Speaker 1: Welcome to Stuff you Should Know from how Stuff Works
Speaker 1: dot com. Hey you, welcome to the podcast. I'm Josh Clark,
Speaker 1: and there's Charles w. Chuck, Bryan, there's Jerry, and um,
Speaker 1: we're about to try some physics. Oh yeah, this is
Speaker 1: stuff you should know. We're about to try some food. Yeah,
Speaker 1: this did not break my brain like I thought it would. Yeah.
Speaker 1: I think it's a pretty surface level explanation, but like
Speaker 1: it gets the point across, and I don't see any
Speaker 1: reason for us to try to go any deeper. I
Speaker 1: think we're very quickly spin out of control, like a
Speaker 1: up down cork or something. Yeah. So dark matter is
Speaker 1: invisible glue that holds everything together the end, the end.
Speaker 1: We just don't know what it is. No, we'll get
Speaker 1: into it, but you might notice, dear listener, a new
Speaker 1: thing in your feed popping up next week next week,
Speaker 1: next Wednesday, Wednesday, Wednesday Wednesdays. We are debuting a new
Speaker 1: thing called short stuff, which is just the cutest name
Speaker 1: it is. It's stuff you should know. Short Stuff, I
Speaker 1: guess is the full name probably or not, who cares,
Speaker 1: but it's just it's a stuff you should know episode.
Speaker 1: It's you, Me and Jerry but over the years of
Speaker 1: of recording, like we've got these lists of topics we
Speaker 1: want to do, and this one, like part of the
Speaker 1: list is kept getting bigger and bigger and bigger because
Speaker 1: they're like topics out there that are really interesting, but
Speaker 1: they're just not big enough for a full episode, even
Speaker 1: with Tangent upon Tangent, And we could have, like we
Speaker 1: could have been like, well, we'll put like three of
Speaker 1: them together randomly. We thought about doing that one. It
Speaker 1: just didn't feel right. So what we did was spin
Speaker 1: off like a new podcast called short Stuff, which is
Speaker 1: just a smaller sized episode of stuff you should know.
Speaker 1: Just because the topic wasn't quite big enough to warn
Speaker 1: a full episode or a large size episode, we're doing
Speaker 1: a small size episode. Yeah, so look for like ten
Speaker 1: to fifteen minutes tops. I think we're in the wheelhouse
Speaker 1: of about twelve minutes. We seem to like magically hit
Speaker 1: twelve every time. Yeah, and it's like it's kind of fun.
Speaker 1: I think it's it's a great idea. I'm really happy
Speaker 1: with him. Yeah, same here. And I think the first
Speaker 1: four we recorded, we didn't know what we're gonna call
Speaker 1: it yet, And I don't believe we went to the
Speaker 1: trouble of going back and changing that. Are we gonna
Speaker 1: we might do that? Are we doing that? Jerry? She
Speaker 1: just shrugged. No, she said, now, she said, that sounds
Speaker 1: like a lot of work. Yeah, it would be just
Speaker 1: like us to just sort of waddle our way into
Speaker 1: this thing, and which is exactly what we did. But
Speaker 1: hopefully you guys enjoy them. It didn't cost you anything. Um,
Speaker 1: so don't complain. Actually do complain if they're way off
Speaker 1: base or they could be better. We want to hear
Speaker 1: about it. No, I think people will be like, oh,
Speaker 1: this is just like a little bite size stuff you
Speaker 1: should know. So that's exactly what it is. It's like
Speaker 1: a Snicker's miniature, but of stuff you should know. That's right,
Speaker 1: And you know our love of small things here, especially
Speaker 1: Snickers or like tiny Tabasco bottles. This is the tiny
Speaker 1: Tabasco bottle version of over show. Those things are priceless,
Speaker 1: all right, So physics dark matter go, let's do this,
Speaker 1: all right? So this wasn't as hard as I thought. No,
Speaker 1: and it's actually pretty easy to get across. Here's the thing.
Speaker 1: So astronomers have gotten to the point it's starting in
Speaker 1: about on astronomers and physicists and astrophysicists and even particle
Speaker 1: physicists guys to the point where all of their combined
Speaker 1: knowledge was refined enough that they could look out into
Speaker 1: the universe and be like, we can figure out how
Speaker 1: much this ways, to put it more scientifically, we can
Speaker 1: figure out what the mass of the universe is. It's
Speaker 1: going to take us a really long time, but we
Speaker 1: are now at the point where our level of observation
Speaker 1: and our level of understanding of physics is such that
Speaker 1: we can do it. We're there now. Yeah, And it's
Speaker 1: not just like, oh, well that weighs this the end,
Speaker 1: Like knowing something's mass tells you a lot about it,
Speaker 1: the way it behaves and the nature and future of
Speaker 1: the universes we'll see, yeah for sure. So it's not
Speaker 1: just weight, it's it's more complicated than that, and what
Speaker 1: weight can tell us, right. The problem is that you
Speaker 1: can't just like put a galaxy or star or something
Speaker 1: on the scale. They have to broke the scale pretty quick. Uh,
Speaker 1: it actually vaporized it. But the the there are ways
Speaker 1: you can infer the mass of something. Yeah. Um. One
Speaker 1: of the ways that you can infer the mass of
Speaker 1: a star from what I understand is to measure it's luminosity,
Speaker 1: how bright it is. Yeah, I've also heard that's a
Speaker 1: mixed bag because they have different um different sizes in
Speaker 1: their lifespan. Um, I've just heard luminosity and mass is
Speaker 1: not is not just straightforward like like most things in
Speaker 1: astro physics are. Yeah, that's the word on the street right. So. Um.
Speaker 1: When they started getting to the point where where they
Speaker 1: could infer the weight of a star, or of a
Speaker 1: galaxy or of a galaxy cluster, which is basically like
Speaker 1: a galaxy of galaxies, they started to notice something really weird.
Speaker 1: All of the matter that they could see, the stars,
Speaker 1: the gas clouds, the cosmic dust, the everything, matter, things
Speaker 1: that make up you and me, things that everything has
Speaker 1: a common basic unit and atom that's made up of
Speaker 1: elementary particles like protons and neutrons and electrons. Matter, Every
Speaker 1: non living and living thing on in the galaxy you
Speaker 1: would think is made of matter. The problem is is
Speaker 1: they started finding that, you know, this galaxy over here,
Speaker 1: in this galaxy cluster and everywhere we're looking, the amount
Speaker 1: of matter that we're seeing is way too small for
Speaker 1: the amount of mass that the thing we're looking at
Speaker 1: appears to have and a cosmological mystery was launched. What
Speaker 1: the heck is going on? Was the question of the day. Yeah,
Speaker 1: so all that matter that we know about, they call
Speaker 1: that barrionic matter. Uh. And they were like this, the
Speaker 1: calculations are off or something like, there's got to be
Speaker 1: something else there to account for this. Well, that's the
Speaker 1: to the two possibilities. Well. Uh, and so way back
Speaker 1: in uh geez was at nineteen thirty two an astronomer,
Speaker 1: a Dutch astronomer named Jan hendrik Ert because he's Dutch,
Speaker 1: he actually I believe was the first person to use
Speaker 1: the term dark matter. Is that right? That's what I saw?
Speaker 1: So dark matter is a is a sort of a
Speaker 1: placeholder name for what they came up with for this,
Speaker 1: for lack of a better word, this invisible uh matter
Speaker 1: that has to be out there is it's sort of
Speaker 1: like wind, Like you can't see wind, but that doesn't
Speaker 1: mean it's not out there because you can measure it
Speaker 1: in different ways, see how it reacts on other things.
Speaker 1: And so they called started calling it dark matter. This
Speaker 1: in sable. Well we'll talk about what it ends up
Speaker 1: sort of looking like in a minute. I want give
Speaker 1: that away yet. But this invisible matter that they think
Speaker 1: is there, right, but it doesn't. It doesn't emit or
Speaker 1: absorb light or electromagnetic magnetic energy. So it's it's way different.
Speaker 1: It behaves differently such that people were very confused as
Speaker 1: to what the heck was going on, and they still are. Yeah. Sure,
Speaker 1: So there's so this term dark matter, like you said,
Speaker 1: it's a placeholder, and it's a placeholder for the current
Speaker 1: point we are in our understanding of the universe, which
Speaker 1: is when we look out at galaxy clusters and galaxies
Speaker 1: and all this stuff, there's not enough matter to account
Speaker 1: for the amount of mass that we're seeing. So again,
Speaker 1: that means one of two things. Either there's something there
Speaker 1: that we can't detect, or our our understanding of physics
Speaker 1: is off, and the term dark matter stands for both
Speaker 1: of those. It could be a thing, an underscovered particle
Speaker 1: or something like that, or it could be a misunderstanding
Speaker 1: of physics that we need to eventually correct. Either way,
Speaker 1: there's a lot of mass that is unaccounted for throughout
Speaker 1: the universe, and it seems like there's a lot more
Speaker 1: what we call dark matter then there's regular matter. And
Speaker 1: the more we look into it, the more it seems
Speaker 1: like there's something there that we haven't discovered yet. Yeah.
Speaker 1: So right now, barrionic matter, all the stuff that we
Speaker 1: know about counts for about four and a half percent. Uh,
Speaker 1: where they peg dark matter. Then we have something that
Speaker 1: I don't even know if I ever want to cover,
Speaker 1: called dark energy, which makes up the other SEV. But
Speaker 1: they know it's there because there's something out there that
Speaker 1: we can account for that has a significant gravitational force. Right,
Speaker 1: that's where the whole the whole thing started where they
Speaker 1: first detected it. Right, so, um, when they first started
Speaker 1: looking out at galaxies and stuff like that. There's this
Speaker 1: whole thing that Newton came up with the second law
Speaker 1: of motion where and this is like a tried and
Speaker 1: true law. It's a law. This isn't Newton's suggestion of
Speaker 1: motion or Newton's second what about this of motion? It's
Speaker 1: a scientific law. That's how that's has proven and accepted
Speaker 1: as a scientific observation can be is to be made
Speaker 1: a law. And it said that when you're looking at
Speaker 1: a galaxy far far away, and the most of the
Speaker 1: matter is accumulated towards the center of the galaxy, then
Speaker 1: that means most of the mass is accumulated towards the center. Okay, yes, okay,
Speaker 1: So that means that the stars near the center are
Speaker 1: going to spin. They're going to rotate around the galaxy
Speaker 1: a lot faster than the ones on the fringes, because
Speaker 1: the ones on the fringes are going to go a
Speaker 1: lot more slowly because they're further away from that center
Speaker 1: of mass. So the gravitational pull is going to be weaker. Yeah,
Speaker 1: I mean, that's the easy ist way to say it
Speaker 1: is in the center, you have more mass. More mass
Speaker 1: means things are spinning faster, there's more gravitational pull. So
Speaker 1: all the astronomers supposed, like you said, the stuff on
Speaker 1: the outskirts are probably hanging out there spinning a lot slower, right. Well,
Speaker 1: when they looked, they found that's not the case at all.
Speaker 1: As a matter of fact, the stars on the outside
Speaker 1: are spinning around the center of the galaxy just as
Speaker 1: fast as the stars near the center of the galaxy,
Speaker 1: which makes zero sense. Yeah, it's almost as if there's
Speaker 1: some invisible force out there, right Like if you look
Speaker 1: at this, if you look at this um this galaxy.
Speaker 1: The situation that they started to find and it wasn't
Speaker 1: just one galaxy. They found it in this galaxy too,
Speaker 1: in this galaxy too, and even stranger than that, they
Speaker 1: found it in those clusters, those galactic clusters. So rather
Speaker 1: than stars that make up a galaxy, this is galaxies
Speaker 1: making up a huge, giant mega galaxy. The same thing
Speaker 1: happened the galaxies on the outer edge of the cluster.
Speaker 1: We're circling just as fast as the ones towards the center,
Speaker 1: and it just must have knocked their socks off. I
Speaker 1: can't imagine how many times they went over the same
Speaker 1: thing to make sure that they had gotten it. This
Speaker 1: is for uh clarity. This was the nineteen fifties and
Speaker 1: nineteen sixties when the yeah, okay, so what they figured
Speaker 1: out was that either there was something really wrong or
Speaker 1: there was something that they hadn't picked up yet. Because
Speaker 1: those stars on the outer edges of the galaxy, or
Speaker 1: those galaxies on the outer edges of the cluster, for
Speaker 1: as fast as they were flying they should have spun
Speaker 1: off into space. There was something missing that explained what
Speaker 1: was holding that galaxy or that cluster together as fast
Speaker 1: as the stars of the galaxies were spinning around on
Speaker 1: the outside. That was the first clue that something was
Speaker 1: way up with that, that that that astronomy was missing
Speaker 1: something big, right, And they knew this was off because
Speaker 1: they had been using luminosity, like you said, to take
Speaker 1: measurements for years and it was pretty good. But then
Speaker 1: when they started, uh, measuring the rotational velocity of things,
Speaker 1: like how fast something was spinning in relation to where
Speaker 1: it was like towards the center, it, like you said,
Speaker 1: there was a missing ingredient there that didn't match whatever
Speaker 1: these luminosity readings were showing. So you're right, luminosity was
Speaker 1: clue one. The um angular rotation was or acceleration of
Speaker 1: the outer stars was clue number two. So now we've
Speaker 1: got to two different ways of measuring the mass and
Speaker 1: gravity of remote bodies in the universe, and they don't
Speaker 1: align our point. Well, they're they're aligning in that there's
Speaker 1: something missing here um. And I think that's a pretty
Speaker 1: good cliffhanger for a breakdown too. I think people are
Speaker 1: going to be like, what, Yeah, well, why don't you
Speaker 1: guys go listen to the first half of this podcast
Speaker 1: or first part again and we'll see you after these messages.
Speaker 1: I really hope we're putting this like well, I feel
Speaker 1: like we are, but sometimes you know, you just can't tell. Now,
Speaker 1: this isn't the sun re ducks. Oh god, no, no, no,
Speaker 1: this is much more simple. So, uh, like you said,
Speaker 1: they not only studied regular galaxies, but they started to
Speaker 1: study what what you referred to as and you didn't
Speaker 1: make it up, but galactic clusters. These knots of galaxies
Speaker 1: could be thousands of them, could be hundreds of them,
Speaker 1: but they were bound together by gravity. And they were like,
Speaker 1: you know what, let's study these because maybe what we
Speaker 1: can find or you know, this is what we suppose
Speaker 1: at least, is there might be be these big giant
Speaker 1: pools of hot gas that we never could detect before
Speaker 1: and that would account for all of this mass. And
Speaker 1: they did find these superheated gas clouds and we're like, great,
Speaker 1: that's it. But they're like, it still doesn't account for everything.
Speaker 1: That's like a small percentage of of the of what's
Speaker 1: what is needs to be accounted for. Right, So it
Speaker 1: was a it was a breakthrough, but it wasn't the
Speaker 1: solution solver that they were looking for. It was because
Speaker 1: so if you can find, um, you know, something that
Speaker 1: we know has mass, like huge clouds of gas. That again,
Speaker 1: you know, particle has mass, and if you put enough
Speaker 1: particles together, it has a lot of mass. If you
Speaker 1: could fill in the blanks of the missing matter, um,
Speaker 1: that explains the mass of this thing you're looking at, great,
Speaker 1: especially if it's something we already know about, like hot gas.
Speaker 1: And they did find some hot guests. But say that
Speaker 1: that explained five of the missing of the missing mass.
Speaker 1: It didn't explain everything. And what that did do also was, Okay,
Speaker 1: we've gotten that much more sophisticated and it still hasn't
Speaker 1: answered this dark matter thing. It's pointing to the idea
Speaker 1: that there's something we haven't discovered yet that is accounting
Speaker 1: for all of this. It's very foreboding, it is, but
Speaker 1: it's also I think very exciting. Sure yeah, yeah for them,
Speaker 1: uh and us. So the other thing that happened when
Speaker 1: they started studying these galactic clusters was that they found
Speaker 1: out that these clusters and superclusters can and this is
Speaker 1: really neat. You can look up images of this. It
Speaker 1: can distort space time because their mass is so great.
Speaker 1: So if you're on planet Earth, uh, and there is
Speaker 1: a light so you're looking from like a telescope on Earth,
Speaker 1: you're looking at a distant light, like who knows how
Speaker 1: far away, like a star three billion light years away?
Speaker 1: Sounds great. In between mean you and that is a
Speaker 1: galactic cluster. Let's say that will just that will act
Speaker 1: as a lens, and depending on where it's situated to
Speaker 1: where you are relative on Earth, it will distort that
Speaker 1: light uh into one of several things. If you're in
Speaker 1: perfect alignment in it, uh, it's gonna form what's known
Speaker 1: as an Einstein ring. And if you look it up
Speaker 1: on the internet, it's like this beautiful like circle of light. Yeah,
Speaker 1: it's really cool looking. Uh. It could be elliptical or oblong.
Speaker 1: They call it the Einstein cross basically splits it into
Speaker 1: four so it just looks like four little stars, all
Speaker 1: like perfectly lined four copies of the same image. Yeah, yeah,
Speaker 1: and like a cross, yeah, perfect cross. Or it could
Speaker 1: be a cluster. And this one is sort of cool
Speaker 1: just because it's like kind of scattered. It looks like
Speaker 1: a bunch of like arcs and banana shaped arcs and arklets.
Speaker 1: But it's all different versions of the same image that
Speaker 1: we're seeing. And what you're seeing is that far away star,
Speaker 1: but you're seeing it through that galaxy cluster that is
Speaker 1: a distortion of spacetime that the the mass of these
Speaker 1: clusters are so big and so huge that the gravity
Speaker 1: in them bends light, just like a mound of glass
Speaker 1: can bend light. Same thing. Now we've gotten to the
Speaker 1: point where we are so good at math and physics
Speaker 1: that we can look at that reflection that bend and
Speaker 1: say this, this galaxy has that much gravity, and since
Speaker 1: this galaxy um has this much gravity, it must have
Speaker 1: this much mass. Now if you take that number, this
Speaker 1: much mass, and you examine the luminosity of the galaxy, yeah,
Speaker 1: you're like, this is like not off by you know,
Speaker 1: like the luminosity is ten, but the mass is ten
Speaker 1: and a half. There's like factors sometimes factors of of
Speaker 1: like times a hundred. Sometimes like there's just no way
Speaker 1: that your math is off. It's it's there's a huge discrepancy.
Speaker 1: So there's a third clue that there's something missing. Yeah,
Speaker 1: I mean that's basically all these are are little hints
Speaker 1: along the way that we're still not able to account
Speaker 1: for something with our calculation. Yeah, and rather than the
Speaker 1: better and more sophisticated our observations and exploration of space
Speaker 1: in the universe becomes it doesn't become like this. This
Speaker 1: blank is not getting filled in. It's just becoming clear
Speaker 1: and clear that that blank is there. Yeah, exactly, there's
Speaker 1: a void in either our understanding or our discovery. So
Speaker 1: then computers started getting better and better and more advanced.
Speaker 1: I love how this, uh this article puts it. They
Speaker 1: turned to the computer. It sounds like they turned to
Speaker 1: the bottle or something to compute. Uh. So computer started
Speaker 1: getting so good, and our knowledge of what was out
Speaker 1: there and our measurements of matter and mass was so
Speaker 1: great that we could take a pretty good guess on
Speaker 1: how much baryonic matter there was out there, maybe how
Speaker 1: much dark matter there might be. Design a program and
Speaker 1: a model that you could feed this information into to
Speaker 1: spit out what it might quote look like end quote. Yeah.
Speaker 1: They basically said, this is how much barionic matter we
Speaker 1: think there's. This is how much dark matter we think
Speaker 1: there is. Go computer, and they hit start on the
Speaker 1: Whopper machine, and it spit out what was sort of
Speaker 1: like a It turns out that it wasn't on the edges.
Speaker 1: It was everywhere. It was like a web that wound
Speaker 1: through everything invisible to us. That sort of acted like
Speaker 1: this cosmic glue. Yeah, and so in some places it clumped.
Speaker 1: In other places there were long filaments and it kind
Speaker 1: of looked like it had galaxies or galactic clusters trapped
Speaker 1: in a spider's web. But it just permeated everywhere. And
Speaker 1: like you said, it seemed to be like this cosmic
Speaker 1: glue or cosmic connective tissue um, and it was pretty
Speaker 1: so prizing. So they said, okay, well that's that's the
Speaker 1: computers take see if we can replicate that. And that
Speaker 1: kicked off a series of projects that are still going
Speaker 1: on today to map dark matter in the universe, which
Speaker 1: I want everybody to stop for a second, because this
Speaker 1: is about as nuts as it gets. They have gotten
Speaker 1: to the level of sophistication where astrophysicists are mapping in
Speaker 1: three D models stuff that isn't there. They're mapping three
Speaker 1: D models avoids based on how how much light bends
Speaker 1: around a galaxy three billion miles light years away light
Speaker 1: years right, and then using that to infer the gravity
Speaker 1: and then the mass, and then they're using that information
Speaker 1: to create a three D map of something that may
Speaker 1: not exist. And the coolest thing about all this to
Speaker 1: me is it's based on stuff that Isaac Newton and
Speaker 1: Einstein came up with, and well, well we won't spoil it,
Speaker 1: but they weren't wrong. But that is nuts. This is
Speaker 1: either either physics has gone totally insane, yeah, or this
Speaker 1: is the pinnacle of human ingenuity. Thus far, well, thus
Speaker 1: far for sure. I'm glad you added that. So let's
Speaker 1: talk about a couple of these. About seven years ago,
Speaker 1: in two thousand and eleven, there were a couple of
Speaker 1: teams using data from uh Schandra's X ray observatory. And
Speaker 1: what they're trying to do here, like you said, is
Speaker 1: take these create this real map based on direct observation
Speaker 1: instead of this speculative computer map. What they found out
Speaker 1: is the computer map was pretty on, which was great, um,
Speaker 1: but they needed the real things. So they are looking
Speaker 1: at a cluster or have been called a bell three
Speaker 1: three two point three billion light years from Earth, and
Speaker 1: what they saw was what looks like sort of a
Speaker 1: football and American football, we're a n Ausi football for
Speaker 1: that matter. Are they similar? I just got one in
Speaker 1: the mail. I bought one. You need to get Simon
Speaker 1: to sign it, go Melbourne. I should, but it would
Speaker 1: coust so much to ship it there and back maybe
Speaker 1: able to see Simon again one day. Is Melbourne your team? Now? Yeah,
Speaker 1: that's what I got on. That's that's a good city. Yeah.
Speaker 1: I like it so. Uh it looks like a football
Speaker 1: with one end pointing towards us or you know, we're
Speaker 1: we're on Earth, so we're the observer in this case.
Speaker 1: And uh they Here's the one thing they didn't agree
Speaker 1: on though, was the density of the dark matter on
Speaker 1: able three in the center. Yeah, which is weird because
Speaker 1: some people calculated it was more dense in the center
Speaker 1: and matter increase, and other people said it was the opposite,
Speaker 1: not like, well, we're not sure, but they thought it
Speaker 1: was uh less dark matter at the center, which is
Speaker 1: a big deal. But they yes, but they both came
Speaker 1: up with virtually the same shape and same orientation. Yeah,
Speaker 1: separately and independently, which showed we're onto something or else. Again,
Speaker 1: we're all collectively out of our minds based on some
Speaker 1: shared delusion that we're all working under. Right. Then there
Speaker 1: was another one. This one is super cool. Uh in
Speaker 1: January two thousand twelve. Uh, anytime I see international team
Speaker 1: of researchers, I get excited. But the Canada, France Hawaii
Speaker 1: telescope has a three forty megapixel camera, so you can
Speaker 1: actually take pictures of stuff that far away. It's like
Speaker 1: the iPhone Excess camera. Is that one of the new ones? Yeah? Okay,
Speaker 1: is it good. I think it's pretty good camera. It's
Speaker 1: not three forty megapixel. No, it's not. I have to
Speaker 1: say I've been to this observatory before. Oh really, it's
Speaker 1: really cool. Did you look at like the photos on
Speaker 1: display and stuff. No? No, they had like telescopes that
Speaker 1: you walked around and looked out into the universe and
Speaker 1: it's amazing. Did they let you take pictures? Uh? Yeah,
Speaker 1: I guess so with your phone? Oh I thought you meant,
Speaker 1: I mean with the me I'm probably. I'm sure they
Speaker 1: were taking picture the US or anything. But what's crazy
Speaker 1: is it's on Hawaii, so it's just hot and muggy
Speaker 1: and humid, and then you drive up this mountain and
Speaker 1: you're like freezing in another face coat with like a
Speaker 1: hat on, and then you just go back down the
Speaker 1: mountain and in Hawaii. Again, it's very very cool experience.
Speaker 1: So what they did here was basically stitched all these
Speaker 1: photos together. It was like photos of ten million galaxies
Speaker 1: and four different regions over five years, stitched it all together,
Speaker 1: and what they finished up with was basically saying that
Speaker 1: computer model was pretty on target because what this looks
Speaker 1: like is what it's spit out so many years ago. Yeah,
Speaker 1: so they're they're they're definitely onto something. It seems like,
Speaker 1: should we take another break? Yes, all right, we'll talk
Speaker 1: about what dark matter is. Hint, we don't know. Alright, Chuck,
Speaker 1: we're back, which is where I start to get a
Speaker 1: little like brain breaking. I understood all that stuff, but
Speaker 1: this stuff is where I was like, what, well, we're
Speaker 1: transferring from astrophysics to particle physics. Maybe that's my hang up,
Speaker 1: And particle physics is hard. I actually had to teach
Speaker 1: myself particle physics to UM write one episode of UM
Speaker 1: The End of the World. Maybe that's my problem. It's
Speaker 1: it's and even still I'm like, wait, what there's it's
Speaker 1: really hard to understand. Yeah, I've always been an astrophysicist,
Speaker 1: though at heart I think so that's just goes against
Speaker 1: my nature. Okay, I'm with you. But they're they're very
Speaker 1: much tied together, like you need particle physics to explain
Speaker 1: these larger cosmic structures, right, So the big question here
Speaker 1: is at the end of the day, Uh, is it
Speaker 1: the fact that we just can't really observe this stuff
Speaker 1: and it's just like all the other matter, or is
Speaker 1: it some new matter that we don't even know about yet.
Speaker 1: That's the question, that's the big question. Or the third
Speaker 1: option is that our physics are understanding of physics is wrong, right,
Speaker 1: which means, well, we'll see some people go back in
Speaker 1: tamper with things. Newton said he didn't like that much
Speaker 1: to the dismay of brain. So, um, if if it's
Speaker 1: just stuff that we already know exists but we just
Speaker 1: can't observe yet, those fall under the umbrella of Macho's
Speaker 1: massive compact halo objects, which are huge massive structures that
Speaker 1: we already know about Neutron stars, black holes, round dwarf
Speaker 1: stars that are huge massive it have a tremendous amount
Speaker 1: of mass and thus exert a lot of gravity around them, um,
Speaker 1: but are too dim to show up clearly when we're
Speaker 1: looking at say a galaxy or galactic cluster. Yeah, like
Speaker 1: we talked about luminositi, they have low luminosity. We know
Speaker 1: they're there, but they're not shining, But we don't know
Speaker 1: that that's them. That is one proposal for what dark
Speaker 1: matter is. They're just things that we already have identified.
Speaker 1: No exists, we just can't see them in these particular things.
Speaker 1: That's actually doesn't have for as as Acam's razory as
Speaker 1: that is, that actually does not have as much support
Speaker 1: in the physics community as the other idea that that
Speaker 1: dark matter is made up of some particle that we
Speaker 1: have not discovered yet. Yeah, so that's where I got
Speaker 1: a little confused with the whimps and the scimpse. WHIMPS
Speaker 1: stands for weakly interacting massive particles, uh, huge amounts of mass,
Speaker 1: but difficult to detect because they just interact weekly with
Speaker 1: ordinary manner. Right, Here's why they're difficult to attack. To
Speaker 1: detect that they interact weekly with matter. That's not stating
Speaker 1: it very well. There's the weak nuclear force is one
Speaker 1: of the four fundamental forces, and it's found almost exclusively
Speaker 1: in the nucleus of an atom. What what these WIMP
Speaker 1: particles weak interactive um massive particles are. They're hypothetical. We
Speaker 1: don't know that they exist. Mathematically, they fit the bill
Speaker 1: of dark matter um the fact that they interact with
Speaker 1: gravity and with the weak force only means that, no,
Speaker 1: we can't detect them. We don't have weak force detectors.
Speaker 1: We have detectors along the electromagnetic spectrum. So everything we
Speaker 1: do when we look out in the universe, we use
Speaker 1: X rays or microwaves or radio waves, all of those
Speaker 1: are electromagnetic. If these particles don't interact with the electromagnetic force,
Speaker 1: that has no effect on them whatsoever. We have no
Speaker 1: way of detecting them. All we can do is since
Speaker 1: they have a gravitational pull, because they have so much mass,
Speaker 1: we can just sense their gravity and be like, what
Speaker 1: the heck is going on? Which is exactly the position
Speaker 1: we're in now. Whimps were a big um They were
Speaker 1: promoted as as the particle I think starting in the
Speaker 1: eighties because there does because there was something called the
Speaker 1: whimp miracle. And this breaks my brain. But apparently if
Speaker 1: you take the the relic density, which is really unimportant
Speaker 1: for getting into here, but say the density of a whimp,
Speaker 1: like how how dense the universe would have to be
Speaker 1: for a whimp to exist, it corresponds with the weak
Speaker 1: um force number. And that made everybody say, oh, well,
Speaker 1: they're particles that don't interact with the elect a magnetic force,
Speaker 1: they disinteract with the weak force. Nowadays they've kind of
Speaker 1: moved to the strong nuclear force simps. And the strong
Speaker 1: nuclear force also has found just basically in the nucleus
Speaker 1: of an atom. It's the thing that holds an atom
Speaker 1: together super tightly, holds the corks into the proton and
Speaker 1: hold the holds the proton and the and the um
Speaker 1: the what's the what's the neutral charge one neutron. Yeah,
Speaker 1: the neutron and the proton together and keeps them together.
Speaker 1: That's the strong nuclear force. And they think that that
Speaker 1: that is probably the particle. Now so the same thing
Speaker 1: though doesn't interact with the electro magnetic spectrum, so we
Speaker 1: have no way of detecting it, but it would still
Speaker 1: have mass and hence exert a lot of gravity. So
Speaker 1: that's sort of the takeaway, right. Well, not everyone is
Speaker 1: on board with this UH period, Like some people, there
Speaker 1: are some astronomers out there who say they dare say
Speaker 1: maybe Newton got it wrong and maybe we should crack
Speaker 1: open the Bible and rewrite it, like Thomas Jefferson and UH.
Speaker 1: In the eighties, there was a dude physicist name Mordecaig
Speaker 1: mill Grom. He suggested that Newton's second law of motion,
Speaker 1: which is force equals mass times acceleration, which I got
Speaker 1: wrong in the board breaking episode. That's right, but we're
Speaker 1: not physicist. We just played them on the air. Uh.
Speaker 1: He said, maybe we should look at that again and
Speaker 1: maybe he was wrong, and maybe we should modify this.
Speaker 1: And he called this modification mind modified Newton Newtonian dynamics.
Speaker 1: And Uh, the way that I read this was it
Speaker 1: almost sounded like it's probably not quite right, but almost
Speaker 1: sounded like he had some answer. So he was sort
Speaker 1: of rewriting the question to fit it was at hawk. Yeah,
Speaker 1: that is what he was called out on that. It
Speaker 1: wasn't like, oh, here is a new understanding of a
Speaker 1: physical law around the Uni verse. This just applied to
Speaker 1: those galaxies in the rotational momentum or rotational acceleration. His
Speaker 1: whole position was that that breaks down at very small accelerations,
Speaker 1: like a planet on the outside or a star on
Speaker 1: the outside of a galaxy, but over a long distance. Yeah.
Speaker 1: And so a lot of people were like, that's ad hoc.
Speaker 1: It doesn't hold any water. Anyone can do that. Get
Speaker 1: out of here. Yeah. Um. And then apparently there was
Speaker 1: a study in two thousand seven that showed that even
Speaker 1: down to accelerations as slow as five hundred trillions of
Speaker 1: a meter per second squared, which is really low acceleration,
Speaker 1: Newton's second law of motion still held fast. So mind
Speaker 1: is pretty much out out the window. From what I understand,
Speaker 1: Newton is giving the finger from the grave to see
Speaker 1: what you get. He very famously liked to say, bite it.
Speaker 1: It's on his tombstone. I think, Uh, what else do
Speaker 1: we have here? Um? Alternative wise, this guy, I love
Speaker 1: this dude's name. I looked it up, Dragon H. Kovic.
Speaker 1: Oh he is he one of the guys at CERN. Yeah.
Speaker 1: I can do better than that, Dragon, Hey Dukevich, hy Dukevich, Sorry,
Speaker 1: draw on, but yeah, he said that there's such things
Speaker 1: as um gravit pollar gravitational polar opposites to particles and
Speaker 1: anti particles have not only opposite electrical charges, but opposite
Speaker 1: gravitational charges. Yeah. So if those are near a galaxy,
Speaker 1: then it would strenk sort of like a magnet almost,
Speaker 1: they'd form pull a dipole. Yeah, so it would strengthen
Speaker 1: the gravitational field. So that's what's accounting for. Uh. In fact,
Speaker 1: I guess he's saying there is no dark matter, right, Yeah,
Speaker 1: he's saying that that's dark matters dipoles gravitational dipoles, which
Speaker 1: is interesting because that means if that's correct, then if
Speaker 1: you got your hands on an antiparticle, it would fall
Speaker 1: upward because they have it would have an opposite gravitational energy. Yeah,
Speaker 1: that's pretty neat. It's pretty neat. I would love to
Speaker 1: have like a pencil made of any particles used to
Speaker 1: be like, watch this right, just knock everyone sucks right off. So, uh,
Speaker 1: should we talk about that? That's what I would do
Speaker 1: if I had a whole bunch of anti particles. That's
Speaker 1: that's where my imagination ends. Should we talk about the
Speaker 1: Big Bang a little bit? Yeah? Because this is the thing,
Speaker 1: Like if you've been sitting here going like, come on,
Speaker 1: why does this matter at all? It actually does matter
Speaker 1: if we want to figure out how the universe can
Speaker 1: possibly end, right, which is your specialty these days. Man,
Speaker 1: I'm so excited about this coming out. Yeah, we're talking again.
Speaker 1: Josh's upcoming tin part series, The End of the World.
Speaker 1: The End of the World. Yeah, it's um slated to
Speaker 1: come out in November seven, and it's this and more
Speaker 1: time Sten literally Timesten. Yeah, what other stuff you talk
Speaker 1: about ai I know that's in there, ai UM, reckless
Speaker 1: experiments with viruses, FAMI paradox, the Great filter, um, the
Speaker 1: whole things about existential risks. Man, it's you're getting smarter.
Speaker 1: I'm just talking about the old movies. It's down. Yeah,
Speaker 1: but you're like getting in there with people, you know,
Speaker 1: like the heart of people. It's just different. It's not better. Well,
Speaker 1: you've got interviews and stuff though, with like like leading experts, right, yeah,
Speaker 1: but I kind of used them as like a Greek
Speaker 1: course to kind of chime in and help like explain
Speaker 1: it or be like, yeah, Josh is actually right here,
Speaker 1: you know that kind of like it's not just me
Speaker 1: saying it's all right. So look for that everyone. But
Speaker 1: with the Big Bang, the idea is that the universe
Speaker 1: is expanding, and the big question is where what's the endgame? There?
Speaker 1: Are we gonna expand forever? And what does that mean
Speaker 1: in relation to dark matter? So again, this is the
Speaker 1: point that we're at. We've actually figured out what the
Speaker 1: density of the universe has to be. There's something called
Speaker 1: a critical density, and it's tend to the negative twenty
Speaker 1: nine grams per cubic centimeter, which this article says is
Speaker 1: equivalent to a few hydrogen atoms in a phone booth.
Speaker 1: That density of matter, and if the unit that is
Speaker 1: the critical density of of matter in the universe, if
Speaker 1: it's more than that, equal to that, are less than that,
Speaker 1: there are three different possible outcomes for the universe depending
Speaker 1: on how dense the universes with matter. Right, and a
Speaker 1: phone booth everyone is a thing, a box that used
Speaker 1: to hold public telephones that you would step into to
Speaker 1: make a call. Yeah, what's a good movie you can
Speaker 1: go watch to see? There's one called booth. Oh yeah,
Speaker 1: I said a good movie the right. Uh, Superman changes
Speaker 1: his clothes in a phone booth. There you go go
Speaker 1: watch the original Christo Reef Christopher reef um Superman. Right.
Speaker 1: Or imagine if you were laying dead in a casket
Speaker 1: and someone set you up, and you were on your
Speaker 1: cell phone, but you were only three hydrogen atoms and
Speaker 1: your cell phone is connected to a machine chord r exactly.
Speaker 1: Oh all right, So where we were talking about the
Speaker 1: critical density of the universe, right, So there are a
Speaker 1: few different uh outcomes here that they've they've come up
Speaker 1: with as far as where we're headed. Yeah, So if
Speaker 1: if the universe has a density of matter, all the
Speaker 1: matter in the universe, if you could, if you could
Speaker 1: just slice the universe up into phone booths and equally
Speaker 1: spread out all of the matter in the universe across
Speaker 1: all those phone booths, if that equals just a few
Speaker 1: hydrogen atoms per phone booth. Again, that's the critical mass density.
Speaker 1: And if that is actually the same as the density
Speaker 1: of matter in the universe, then what we have is
Speaker 1: a universe that keeps expanding forever, because the universe started
Speaker 1: inflating at some point after the Big Bang. And this
Speaker 1: is a huge discovery in and of itself. Right, everybody
Speaker 1: thought the universe is just kind of there and unchanging. No,
Speaker 1: the universe is actually expanding inside. It's inflating, and the
Speaker 1: matter in the universe is actually spreading away from it.
Speaker 1: So everybody's like, like you said, what's the endgame that
Speaker 1: if it's if the universe, if the universal mass is
Speaker 1: the same as the critical mass density, it's gonna just
Speaker 1: keep expanding forever. But eventually it'll it'll get kind of cool,
Speaker 1: and everything's gonna die and stop. I think it's called
Speaker 1: the heat death of the universe. Yeah, and that's called
Speaker 1: critical or flat universe. If the actual mass density is
Speaker 1: greater than the critical mass density, they call that the
Speaker 1: big crunch. That's not good to close the universe. That
Speaker 1: means it'll expand and then eventually slow down, stop expanding,
Speaker 1: and then collapse on itself. Right like you you know
Speaker 1: those a bungee uh um swings. Yeah, my daughter was
Speaker 1: just on one of those. Okay, So they launched up
Speaker 1: in the air, right, yep, Well they she she she
Speaker 1: went that way, and then she came back this way,
Speaker 1: she did. So when you come back this way. When
Speaker 1: when you came back this way is because the universe
Speaker 1: is closed and the gravity because of the mass, was
Speaker 1: greater than the critical mass density, and so gravity overcame
Speaker 1: it and brought it back together in what was called
Speaker 1: the big crunch, which I'm assuming she did not undergo.
Speaker 1: I tried to explain that to her, and all she
Speaker 1: said was again again, I don't blame her. Uh. And
Speaker 1: then finally we have another outcome. If actual mass density
Speaker 1: is less than critical mass density, then we keep expanding,
Speaker 1: but there's no change in the rate of expansion. Doesn't
Speaker 1: we don't start expanding faster and faster, right, and I
Speaker 1: think nothing really cools off. It just keeps going forever,
Speaker 1: which is kind of the all good one. Really. That's
Speaker 1: called the Waterson universe, right, alright, alright, alright, or specifically
Speaker 1: the coasting or open universe. I like that, ak Waterson.
Speaker 1: So the only way to figure this out for Shure
Speaker 1: is to live until the end of the universe, and
Speaker 1: we're talking billions, possibly trillions of years into the future,
Speaker 1: or we could just figure out how much matter there
Speaker 1: really is. The problem is, even if we can account
Speaker 1: for all the regular matter, every bit of things that
Speaker 1: makes up you, me, and everything we can see in
Speaker 1: the universe, we still have to account for dark matter.
Speaker 1: Hence the reason why people are mapping dark matter. So
Speaker 1: we can figure truly how much matters in the universe,
Speaker 1: and then we can predict how it's gonna end. Yeah,
Speaker 1: it's not just uh folly and like, hey, this would
Speaker 1: be neat. I mean part of it is. Yeah, there's
Speaker 1: a part of sandwich and a glass of milk at
Speaker 1: the end of that calculation. That's true. Uh, And I
Speaker 1: want to say you got anything else, but I'm not
Speaker 1: going to say that I got nothing else. All right,
Speaker 1: well that's dark matter. Don't even get us started on
Speaker 1: dark energy. Please, please, God, don't get us started on
Speaker 1: dark energy. Uh. If you want to more about dark matter,
Speaker 1: type that word into the search bar. Of those words
Speaker 1: in the search bar. And since I said that it's
Speaker 1: time for listening to mail, I'm gonna call this uh
Speaker 1: something on game shows, Hey, guys, always um wonder what
Speaker 1: it was like to have a moment where they say
Speaker 1: I have to write into stuff you should know for
Speaker 1: listener mail. Well I just had that moment yesterday. I
Speaker 1: listened to the Select podcast on Game shows that wasn't
Speaker 1: a Select podcast, that was just a live show. Oh yeah, right,
Speaker 1: and they fooled me. I love all your episodes, but
Speaker 1: I found this one particularly fascinating. Last forwarded. This evening,
Speaker 1: my fiance and I were sitting down to watch a movie.
Speaker 1: I'm not much of a movie person, sorry, Chuck. So
Speaker 1: I told Peter Guess her fiance to just pick something
Speaker 1: to watch. He puts on quiz show, Oh Emil, not
Speaker 1: realizing it was based on the real life of it.
Speaker 1: So I started telling Peter about your podcast. And now
Speaker 1: quiz shows like this one on the movie were rigged
Speaker 1: in the fifties and it almost killed game shows. I
Speaker 1: was like a sponge releasing all the information I had
Speaker 1: heard yesterday. The chance that he selects that movie the
Speaker 1: day after I listened to your podcast just blows my mind. Awesome.
Speaker 1: It's a Mandela effect, right, syncretism. Anyway, thank you for
Speaker 1: what you do for keeping me company as a drive
Speaker 1: around d C on the belt Way every day. Oh
Speaker 1: you poor person. I know when one of your episodes
Speaker 1: cueues up, I know my drive will go so much faster.
Speaker 1: Lots of love, Kristen, Thanks a lot, Kristin. I was
Speaker 1: a greed email. We're glad we could help you out.
Speaker 1: Make it look pretty good in front of Peter. Yeah.
Speaker 1: Good luck with the upcoming wedding, yeah, which we assume
Speaker 1: is impending. Okay, um, well, if you want to let
Speaker 1: us know you're getting married, let us know, we'll say
Speaker 1: best wishes. Every once while, somebody will send an invitation in.
Speaker 1: We're not taking them up, but we usually sign it
Speaker 1: and send it back at least. Yeah. I mean, if
Speaker 1: someone was getting married here in the studio on a
Speaker 1: Tuesday at one o'clock, we'd be there, and we'd also
Speaker 1: be like, we need the studio exactly. Uh so maybe
Speaker 1: make it twelve o'clock. Uh. If you want to get
Speaker 1: in touch with us, you can hang out with us
Speaker 1: on social media. Just go to what's our website dot com.
Speaker 1: That's right, um, and you'll find all the links there
Speaker 1: and um. You can also send us an email. Just
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