spoken a lot, but today I want us to really answer the question, what are we made of? You don't like the explanation that we're forged in the heart of dying into galactic cosmic collisions. Oh, it's so inspiring. Oh my gosh. Spewed out by supernova explosions. I mean, obviously we are. We were. Okay, but wait, when you say obviously, why so obviously?

2:06Oh, well, because we're made of matter and that matter wasn't created by our mothers in the womb. Ex nihilo. Okay, from nothing. It was already there and it was rearranged into us. And before we were here, it was something else. Because the atoms come from elsewhere. The atoms came from elsewhere. And then you ask, well, where do the atoms come from? And they formed early in the universe. And then heavier and heavier nuclei, more and more elements were formed by stars. smashing them together in their cores and then dying and exploding and all of their guts coalescing into new stars and planets and people.

2:39So we're made of stars, mostly. I guess the point is that it's very rare that new atoms get made on Earth. Would it have like a little atom factory where it's like, how many carbons do you want? How many oxygen do you want? These atoms only exist because of these high energy explosions that happened in intergalactic collisions. It depends what you mean by made. Go on. Okay. So there are a lot of radioactive isotopes of very common things like potassium and carbon that are always like converting and decaying into things. I don't think I'm not counting decaying. I'm not counting decaying. I want, I want, what's the opposite of decay?

3:16Re-up K. D-K, re-K. Just K. K. You can decay. Can you just K? I want, I only want K. Yeah. I mean, I can't go to the store and say, oh, I need carbon. I'm looking to, you know, grow. Build a baby. Yeah. It's like, if you want carbon, go eat a potato. But that potato got the carbon from the soil, which got it from a star that died billions of years ago. So hang on. This all sounds completely legitimate to me. It does. And that's why I say mostly we are made of stars. Yeah. I like to say that we are made by stars. Go on. First of all, the very lightest elements, hydrogen. Okay. There's a lot of hydrogen in our bodies.

3:58Sure. It's part of H2O. See episode one. See episode one, yeah. As the universe cooled, protons could start to hold on to electrons and, oh, you've got hydrogen. So a lot of the hydrogen in your body wasn't made by a star. It was just made in the very early days, even before stars existed. Feels a bit pedantic, but go on. How is that pedantic? There's an enormous amount of hydrogen in your body. Excuse me, actually, you were made before stars. Now, OK, to be fair, that hydrogen was probably in a star before it was in you. Sure. It wasn't made. Well, OK, so you are you're made. Yeah. All right.

4:37Fine. That one that one I'll give you. OK, deal. You're made of that of stars there. My knockdown point is boron and beryllium. Go on. Hydrogen to helium to lithium. But then in nucleosynthesis, the process inside stars that forms new elements, you leapfrog all the way from number three, lithium, to number six, carbon. And four and five, beryllium and boron, are not made in stars. Well, where are they made then? They are made by cosmic ray spallation. I beg your pardon. So this is where I get the whole, we're not made of stars, we're made by stars. Because cosmic rays often come from stars. We're not entirely sure everything that they might come from, but they are extremely high energy particles.

5:23They're not rays of like, you know, a laser or something. They're little cannonballs. And they're flying through space, often from stars that supernovaed many, many years ago. When these hit other atoms, they can cause that atom to explode. that can cause things like neutrons to fly around and then those things fall into other atoms and that is how beryllium and boron get made. So hold on. Not in a star, but around a star or potentially really far away from a star. By a star. So right, right at the beginning we said, what are you made of? Stardust. And you disagreed. And to prove that you're not a pedant, we've gone all the way around the houses and come back to you saying, It's not.

6:08We're not made of stars. We're made by stars. We're made by stars of stuff. You're absolutely right, Michael. Not pedantic at all. Hang on. Right. How much boron and beryllium is there in the human body, though? I've known this my entire life. So your body contains about 35 micrograms of beryllium. And every day you drink about between 0.2 and 0.6 milligrams of boron in your drinking water. Now, earlier I told you that boron had no... You're really adding to this pedantic thing here. Like, okay, you have to say by stars, but because 0.35 micrograms of beryllium is in your body. We said, what are you made of?

6:53Not what is most of you made of. I just think, here's the deal. I'm not being pedantic so much as I love that I get to have this conversation every time someone says, oh, we're made of stars. I can be like, well, boron and beryllium are technically in your body and they're made by cosmic rays spallation. So, all right. I do that all the time. And there's not much. This is why we love you, Michael. You know, if you support me, eat some kidney beans, eat some avocado and kidney beans and wash it down with prune juice. Those are our highest dietary sources of boron and beryllium. Or just chew on a boron rod.

7:31That's what my dad always used to tell me. But guys, let's talk about the things that make us, not just what they make us out of. Cosmic rays. Because actually, cosmic rays, there is a whole fascinating journey that we're going to take you on in this episode about cosmic rays that bring us to life itself. But also, a cosmic ray helped a Super Mario speedrunner achieve the impossible. Yeah. I guess we should start off talking about what cosmic rays are. I mean, you described them as star puke, which I think is, I mean, frankly, that's all we need, isn't it? It's more than puke. It's better than puke.

8:06It's more violent than puke. It's the entrails of a star in many cases. I mean, because here's the thing. Okay, space is sort of, it feels like it's like lots of blackness, but actually space is extremely violent. There are, you know, dying stars that explode into supernovae. the sort of stars that are tearing themselves apart in these explosions that are so big that they can outshine actual galaxies. I mean, you also have like black holes smashing into one another. You've got like actual galaxies smashing into each other. It's all sorts of stuff that is throwing debris all over the place across space.

8:38And that debris are the cosmic rays. Exactly. A cosmic ray is not a immaterial flash of light like a ray, like from a laser gun in a movie. it's just really really high energy fast moving particles like protons and and helium nuclei and stuff yeah because a lot of the stuff the debris that's throwing throwing around is going to be planet-sized or moon-sized or you know just like big rocks but tons of it tons of it a lot a lot a lot of it is is the size of single atoms or single you know atomic particles basically that's right and these things are not just like rare they are flooding the universe i mean how many times am I being hit by a cosmic ray every day?

9:18Even now. In this moment. A lot. So the calculations are that every square metre at sea level, well, sort of at sea level-ish here, gets 10 ,000 of these space bullets every second. Every second. Right. It's an enormous, enormous number. I mean, it's sort of like imagine that the Earth is kind of sitting in a bar during a sort of Western-style shootouts, right? There's the stuff flying everywhere. And we are actually protected from a lot of it because of our atmosphere, because of the magnetic field that the Earth creates. It kind of protects us from a lot of this stuff. But still, it's this constant barrage.

9:59And we don't feel it at all. No. Mostly they pass right through us, I'm sure. Well, okay. So it depends, right? These protons are like heading straight towards Earth. And of course there's a lot of atmosphere between between us and and sort of outer space you know just by chance at some point this proton is going to smash into a particle that gets directly in its way and at that moment they don't just bounce off each other right you can't just think of them as sort of like normal bullets okay you end up with this fireworks display of loads of different types of subatomic particles so you get quarks you get gluons and then they go on to sort of combine and then split into all these other particles you get mesons you get muons you get neutrinos, you get photons, a little flash of light, you get hadrons.

10:41And loads of these just decay away almost instantly, apart from muons, which is sort of like, it's kind of like a heavy electron. And those survive just long enough to hit down at sea level to come down to Earth. But they shouldn't. But they shouldn't. Yeah. They shouldn't. They decay so quickly that even at the speeds they travel, they shouldn't reach the surface of the Earth, and yet we detect them. They're being created as shrapnel from cosmic ray collisions in the atmosphere, and we detect them down here on the surface. And yet that became some of the earliest evidence that Einstein was right, that the faster you go, the slower time passes for you.

11:21These particles were decaying exactly when they should. It's just that time was running so slowly for them compared to our time that their brief lives allowed them to travel all the way to Earth's surface. Exactly. So these things, they decay extremely quickly. They last for 2.2 microseconds, right? I mean, less than a blink of an eye. But even if they were traveling at the speed of light, 2.2 microseconds only lets them travel about 660 meters, really not far at all. And yet the atmosphere is like 15 ,000 meters thick, 15 kilometers up in the sky. So if classical physics were right, you would never find any muons down at the ground from cosmic rays.

12:00And yet, exactly as you say, you find you measure them and there are thousands per square meter. Wow. So we live constantly in a shower of cosmic rays and the residue of cosmic ray spallation. That stuff's called spall, which is what you basically call shrapnel when it's not a weapon. It's just stuff that flies out, some of which are these time traveling particles or time dilating particles. You can see them there, can't you? You can make like cloud chambers to detect them. Yep. Yep. Didn't you make one of those when you were a kid? I did. My mother somehow allowed me to get a bubble chamber from this catalog.

12:33and it came with the chamber, but it also came with a needle tipped with radioactive lead. And she made me keep that in the garage. I don't know how she approved all of this. Sorry, your mother, who didn't let you say crap or damn, Until I was in my 30s. allowed you to get a radioactive lead needle. First of all, I still can't say damn. Okay, sorry. I am allowed to now say crap and piss. Piss seems a lot worse than damn, I got to tell you. But anyway, I don't think she fully understood what it was. And then when it came in this special test tube with radioactive warnings all over it, she was like, oh.

13:14And then I told her, oh, so I also need you to take me to the store to get some dry ice and the highest proof alcohol you can buy. Because hold on, we should explain what these things are. You basically get, I mean, imagine sort of an unused aquarium that you might house a fish in, right? Sort of that kind of thing. And then you create a layer of alcohol vapor, sort of really, really chill it using dry ice to create this layer of alcohol. A super critical layer that's just ready to condense. It just needs the littlest provocation and it can get that from cosmic rays. A little muon. A little muon flies through and then you see a trail.

13:52Like a contrail almost. A contrail from an airplane basically. You see that and it's this quick streak of slightly wider, very thin like a spider silk. And that is radiation from above. Hold on. What was this radioactive needle for? Oh, well, you needed a source of radiation because background radiation is not enough to get cool results in the bubble chamber. It was a very simple one. But you could stick this needle through a little hole in the chamber. and then you would see it looks like wisps of hair constantly coming off of the needle. It was lead. It was a lead isotope that was radioactive.

14:31Where is it now? I don't know. Just out there giving someone else cancer. I should ask her what happened to it because it sat in the garage, but she sold that house years ago. So it could still be in that garage. Maybe we should go and check in on the people. Maybe she ate it. I'll give her a call after we record, but yeah. If she suddenly gets extra senses. She can like climb buildings or shoot spider webs out of her arms, you know. That's how you detect muons, right? Using cloud chambers. You can also do it where you get great big tanks of water and look for little flashes of UV light. You can also do this on the atmosphere where you kind of have loads and loads of mirrors and just wait for that head-on collision of a cosmic ray and some sort of particle in the atmosphere.

15:16it and when you do that based on the intensity of the light you can tell how much energy that space bullet had right now that sort of piece of shrapnel had and loads of them most of them have low energy right sort of 10 to 80 percent the speed of light well you know the slow guys yeah so slow not really bothering and solar flares and and you know big ejections from the sun they'll spit out these sort of protons that that i mean they make life quite interesting for astronauts to be fair um in what way oh because if you are orbiting the earth if you're like in the international space station so you're outside of the protective layer of earth these cosmic rays are coming in and not hitting other particles before they decay and and reach you astronauts when they're on the iss report seeing flashes of light the cosmic ray interacts with the the neurons in their brain and make them think they're seeing things that are not there or tasting things that are not there.

16:08No kidding. Like flashes of metallic taste. Just like this sort of interruption. Oh, yeah. So that would be a concern for long distance space travelers. If you want to go all the way to Mars, you're really leaving the protection of Earth and you're going to be hit by cosmic rays directly a lot. But these are the low energy ones that we're talking about. So every now and then you get a medium energy one, 99.9 % speed of light, right? Those are coming from supernovae. They're coming from pulsars, that kind of thing. But then in 1991 in Utah, they had all of these mirrors in the sky, pointing to the sky, doing this big experiment, looking for cosmic rays, trying to catch this very faint flash of ultraviolet light that happens when they slam into the atmosphere.

16:50And they found one, they recorded one that was traveling at 99.99999. I mean, I can carry on going. It's 21 nines, right? 21 % the speed of light. 21 % the speed of light, yeah. Nine, 99.9999, 21 of them, 5 % the speed of light. Are you describing the oh my God part? I am describing, this is what it became known as. It wasn't going the speed of light. But to put it in perspective, at the speed it was traveling, if it entered a race with a beam of light, after a quarter million years, the light would only be one centimeter ahead of it. It's basically moving at light speed. And it hit Earth and we detected it.

17:30And we called it the oh my God particle. Most of them aren't that fast. No, but I mean, this one, the amount of energy that this had to get a particle to be traveling at that sort of a speed. This one, it basically had the same energy as a baseball traveling at 100 kilometers per hour. Right. But it was in a single particle. In a single particle. Subatomic particle. And this is it. No one still has any idea what kind of violent collision would produce that kind of space shrapnel. I mean, it's a real genuine mystery. And it's not the only one. They've seen other particles with similar amounts of energy.

18:06Do they know the general region the Oh My God particle came from in the sky? I don't think they do. Not from a single particle. You can only really, you can tell when there's a lot that come from a particular direction. But also remember, I mean, these things might be traveling close to the speed of light, but they've probably been traveling for billions of years. Like what you are seeing. In our time. In their time, it's no time's passed almost. Sure. But in our time, it's billions of years. And, you know, quite often these things are sort of like the ghostly remnants of ancient, ancient star collisions older than the sun.

18:42You know, and these bullets like passing through you all the time. Imagine being that particle you formed in the early days of the universe and then you traveled and you watched in very fast motion the universe age and you traveled a long distance and eventually you wound up on the one planet that could detect you and talk about you on a podcast. What a life. What a life. What a life. I know more about the third most powerful cosmic ray detected, the Amaterasu particle. This one was detected just in 2021. It had the energy of a brick being dropped from your waist onto the ground. In a single particle.

19:18In a single particle. But what's cool is that we tracked where it came from. And it came from the local void, which is exactly what it sounds like. It's a nearby area. Well, nearby. It's far out from our galaxy and all the galaxies around us where there's just nothing. There's nothing there. And yet it's pitching these cannonballs at us or one cannonball. We don't know where it came from. It could be just a property of space itself is the creation of these particles. That's incredible. Because also, I mean, think about how small Earth is. This thing could be, there could be something going on in the deep void that we don't know about.

19:54They're spewing out all of these in all sorts of different directions. And we just so happen to have been looking in the right place at one moment where one just so happened to be passing. I'm sure even more powerful particles have hit Earth. But we're not always looking. We've only been talking about particles that scientists have detected with experiments watching for them. But I think that we've also been affected by massive cosmic ray high energy particles doing really interesting things when we weren't even expecting them. For example, in 2016, there was this woman named Mary Moe, great name, by the way.

20:31She was on a flight to Amsterdam and she had a pacemaker. And suddenly in the middle of the flight, her heart just starts beating like crazy, like she can see it beating. And the rhythm is all off. They do this whole emergency ambulance pickup when they land. At the hospital, they determined that the pacemaker had entered its backup processing mode where it has like a default rate and impulse strength. It was not what was prescribed for her. Why did that happen? The leading explanation is that a single bit in the computer of that pacemaker was flipped. Okay. The memory and the language of a computer is stored in these electrically charged bits.

21:15and a charged particle that results from a cosmic ray collision in our atmosphere can interfere with these bits and flip them. They can only be one of two things, on or off, one or zero. You flip one of them, that might have been enough to cause the pacemaker to go problem, resort back to default processing mode. And that's probably what happened. Change a one to a zero and these are potentially the consequences of it. So, so far we've been talking about cosmic ray particles that have been detected by scientists using experiments that were watching for them. But we have evidence of high energy cosmic rays doing really interesting things when we weren't even expecting them.

21:55Actually, when you consider how much electronic equipment there is, I mean, in the sky, in planes, for example, the fact that this can happen, the fact that a cosmic ray can interact with electronic equipment, change a one to a zero or a zero to a one, sometimes it can have these really catastrophic consequences so mary's pace breaker being one there was also there was a um a quantus flight this is in 2008 and the plane's kind of going in the sky all happy and then twice in 10 minutes it does a nosedive right lots of people end up getting injured on board just really sharp turn and when they did this investigation they found that there was this erroneous computer data going on in the onboard systems that misrepresented the angle at which the aircraft was flying.

22:43So you can imagine actually a one to a zero or zero to a one in that situation would make a huge difference if you're at like there's quite a big difference between five degree angle and 15 degrees you know or minus 15 degrees or whatever it might be. A lot of people the explanation that people think is that it was cosmic radiation that a particle from outer space from some intergalactic collision billions of years ago, traveled across the galaxies and interacted with that computer at precisely the right moment, precisely the right way in order to confuse the onboard systems. Not frightening at all.

23:18Not frightening at all. It's not just planes that are affected, though. And after the break, I want to talk about how it could be affecting your gaming. The most serious. The most serious pacemakers and crashing airplanes.

23:44all right before the break we were terrifying everybody ever whoever wants to get in a plane again what we should add is that there are now systems in place error correcting codes that account for this you don't really have computer systems in a in an airplane anymore that are just solely responsible for the angle of the aircraft. Should I do a nosedive or not? Yes, exactly. We've moved on a little bit from there, you'll kind of say. But before we get on to the gaming story, which is extremely serious, I do want to add in the fact that those examples, so the Qantas flight and Mary Moe, happened at high altitudes.

24:21I think it's probably not a coincidence because, of course, you are more likely to interact with these particles the higher up you go. and actually this is the the the reason why we know that these things exist in in the first place so okay back in 1900 or so um this is a point people knew about atoms they knew about radiation they knew how to detect it but everyone thought that the radiation that they were detecting this sort of background level was was probably coming from the sun sure the sun was spitting out of this stuff and then there was a guy called victor hess um 1912 this is he was like i've i know exactly how to test this i know exactly how to work out whether this is coming from the sun why don't i get into a balloon filled with hydrogen go up into the sky um and measure how much radiation there is up there and by the way why don't i do this during a solar eclipse perfect yeah because then when it's dark and i'm in my uh you know five kilometers high in my frankly explosive explosive balloon uh with just a little dangly basket and some victorian woolly gloves on that's the point at which I'll be able to know whether it really is coming from the sun or not and what did he find?

25:30I mean not only did the radiation not decrease during the eclipse but it increased the higher up he got so he had these two little gold leaves that will flutter you put a little charge through them and they kind of get attracted to each other when there's radiation so they flutter in the presence of radiation and he measured that actually the higher up you go the more these things start fluttering and the solar eclipse made basically no difference whatsoever Right. So the sun wasn't the source. Exactly. So that was the conclusion that he made, was that the only way that it could be happening is that it's from deeper in space that these things are coming from.

26:06And when was this? 1912. Nice work. So pre-health and safety. He did get a Nobel Prize for it, to be fair. It kind of makes it worth it. Do you think so? I would do it. Would you in a hydrogen balloon? For the views. Everything's content, baby. Go on. Tell us about Cosmic Rays and Gaming. Well, OK, look, in 2013, a speed runner who I'll explain speed running is my favorite kind of gaming content to watch. It involves completing tasks or completing entire games in video games as quickly as possible. Finding ways to optimize your strategy, whether it be the decisions you make or even the moves that you make to break the record and finish the level or the game or whatever, whatever the challenge is.