What's the smallest piece of matter? Is there one?

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Speaker 1: Pretty much all the stuff that we're made out of. Me and you and cats are made out of quarks and electronics. We cats are made out of something strange though, right, Yeah, some people sinspect cats come from another dimension. We made little weird particles, and that would explain a lot um. But so far, everything that we've ever interacted with, all the history of science, everything we've been studying for hundreds of years, um is only studied stuff that's made out of quarks and electrons. And so for a long time we thought, well, maybe everything's made out of cork and electrons. Right, We've never seen anything else. Hi, I'm Daniel and I and this is Daniel and Jorge Explain the universe. Today we're going to talk about dark matter. What is dark matter anyway? How dark is it? Does it really matter? I mean, who cares? Right, Well, hopefully they care because they clicked on the podcast. Well, dark matter certainly matters to us, and so today we'll be talking about all the interesting things about dark matter, all the mysteries and amazing facts that we've know and don't know about dark matter. So what do you think dark matter is? We went out in the street and we asked people what they thought. Here's what they had to say. Ah, I don't remember. It's like black holes, right and stuff like that. Lava, I don't know. I'm thinking it's like this dark mass that I have no idea what's in it, but it's just a dark mass. Cool. Wow. People have some pretty interesting ideas about what dark matter is and what dark matter isn't so I think it's pretty good that we're going through this to explain all the details of dark matter. Yeah, and it's interesting that most people seem to have heard of it, but people sort of don't quite have a good grasp of it. Well. I think there's also a lot of abuse of the phrase dark matter you see in science fiction. It's the title of several albums and bands that have nothing to do with dark matter. So it sort of entered like the pops popular lexicon without carrying along with the possibles. I would like a dark matter popsicle. Um, it's under the popular lexicon without sort of carrying along with it what it actually means. So this phrase which exists in the language, and it's been stripped of scientific meeting and lots of content. I know that I've read a lot of science fiction novels that talk about dark matter title dark matter and have nothing to do with dark matter. Right, So it's just two words that are tailor made for like science fiction, right, dark and like matter. You know, like that's a great triumph. It's a great triumph of marketing. Right, it's an awesome sounding theory. Yeah. Yeah, secured those jobs for those physicists, that's right, that's how we get paid. Yeah, coming up with cool names for theories. Well, we came up with the list of the four things you should know about dark matter, and the first thing you should know about dark matter is that it's a different kind of matter than what you and me and Daniel are made out of. So, Daniel, what does that mean that it's a different kind of matter. That's a great question. Well, to answer that, we really have to think for a moment about what we're made out of. Right, I'm made out of particles. You're made out of particles. This chair I'm sitting on his mating out of particles. Everything we know pretty much is made out of particles. Particles like atoms. Yeah, particles inside atoms. So you have the molecules your body is made out of, and those are made out of atoms like hydrogen and lithium and that kind of crazy stuff. And inside those are smaller particles protons and neutrons and electrons, and inside those, generally down even further are quarks. Everything in the universe, um, everything out there that we've seen is made out of these things quarks, electric right, that's right, it's the stuff we can see, and and we what can we see where we can see stuff that sends us light like stars. We can see stuff that reflects light, like gas and dust and and stuff like that that reflects light from other stars, like the moon. Right, the moon doesn't give off its own light, it's not doesn't shine, but we see it in the sky because it reflects the light from the sun. So it's something that we can see. It's a kind of matter. We know, we understand it. I can think about everything's made out of these three things. But dark matter is something different, right, dark matter is something else. It's a different kind of matter. It's not made out of quirks and electrons. And there are even other weird kind of quirks that we discovered, like by smashing particles together. And we know dark matter is not made out of any of those, something of any kind of quirks or even weird kind of electrons. It's something else, something different, something new that we don't know what that is. We don't know what that is at all. We don't know if it's another kind of particle. We don't know, if it's a weird new kind of matter, this not made out of particles. We don't know, if it's something we haven't even imagined yet. That's my personal fantasy is I hope that when we do figure out what dark matter is, it totally blows our minds and turns out to be something that even science fiction writers that never thought of. That would be my my favorite scenario. So it's something that's made out of something entirely different than us. But there's a lot of it. And that's the second thing you should know about that we wrote down we should you should know about dark matter, which is that there's a ton of it in the universe and it's all around us. That's right. Dark matter is everywhere. So people talk about dark matter like, oh, it's it's weird stuff out in space, or these other galaxies have dark matter, But dark matter is all around us. It's there's a huge blob of it in the center of our galaxy, and then there's a big diffuse cloud of it that's that envelops the entire galaxy and pretty much every galaxy out there. Dark matter is matter. It's stuff, right, And when we say it's matter, we mean that it feels gravity. And that's actually how we figured out that it's there. After all, matter something that feels gravity. But wait back up a second. So it's it's like there's blobs of it floating out in space. Is that is that kind of what we know about dark matter, Like it floats and blobs. Dark matter definitely forms blobs because it feels gravity, and like anything else, things that feel gravity are going to slowly accumulate and pull themselves together. So just like normal matter, you know, the gas and the dust pulled themselves together to form stars and galaxies, dark matter also pulls itself together and form these big blobs. So those blobs aren't like out there in space, they're on top of us. They're here with us. If you lift up your hand right now and wave it all around, you're passing through a huge blob of dark matter that's there in your living room or kitchen or car or wherever you happen to be. It's like in the air around us, Um, what does that mean? Like, it's like it's in the space between regular particles. It's here with us, and there's a lot of space between particles. Right, particles are super duper super tiny, and if you don't feel a force that the particles are pushing back on you with, then you can't even tell that they're there. There's lots of examples of that. For example, there's a lot of neutrinos that pass right through your body all the time. There's a hundred billion neutrinos passed through your fingernail every second. You can't feel them, um, And they just zip right through and don't even notice you. And the reason is that they don't have any way to talk to you. So if you can't communicate with them, you can't. There's no way for you to push them or pull them, or for them to push your pull you. You can't even tell them they're You just walk right through them the way you walk through an empty room. So you're saying, we're sort of swimming in dark matter. Absolutely, we're almost drowning in it, because there's more dark matter than normal matter. So there's your room that you're sitting in has five times as much dark matter as it has air in it. For example, it's five of all the energy in the universe is normal stuff, and then something like is dark matter. So it's like, you know, one sixth of all the stuff that's in the universe, of all the matter that's in the universe, is what we used to call normal matter, and the rest of it is dark matter. And that's mind blowing to discover that what you thought was typical, we thought was normal, what you thought you know was the basic unit of the universe turns out to be a little extra bit. You know. It's like we've been eating the frosting and ignoring the cake, right, or we've been like focusing on the tail and ignoring the whole elephant. I have so many questions for you, but before we dive in, let's take a short break. So dark matter doesn't feel electromagnetism. And we know that because we know it's there, but we don't see it. Right, that's what we mean by see it and feel it. So that's what it's called dark right, It's you can't see it exactly that's just what we mean by dark that awesome marketing campaign of dark matter. That's the concept behind dark. Dark meaning we don't see it or feel it is right by it doesn't care. That's right. Yeah, But then you might wonder, like, well, if we can't interact with it at all, how could we possibly know it's there? Right? If you can't feel it or see it in any way, is it not just some fantasy some speculations, and like why should we care, Like if we can't see it or touch it, why why is it important to the universe? That's right? And so there is one way we can interact with dark matter, and that's through gravity. Dark matter is and that's the matter part of it, right, dark meaning we can't see it. Matter meaning it has stuff to it has gravity, and we know that it's a matter. We know it's made of something and it does have gravity. That's what matters is kind of defined as stuff that feels gravity and has mass. Yeah, exactly. That's what makes matter matter, is that it has some stuff to it, some mass to it, and anything that has mass to it is going to feel gravity. Okay, it's true that we can't feel or see dark matter because it doesn't have any electromagnetism, but it does have gravity, and so we can detect it. But because gravity is so weak, it takes enormous amounts of dark matter for us to notice. So kind of actually that there's so much dark Like even if there's a blob of dark matter right in front of me, I know I can't see it or touch it because it doesn't feel like your mignety forces. Um, but I know that you're telling me that I have like a gravity relationship with this blob, right, But it's super right. It's I don't even feel the gravity from this blob. There's definitely gravity between you and that room full of dark matter. Okay, And depending on what your math is, we don't have to say on that head. Yeah, even if you're a super massive guy who never left the house or massively cool, right or just massively funny and that's how weird, right, Like, um, like I have a gravity relationship with the error around me, have a gravity relationship with the like the microphone in front of me, with the table in front of me, with the car when I'm driving, But you just don't really feel that gravity relationship, right, That's right, You can't tell. It's drowned out by everything else in your life, and so you don't even notice. So you know, you can act like there's no gravitational force between you and the chair in front of you, because it's almost true. It's only like with the entire Earth that I feel that gravity relationship. Right, that's the one that pulls me down, That's right. And it takes a huge blob of stuff the size of the Earth for you to even notice. Okay, so dark matter is a different kind of matter. There's a ton of it in the years. It's all around this. We can't see it because it doesn't feel electromagnetic forces. We can't touch it also because of that um, but it does feel gravity. So how do we know that it was there? Like, how do we can't see or touch it? How do we how do we figure that? Yeah, it took people a while before they really accepted the dark matter was the thing. And it's a fun story because it's started with just a discrepancy. What they were doing was they were checking to see if they understood how galaxies spin. So our galaxy, you know, we are in a solar system, and a solar system is part of a big group of stars called the galaxy that all spins around. And our galaxy is called the Milky Way. And there's lots of galaxies in the universe, trillions more even more than that, probably, And we can look out into the sky and you can see other galaxies also spinning. And you can think of a galaxy sort of the way you think about like a America round. If you have a merriga round and you put a bunch of pink pong balls on it, you spin it, what's going to happen? The pink pun balls will fly off? Yeah, they'll shootout and hit your sister in the face. And then you get a diferent And those are some dark matters, and um, so what happens with the galaxy? Well, in the case of a galaxy, it's got a bunch of stars in it, and the galaxy is spinning. So why don't the ours get thrown out into intergalactic space all the time the way the ping pong balls might from Amerry around? Right, So galaxies are spinning their stars in it, why don't the stars just like spill out? That's right, I wanted they get tossed out? And the answer is gravity. The galaxy is a lot of gravity from all those stars in the black hole in the center and all that stuff, and that gravity holds the stars in place, like keeps everything in orbit. That's right, Yeah, it pulls it together and keeps stuff from getting thrown out. So some grad student went out to check this and they got a crazy result. And the result is that these galaxies are spinning way, way, way too fast. There's no way that the amount of stuff that we see in those galaxies is providing enough gravity to hold the galaxies together. Okay, something else had to be there, right, that's right, because the stars are not getting thrown into space, right, the galaxies are getting held together. So, as you know, first time, you have a crazy result. And there's a lot of explanations people come up with, and so the simplest explanation in some sense is, well, there's some kind of gravity that that's from something we can't see. So let's invent a new kind of stuff. It has to be dark because we can't see it. It has to be matter because it's giving us gravity. So we'll come up with a cool name for this new thing, called it dark matter. And that sounds like a simple explanation. But on the other hand, is not because there's not a tiny amount of stuff you have to add to these galaxies. Right, they're spending way too fast. And that's how we know that there's a ton of dark matter, because to get enough gravity to hold these galaxies together, you have to multiply the amount of stuff you can see by a factor of five. Tells you that, yeah, it tells you that what you see of the galaxy is not most of the galaxy. You know, you're looking at the galactic tonails, or you know they're just the galactic fingertips or something. Most of the galaxy is something else, right, right, the milky toes of these and and so for a long time people didn't accept that, and there were other ideas. People thought, well, that's crazy because you can't just say, oh, my experiment didn't work. Maybe the universe is filled with there's a new kind of stuff that nobody's ever seen before, and there's a huge amount of it and it's everywhere. Right, it's sort of a convenient and crazy explanations. Remever, in science, we like simple explanations, right. We want the simplest set of ideas to explain everything. We see so that was yeah, so that was that was that was the mindset, right. I was like, Okay, we know, we think we know the universe. Let's check to see if the galaxies are spinning as they should. But they found out they're spinning too fast. And the only explanation someone could come up with was like, may there's invisible gravity stuff in these galaxies that's like five times eavery than all of those stars. That's right, That was the idea of dark matter. There actually were other explanations that lived for a little while, and recently they died because they they were ruled up by other experiments. Since then, we're pretty sure that dark matter is a thing. And one way that we were able to figure out that dark matter is there and it's not just a misunderstanding of the way gravity works, is that we found a few other ways to spot it. So they're all they're almost all gravitational, but there are other ways to spot it to tell us that would give different results if it was actually dark matter or this other weird kind of theory about gravity. And I want to talk about that some more, but first let's take a quick break. So one way, it's called gravitational lensing, and that's when dark matter in the sky bends the light and gives these crazy optical effects. And that's one way we can tell where dark matter is. It's in a blob here, it's in a blob there makes these cool distortions in the sky because it has gravity, and it's like not just pulls the stars and planets around it, but it also bends light around it, because we know that's what gravity does, right, Yeah, because that's what matter does. Matter, All matter has gravity, and dark matter can bend the space because it has gravity, so it acts like a cosmic lens in the sky. It's totally mind blowing and everybody out there should google gravitational lensing and see those those images because they're gorgeous. And then the other way that we know that it's definitely there through gravity is um, what, what's the other thing? Yeah? The other thing was this amazing event that happened very far away, a long long time ago when two clusters of galaxies smashed into each other. And what every every cluster of God sees has both normal matter like me and you and gas and stuff and dust and also dark matter. So when they smash into each other, the normal matter smashes and creates explosions and gives off light, and we can see that. But the dark matter passed right through to the other side, so you can and we can see the dark matter there because of the gravitational lensing, so that dark matter got separated from some of the normal matter, and we can see its gravitational effects on its own And that was the key to knowing that dark matter really is its own thing with its own gravity. It's not just the misunderstanding of the way gravity works, right, because if that were the case, you wouldn't be able to separate this new new gravity from the old gravity. But because you can, because you can say, oh, here's this dark matter separated from all that gas in the dust. We can see it has its own gravity. It must be its own thing. So that tells us there's a lot of dark matter. It's out there. We can see it kind of through gravity, even not directly, but doesn't really tell us that much more about dark matter. Why if is this care about dark matter? Like, why is it? Why is it important? Why is it cool? And interesting? What? We want to make awesome sunglasses? That's the number one goal. How would you make dark matters sunglasses, that would be pretty pretty easy. Yeah, well matter for sure. No, it just comes out of a desire to understand. You know, we look at the world around us. We want to know how does this all put together? You know, what is the principle that organizes this um And part of it is a desire to build new kinds of stuff. I mean, if you understand the world around you, then you know how to manipulate it and use it and build transistors and all sorts of cool stuff. So there's thousands of applications as soon as you understand how matter works. But there's also just that core curiosity. We're like, you know, five dots away from being able to connect dark matter with anything specifically that's useful. But every time we found something new about the universe, some surprise, something crazy, something new, it's always led to, you know, economic revolutions, or technological revolutions, or even just intellectual revolutions. I mean, if you find out that the universe works in a way different from what you expected, it changes the way you think about your life and the whole human experience. I mean it's not just a little bit. It's like we're we're the minority in the universe, you know, not been We're not even the center of gravity of the universe by any means, right, that's right. If there was an election, we would definitely not any representatives. But yeah, that's that that's wild to know, right, Like, we're not the most kind of stuff in the universe. And so that's that's why dark matter is important. It's like, that's that's the bigger chunk of the universe, and so it kind of affects the way we know how things happen. Yeah, and it's responsible for the basic structure of the universe. We've done simulations. For example, we say, what would the universe look like if there hadn't been any dark matter? Right, run those stimulations forward and fourteen billion years in, you don't have any galaxies really, And the reason is that, yeah, you don't have dark matter pulling together normal matter and compressing it. No, we wouldn't be here at all. The universe would be much more diffuse and boring. We wouldn't have any podcasts at all. That's not to say like dark matter is the reason for creation or is more important than us. I mean, we don't really know what it is at all. It could be totally boring and sterile and just a bunch of little particles that are kind of aloof and ignore us, all right. It could be something more interesting though, So dark matter it's a different kind of of stuff of matter than us. We're made out of quarks and electrons um. Dark matters maybe made it out of something different that um. It's not quite the same thing as we were made out of, right, And it could be particles. It could not be particles. It could be um stuff. It could be some new kind of stuff how other stuff works. So it's different than us. There's a ton of it in the universe. There's five times more dark matter than regular matter. And it's all around us. It's like it's it's almost on top of us, you know, we're in it, and it's inside us. It's everywhere and passing through us. And you're waving your arms through right now. I feel that dark matter, Yeah, I feel it. It's it's inside of you. It's been inside of you all along. Well that sounds a little in appropriate. No, it's like a like courage, you know, it's like cark ridge or or wisdom, summon the dark matter within you sort of thing. Yeah, Okay, it could be like complex stuff, right, dark matter could be interesting and complex and have different kinds of properties to it. Right, that's right, because there could be other checkboxes we talked about, you know, the strong and the weak force, and electromagnetism and gravity. Those are the four forces we know, but there could be a fifth force that only dark matter feels. And it feels it with itself. It's easy to say, well, the simplest idea is dark matter is all just one particle. And that's simple idea, and we like to start with simple ideas to mapically work versus just like a weird homogenous blog. Yeah, but you know, look at the five percent in the universe we've studied. It's not just one kind of particle. It's a bunch of different kind of particles, and it's complicated and interesting. So there's no real reason to expect that dark matter is different. It could be even more complicated. And that's and that's assuming Remember that dark matter is a particle. We have actually no evidence whatsoever proving that dark matter is a particle. Of the normal matter we've ever seen is made out of particles, And that's the assumption we're using to say, well, probably dark matters also made out of particles. That's like saying I've only ever seen the tail of the elephants, so the rest of the elephant must also be tails, right card, It's all tales all the way down. It sort of falls apart, and it's a good way to start, you know. But I'm hoping that we discover the dark matter is something else, insing, weird, some different kind of matters just sort of expands our minds out of our current way of thinking into some new direction where we consider possibilities we hadn't even considered before. Do you have a question you wish we would cover, Send it to us. We'd love to hear from you. You can find us on Facebook, Twitter, and Instagram at Daniel and Jorge one Word, or email us to feedback at Daniel and Jorge dot com. N