Latest / Daniel and Kelly’s Extraordinary Universe / Where is the coldest place in the Universe?

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Where is the coldest place in the Universe? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, Daniel, what's your least favorite topic in physics? Oh, man,
0:13
Speaker 1: don't make me say something negative about physics. Well, now
0:16
Speaker 1: I really want to know. Fine, Fine, it's thermodynamics. You
0:20
Speaker 1: don't like thermodynamics. But it's such a hot field, Daniel,
0:25
Speaker 1: or cold, depending on the state. It's just too hard
0:29
Speaker 1: to get my mind around. There's so many particles involved,
0:31
Speaker 1: you know, So you don't know much about thermodynamics, then
0:35
Speaker 1: I wouldn't say I know that much. Really, like you
0:37
Speaker 1: know zero about it? You're getting close. What if we
0:40
Speaker 1: talk about absolute zero? That's a reasonable approximation of how
0:44
Speaker 1: much I like thermodynamics. I am or handmade cartoonists and
1:04
Speaker 1: the creator of PhD comics. Hi, I'm Daniel. I'm a
1:08
Speaker 1: particle physicist, and I'm not a lover of thermodynamics. Now,
1:11
Speaker 1: welcome to our podcast, Daniel and Jorge Explain the Universe,
1:14
Speaker 1: a production of I Heart Radio in which we find
1:17
Speaker 1: all the amazing and crazy things about the universe, the
1:21
Speaker 1: extreme things, the fast things, the hot things, the cold things,
1:24
Speaker 1: and we explain them all to you. That's right. We
1:27
Speaker 1: explore all of the hot topics in physics and science
1:30
Speaker 1: out there in the universe, but also the coldest thing sometimes,
1:34
Speaker 1: that's right. We try to touch on the hot topics
1:36
Speaker 1: and we try to be cool at the same time.
1:39
Speaker 1: We are. We are pretty cool for a physics podcast.
1:43
Speaker 1: We're definitely cool. Yeah, all all three of them were
1:48
Speaker 1: probably the coolest, but yeah. This is part of a
1:51
Speaker 1: series of podcast episodes about the extremes of the universe.
1:56
Speaker 1: Should we cue the heavy metal sounds, Danny Wild Stallions,
2:01
Speaker 1: where we're gonna get Bill and Ted on the podcast,
2:03
Speaker 1: Oh we should build or Ted just before their reunion tour.
2:08
Speaker 1: We like talking about the crazy bits of the universe
2:10
Speaker 1: because where the extremes are sort of where you learn
2:13
Speaker 1: the most about the universe. How hot can things get?
2:16
Speaker 1: What is the densest thing, what is the strongest magnetic field?
2:19
Speaker 1: And that's why we explored all those topics in previous episodes. Yeah,
2:23
Speaker 1: it really makes you kind of push or stretch the
2:26
Speaker 1: boundaries of your mind, you know, to think of the
2:28
Speaker 1: hottest things, the dancest things, the brightest things. Those are
2:32
Speaker 1: all things we've covered in other episodes, and today we'll
2:35
Speaker 1: be talking about another one of those extremes in the universe.
2:39
Speaker 1: So today on the podcast, we'll be talking about what
2:47
Speaker 1: is the coldest place in the universe. Instead of heavy
2:51
Speaker 1: metal guitar, we should just have a cold wind or something. No,
2:56
Speaker 1: we should have the theme music from Frozen, of course,
3:01
Speaker 1: come on, just let it go, Just let it go. No.
3:05
Speaker 1: I love the extremes of the universe because they remind
3:07
Speaker 1: us that where we live is not usual. And this
3:10
Speaker 1: is this big lesson in physics that you can't just
3:12
Speaker 1: look the stuff around you and then try to generalize
3:14
Speaker 1: to the whole universe. You can't assume that everything around
3:17
Speaker 1: you is typical, that things on other planets and other
3:21
Speaker 1: parts of the universe follow the same rules. We've often
3:24
Speaker 1: made that mistake in physics and then learned that the
3:26
Speaker 1: universe works in totally different ways. And we learned that
3:29
Speaker 1: when we look far and wide, we explore the extremes,
3:32
Speaker 1: we look for the hottest, the fastest, the brightest, the
3:35
Speaker 1: weirdest stuff. That's where lessons lie, that's where we find
3:38
Speaker 1: new physics. And so today we'll be talking about what
3:41
Speaker 1: is the coldest place in the universe, And um, I
3:46
Speaker 1: hear it that it's probably not what most people expect.
3:49
Speaker 1: I hear it's not Nancy Pelosi's cold Stare that was
3:54
Speaker 1: pretty chilling though, But yeah, this is a topic in
3:57
Speaker 1: statistical and thermodynamics, and I to admit this is not
4:01
Speaker 1: my number one favorite field of physics. Not because I
4:04
Speaker 1: don't think it's awesome. It is really awesome, and the
4:06
Speaker 1: kind of things that people have developed are really pretty cool,
4:09
Speaker 1: but it's it can be sort of frustrating to think about,
4:13
Speaker 1: and I particularly find it um sort of intimidating as
4:16
Speaker 1: a topic to talk about coldness or or just temperature
4:20
Speaker 1: and thermodynamics in general. Well, just thinking about like systems
4:23
Speaker 1: of particles. I mean, let me reaf you. And as
4:26
Speaker 1: an example, the opening paragraph of the Statistical Mechanics book
4:30
Speaker 1: from grad school. Oh please, no, I know it doesn't
4:35
Speaker 1: sound riveting, but whole lover a moment, all right, all right.
4:39
Speaker 1: Ludwind Boltzmann, who spent much of his life studying statistical mechanics,
4:43
Speaker 1: died in nineteen o six by his own hand. Paul Aaronfest,
4:48
Speaker 1: carrying on his work, died similarly in three Now it
4:52
Speaker 1: is our turn to study statistical mechanics. That's that's the
4:57
Speaker 1: scene right there. You know, the legends of the field
5:00
Speaker 1: killed themselves thinking about this, So now let's study it.
5:04
Speaker 1: Do you think because it was just such an intense
5:06
Speaker 1: topic or that, um, it's a dangerous thing to study.
5:11
Speaker 1: I don't think. I don't think the topic itself is dangerous.
5:14
Speaker 1: Something you're like summoning demons from below that infest your
5:17
Speaker 1: mind or anything. But it is hard. It's tricky stuff.
5:20
Speaker 1: You have to understand. You know, how gases move and
5:23
Speaker 1: how they flow in terms of these tiny, little microscopic particles,
5:27
Speaker 1: and so there's a lot of complicated statistics and difficult mathematics.
5:31
Speaker 1: It's amazing what they have achieved. And one of the
5:33
Speaker 1: greatest accomplishments, of course, is understanding like our experience of temperature.
5:38
Speaker 1: You know, you touch something it feels hot, you touch
5:40
Speaker 1: something feels cold, understand that in terms of what that
5:43
Speaker 1: means for the microscopic particles. That connection kind of makes
5:46
Speaker 1: you uncomfortable. Yeah, well it's it's not makes me uncomfortable.
5:50
Speaker 1: It's just sort of difficult sometimes to think about what
5:53
Speaker 1: it means mathematically. But it's also awesome because it lets
5:56
Speaker 1: you understand how things around you arise from the most
6:00
Speaker 1: you know, those microscopic particles. We'll dig into into that
6:03
Speaker 1: in a moment, but you know, this, this fascinating extension
6:06
Speaker 1: is like how cold can things get? How much can
6:09
Speaker 1: you push that? You know, if coldness really is about
6:11
Speaker 1: the motion of the particles inside something slowing down, then
6:15
Speaker 1: like can you push it as far as you can go?
6:17
Speaker 1: And how far exactly can the universe take you on
6:20
Speaker 1: the temperature scale. Yeah, So part of what we'll be
6:23
Speaker 1: talking about today is this concept of absolute zero, as
6:28
Speaker 1: in that is theoretically possibly the coldest that you could
6:32
Speaker 1: possibly ever get in the universe. And so the question
6:36
Speaker 1: is there such a place out there in the universe?
6:38
Speaker 1: Can there be such a place out there in the universe?
6:40
Speaker 1: That's the question we'll be tackling today. And so I
6:44
Speaker 1: was wondering if people had heard about this phrase. It
6:46
Speaker 1: seems sort of common and awesome. You know, it's got
6:48
Speaker 1: a nice zing too. It's got pizzazz right as most
6:52
Speaker 1: physics terms don't. And just to be clear, this is
6:55
Speaker 1: not an endorsement for a vodka drink. It also not
7:00
Speaker 1: not an endorsement for vodka, though we're not anti vodka
7:03
Speaker 1: on this show. Are you saying are you saying call us?
7:08
Speaker 1: Are you saying to absolute callus? Well, we'll totally take
7:11
Speaker 1: a case of your vodka. We're saying absolute zero about vodka. Right,
7:16
Speaker 1: we're not saying anything positive. We're not saying anything negative
7:18
Speaker 1: about vodka. But maybe the podcast would be funnier if
7:24
Speaker 1: sample there is that drunk history show, which is pretty funny.
7:27
Speaker 1: I don't think there's a drunk physics show yet, So yeah,
7:30
Speaker 1: put that on the list of projects. We should start
7:32
Speaker 1: a new series of episodes physics. Daniel and Jorge slur
7:39
Speaker 1: their way through the universe. But which one would be drunk?
7:42
Speaker 1: Do you or me? The audience should be drunk so
7:45
Speaker 1: they can understand us, or so they can like our jokes.
7:49
Speaker 1: Daniel and Jorge drinking game. Every time Daniel says that's right,
7:53
Speaker 1: or every time Jorge says bananas, somebody takes a shot.
7:58
Speaker 1: I can see this being all the rage in college
8:00
Speaker 1: Fra Trinity houses. Speaking of colleges, I walked around campus
8:03
Speaker 1: that you see Irvine, and I asked people what they
8:05
Speaker 1: knew about absolute zero and if they thought it was
8:08
Speaker 1: just sort of a crazy theoretical idea or something we
8:11
Speaker 1: could possibly achieve. So, as usual, Daniel went around and
8:14
Speaker 1: asked the question what is absolute zero? So before you
8:18
Speaker 1: hear the answers, think about it for a second. If
8:20
Speaker 1: someone approached you out of the blue and ask you
8:23
Speaker 1: what absolute zero is, what would you answer. Here's what
8:26
Speaker 1: people had to say, absolute zero. It's something that I
8:30
Speaker 1: can't recalltop my head. I've heard it before. Temperature zero kelvin.
8:36
Speaker 1: Is it possible for anything to actually get to absolute zero?
8:39
Speaker 1: I don't think so. I believe that's like a measure
8:41
Speaker 1: of temperature. I think if we were measuring in kelvin,
8:45
Speaker 1: that's like the lowest anything could ever go. Can something
8:48
Speaker 1: actually get to absolute zero? Uh? Theoretically yes, but physically
8:52
Speaker 1: we haven't gone there yet. Of some understanding, I actually
8:55
Speaker 1: don't know, but it sounds somewhat familiar. Absolute zero is
8:59
Speaker 1: zero kelvin. It's the coldest possible temperatures, eat, death of
9:03
Speaker 1: the universe, or however you want to say it. So
9:06
Speaker 1: is it possible for something to physically achieved zero? Uh? So.
9:12
Speaker 1: I believe it is extremely difficult to get to absolute
9:17
Speaker 1: zero properly, but people have achieved some number of desmal
9:21
Speaker 1: places very very close to this. But I think that
9:24
Speaker 1: some of the matter based effects can be realized at
9:29
Speaker 1: maybe higher temperatures and capsolute zero, like the helium three
9:33
Speaker 1: and things like that. Superfluidity, Yes, superfluid. It's the coldest
9:37
Speaker 1: possible temperature when everything stops moving and we've never gotten there.
9:41
Speaker 1: So is it physically possible to get something absolute zero? Uh?
9:45
Speaker 1: I don't know. I'm the wrong person as zero on
9:48
Speaker 1: the Kelvin scale just no movement, no energy. Is that
9:53
Speaker 1: physically achieved? Just theoretical? I believe theoretic here, So it's
9:57
Speaker 1: impossible to get to epsoide zero. I don't think so.
10:00
Speaker 1: All right, some pretty good answers. I thought, no mentions
10:02
Speaker 1: of vodka. Yeah, I guess vodka is pretty expensive for
10:05
Speaker 1: college students. Well, you see, Irvine does have the reputation
10:09
Speaker 1: of being sort of the nerdy you see campus, like,
10:12
Speaker 1: that's where you go if you want to really be
10:14
Speaker 1: serious about your studies. I think, Santa Barbara, you might
10:17
Speaker 1: to get different answers. All right, so you're saying, um,
10:20
Speaker 1: that you're not surprised then that people a lot of
10:22
Speaker 1: people knew what absolute zero was, and some people evedn't
10:25
Speaker 1: talked about the heat death of the universe and how
10:28
Speaker 1: it's sort of theoretical as well. Yeah, these were some
10:30
Speaker 1: seriously good answers, and I think there's a lot of
10:33
Speaker 1: interest there so I think, um, let's dig into it
10:36
Speaker 1: and talk to people about what absolute zero is and
10:38
Speaker 1: how cold we can actually get and if we can
10:41
Speaker 1: find it somewhere in the universe. I think the answer
10:44
Speaker 1: is might be pretty surprising. I guess maybe let's just
10:47
Speaker 1: start with what is coldness? Like, what does it mean
10:49
Speaker 1: for something to be cold at all? Yeah, it's sort
10:51
Speaker 1: of fascinating. Um, whether like coldness or heat is a thing? Right, Like,
10:57
Speaker 1: if heat is a thing, then coldness is sort of
10:59
Speaker 1: like the sense of that thing. But if you were
11:01
Speaker 1: sort of like an early person thinking about thermodynamics, it
11:04
Speaker 1: could have been that like coldness was a thing and
11:07
Speaker 1: heat was the opposite of it. But it turns out
11:09
Speaker 1: that like heat is a thing, heat is the motion
11:12
Speaker 1: of particles. We were talking earlier about this connection between
11:16
Speaker 1: your experience of temperature and that what's happening for the
11:19
Speaker 1: microscopic particles, and that's really what it is. Temperature is
11:22
Speaker 1: a measurement of sort of the speed of how fast
11:25
Speaker 1: these particles are moving or shaking. That sounds like a
11:28
Speaker 1: really deep question, like is heat the absence of coldness
11:31
Speaker 1: or is coldness the absence of heat? Yeah? What is
11:34
Speaker 1: the sound of one thermometer measuring. Yeah, it's a it's
11:39
Speaker 1: a fascinating question. But it turns out that heat is
11:41
Speaker 1: the thing, right. Heat is the motion of particles and
11:44
Speaker 1: coldness is the absence of that motion, and so there's
11:47
Speaker 1: all sorts of fascinating consequences of that. And we really
11:50
Speaker 1: got into this when we talked about um we had
11:53
Speaker 1: an episode about temperature about and I got really confused
11:55
Speaker 1: about how you know, you were saying temperature is actually
11:59
Speaker 1: not like it's a thing, but it's sort of an
12:02
Speaker 1: average thing. Like you can't measure the temperature of a
12:05
Speaker 1: single particle. That's really weird to me. Yeah, in our
12:08
Speaker 1: episode about what is the hottest thing in the universe,
12:11
Speaker 1: we got into that because there's a lot of weird
12:12
Speaker 1: stuff that's like really hot things that are three d
12:15
Speaker 1: million degrees, but if you went inside them you would
12:18
Speaker 1: freeze to death because they're really dilute um. So the
12:21
Speaker 1: concept of temperature is very confusing, especially as you get
12:24
Speaker 1: two very high energies. And you're right, temperature is not
12:26
Speaker 1: the property of a single particle to property of a
12:29
Speaker 1: system of particles. That has to do with the essentially
12:31
Speaker 1: the average motion. And I got really hung up on
12:34
Speaker 1: like um. So you can't take the temperature of a
12:36
Speaker 1: single particle. Can you take the temperature of two particles?
12:40
Speaker 1: You can't take the temperature of a single particle. In theory,
12:43
Speaker 1: you can only take the temperature of an infinite number
12:46
Speaker 1: of particles. But in practice a large number of particles
12:50
Speaker 1: approximated infinite number pretty quickly, So to definitely not a billion,
12:55
Speaker 1: probably a million, almost certainly a thousand, maybe circumstances. It's
13:01
Speaker 1: one of these fuzzy things, you know, like when does
13:04
Speaker 1: the practical match the theoretical. It's like saying, like, what's
13:07
Speaker 1: the death of an ocean? You know, you can't apply
13:10
Speaker 1: that to a single water molecule. You have to apply
13:12
Speaker 1: to a huge number of water particles. It's a concept
13:15
Speaker 1: that only exists for a system of particles, bunch of things, Yeah,
13:19
Speaker 1: not for an individual. Yeah. And so for coldness, it's
13:23
Speaker 1: the it's not the emotion of the stuff, it's the
13:25
Speaker 1: lack of motion. So I guess maybe coldness is not
13:28
Speaker 1: a thing. Then you're saying heat. Heat is a thing
13:31
Speaker 1: because you can measure it, but coldness is just like
13:34
Speaker 1: if the thing is not there, there's no motion of
13:37
Speaker 1: the particles. Yeah, coldness is to heat, what like silence
13:42
Speaker 1: is to noise. Right, is silence a thing or it's
13:44
Speaker 1: the lack of noise In the same way, coldness is
13:47
Speaker 1: the lack of heat. You know, heat is the motion
13:50
Speaker 1: of these particles. They can move, they can spin, they
13:52
Speaker 1: can vibrate. All that stores energy, right, and that energy
13:56
Speaker 1: is the heat of the system. And as that energy
13:59
Speaker 1: leaves that the object gets colder and colder, those little
14:02
Speaker 1: particles move less and less. I feel like we're asking
14:05
Speaker 1: some really deep questions, Daniel. Well, this is what I
14:07
Speaker 1: love about physics, you know. It touches on really simple,
14:10
Speaker 1: basic d questions. And this is why we're always bumping
14:12
Speaker 1: into sort of philosophy questions because physics is important. And
14:17
Speaker 1: so if you think about you know, this is like
14:19
Speaker 1: the motion of particles. You can imagine the particles like
14:22
Speaker 1: moving more and more and more and getting hotter and
14:24
Speaker 1: hotter and hotter, and that's sort of continuing off to infinity. Right,
14:27
Speaker 1: there's no limit to how much these particles can shake
14:30
Speaker 1: or wiggle or whatever. But the other direction, as things
14:33
Speaker 1: get colder and colder, things move less and less. It's
14:36
Speaker 1: fascinating if there is sort of a negative limit there
14:39
Speaker 1: that you approach like zero motion like silence, right, Like
14:42
Speaker 1: you can have zero silence, but you can't have negative silence. Yeah,
14:48
Speaker 1: you can't have negative silence or like super silence. You know,
14:53
Speaker 1: you can't have like extra extra silence a silence. You
14:56
Speaker 1: can't have negative noise. I guess, yeah, yeah, And that's
14:59
Speaker 1: what it is for amperature, right, it's um. Once you
15:01
Speaker 1: had zero, you can't get any colder. It's that's what
15:05
Speaker 1: it's called absolute zero. Yeah. Absolute zero is the idea
15:09
Speaker 1: that maybe you have a bunch of particles together and
15:11
Speaker 1: then they just stopped moving, that they formed like a
15:15
Speaker 1: perfect crystal. There's no entry be left at all. There's
15:18
Speaker 1: only one way to arrange the system. There's no motion,
15:21
Speaker 1: there's no rotation, there's no vibration. So that's the idea
15:25
Speaker 1: of it, right, that every particle in your system is
15:28
Speaker 1: not moving at all. Zero right now, kinetic energy, if
15:33
Speaker 1: you could achieve that, then that would be absolute zero.
15:36
Speaker 1: And it's it's really a fascinating topic if you look
15:39
Speaker 1: in the history of this concept, like people start first
15:41
Speaker 1: started thinking like huh, could this be possible? Even before
15:44
Speaker 1: people try to make things super duper cold, to try
15:47
Speaker 1: to achieve it. They started to think about is it
15:49
Speaker 1: theoretically possible? And one thing they noticed was they were like,
15:53
Speaker 1: let's look at how things change as a function temperature.
15:55
Speaker 1: And you know, different substances like have different melting boiling points,
15:59
Speaker 1: and that depends on the substance. Water melts or boils
16:02
Speaker 1: at different temperatures than you know, oil or other substances. Right, Like,
16:06
Speaker 1: let's just play around with sticking things in the freezer
16:09
Speaker 1: and see what happens. Yeah, but all of these things
16:11
Speaker 1: all point towards the same zero point, right, water or
16:15
Speaker 1: hydrogen or oil or whatever, they all have the same
16:19
Speaker 1: same absolute zero. This concept of an absolute zero is universal.
16:23
Speaker 1: Would be the same temperature for every substance at zero.
16:26
Speaker 1: Like it's you're saying, it's just when everything, no matter
16:30
Speaker 1: what substance you are or what you're made out of,
16:32
Speaker 1: you at some point might or could reach zero. Precisely,
16:36
Speaker 1: it doesn't vary depending on what you are, Like when
16:39
Speaker 1: you're freezing or boiling. It's like it's it's there for everybody,
16:42
Speaker 1: including you and me and everyone listening. Because those other
16:46
Speaker 1: transitions like melting and boiling, those have to do with
16:49
Speaker 1: like how the molecules are sticking together or not sticking together, whatever.
16:53
Speaker 1: So they're really dependent on the structure in the shape
16:55
Speaker 1: of those molecules. That's why water and other materials boil
16:58
Speaker 1: at different temperatures. But when it comes to not moving
17:01
Speaker 1: at all, it doesn't really matter what shape you are
17:03
Speaker 1: or what size you are, and you're just doing nothing,
17:05
Speaker 1: and everybody does nothing in the same way. Right, what
17:08
Speaker 1: about absolute vodka? Would that also have an absolute zero? Absolutely? Absolutely?
17:15
Speaker 1: All right? So that's that's coldness, and that's absolute zero.
17:19
Speaker 1: It's this theoretical limit of when everything is no longer moving.
17:23
Speaker 1: And so let's get into have we reached absolute zero
17:28
Speaker 1: and we if we can even get there, or if
17:31
Speaker 1: there are places in the universe that are that have
17:33
Speaker 1: absolute zero temperature. But first let's take a quick break,
17:49
Speaker 1: all right, Daniel, how cold are physicists or how cold
17:55
Speaker 1: have physicists gone? We're a pretty cool group of dudes. Um.
18:00
Speaker 1: But there's this, really there's a really fun sort of history,
18:05
Speaker 1: a race to the bottom or everybody was wondering like
18:09
Speaker 1: how cold can you get something? And people were developing
18:12
Speaker 1: technology try to make stuff colder and colder, and it's
18:15
Speaker 1: not that easy, right, You want to make something really cold,
18:18
Speaker 1: you need something else really cold. And so to make
18:21
Speaker 1: something colder than anything you've ever seen before, take some cleverness, right,
18:25
Speaker 1: because you're trying to take away To make something colder,
18:28
Speaker 1: you have to take away energy, right, And to take
18:31
Speaker 1: away energy you have to kind of like grab it, right.
18:34
Speaker 1: You need something that is colder to take it away
18:37
Speaker 1: from the thing you're trying to cool down. So it's
18:40
Speaker 1: a it's a tough problem, I guess. Yeah, if you
18:41
Speaker 1: want to freeze your ice cream, you put it in
18:43
Speaker 1: the freezer, and the freezer the stuff around the ice
18:46
Speaker 1: cream and the freezer is colder, so the heat leaks
18:49
Speaker 1: out of that ice cream um into this stuff in
18:51
Speaker 1: the freezer warms up the air and the freezer a
18:53
Speaker 1: little bit. It doesn't come back. And I think it's
18:55
Speaker 1: the key. Like if you leave ice cream out in
18:58
Speaker 1: outside of the freezer, there's you know, there's energy going
19:02
Speaker 1: into it and out of it, into it and out
19:03
Speaker 1: of it, but mostly going into it. But in the freezer,
19:07
Speaker 1: it just leaves the ice cream and it doesn't come back, Yeah,
19:10
Speaker 1: because the freezer is actively cooling it down. But you
19:12
Speaker 1: can also do it in a cooler, right, say, just
19:14
Speaker 1: pack ice cream surrounded by really cold stuff and a
19:17
Speaker 1: cooler so it's all sealed off. Then if the stuff
19:20
Speaker 1: around the ice cream is colder, then they'll tend to equilibrate.
19:23
Speaker 1: The heat will flow out of the ice cream and
19:25
Speaker 1: into the colder stuff. So classic way to make something
19:28
Speaker 1: colder is to put it next to something that's even
19:31
Speaker 1: colder than it. Right, But if you're trying to make
19:34
Speaker 1: the coldest thing ever, you can't do that because you
19:37
Speaker 1: would need something even colder. And so the race to
19:39
Speaker 1: reach the coldest temperature started a long time ago. It
19:43
Speaker 1: seems you wrote here that it started in the eighteen hundreds. Yeah,
19:48
Speaker 1: people were trying to make stuff really cold. Back in
19:50
Speaker 1: eight It was Michael Faraday. He's a famous guy in physics,
19:54
Speaker 1: and he achieved a temperature of negative a hundred and
19:57
Speaker 1: thirty degrees celsius. That's a hundred and forty three degrees calvin.
20:02
Speaker 1: That's really cold. It's pretty impressive for the eight hundreds,
20:05
Speaker 1: isn't it. I mean they didn't even have telephones. They
20:10
Speaker 1: couldn't call each other and brag about how I got
20:14
Speaker 1: some ice cream on guys coming over. Nope, you have
20:17
Speaker 1: to send a letter. Yeah, the first thing they tried
20:21
Speaker 1: to do is to take gases from the air, hydrogen
20:24
Speaker 1: or oxygen and stuff like this, and to liquefy it
20:27
Speaker 1: to make it, you know, liquefied or even solid. He
20:30
Speaker 1: was the first one to do that, to liquify any gas.
20:32
Speaker 1: And then thirty years later some French guys whose names
20:35
Speaker 1: I can't pronounce because I can't read French very well,
20:38
Speaker 1: they liquefied air. They got it down to negative a
20:40
Speaker 1: hundred and ninety five degrees celsius. That's just seventy eight
20:44
Speaker 1: degrees kelvin, right, and for those of us who are
20:47
Speaker 1: in fahrenheit, that means um also a negative large number exactly.
20:55
Speaker 1: And you might wonder, like, how are these guys doing this,
20:57
Speaker 1: how are they making this cold? Well, the the basic
21:00
Speaker 1: trick they were doing is they're lowering the pressure, because
21:03
Speaker 1: these gases are complicated things, and if you lower the
21:06
Speaker 1: pressure of a gas, it ends up cooling down. If
21:08
Speaker 1: you keep like the amount of gas constant and use
21:12
Speaker 1: and you somehow stretch it or lower the pressure, then
21:14
Speaker 1: it automatically gets colder. Right, yeah, precisely. And that's the
21:18
Speaker 1: kind of stuff that always melted my brain, you know,
21:20
Speaker 1: like you have the same amount of frozer brain and
21:22
Speaker 1: gave your brain freeze or melted your brain, both at
21:25
Speaker 1: the same time. And that's why. But then we have
21:30
Speaker 1: a series of guys making advancements. In eighty three, somebody
21:34
Speaker 1: liquefied oxygen down to fifty five degrees kelvin and then
21:39
Speaker 1: in door liquefied hydrogen, and of course he's famous for
21:44
Speaker 1: inventing the doer, right, which is this like cold flask.
21:47
Speaker 1: You've probably seen a lot of laboratories that's down to
21:50
Speaker 1: twenty one degrees kelvin. So they're little by little, sort
21:54
Speaker 1: of one up in each other, you know, getting colder
21:56
Speaker 1: and colder because they use different gases or did they
22:00
Speaker 1: just have better techniques. They just sort of expanded on
22:03
Speaker 1: this technique of figuring out ways to suck heat out
22:06
Speaker 1: by expanding the volume and then pulling out the coldest parts,
22:10
Speaker 1: and then expanding that and then pulling out the coldest parts.
22:12
Speaker 1: So it's all about this sort of experimental chemistry cleverness.
22:16
Speaker 1: And this is way before you know, any sort of
22:19
Speaker 1: advanced technologies, right. So these guys were just kind of
22:22
Speaker 1: like you know, experimenting with um like flasks and boilers
22:27
Speaker 1: and things like that, right, pretty basic, you know chemistry setups. Yeah,
22:31
Speaker 1: they had you know, glass tubes and rubber valves and
22:34
Speaker 1: this kind of stuff, and they had no complicated technology
22:37
Speaker 1: at all. Um And then it was in nineteen o
22:39
Speaker 1: eight they finally liquefied helium that brought them down to
22:44
Speaker 1: four degrees kelvin and then even further down to one
22:48
Speaker 1: and a half degrees calvin. And this guy who did it,
22:50
Speaker 1: he won the Nobel Prize for that. It was like
22:52
Speaker 1: such an achievement to get such cold temperatures. That was
22:55
Speaker 1: like the forefront of exploration because he went from like
22:58
Speaker 1: twenty calvin to one kelvin. Yeah, that's a huge jump. Yeah,
23:01
Speaker 1: that's a pretty big change fractutionally, and it gets you
23:04
Speaker 1: pretty close to absolute zero. Did they have a sense
23:06
Speaker 1: that there was an absolute zero? You know? Do you
23:08
Speaker 1: know what I mean? Like, did they know that at
23:11
Speaker 1: some point you would hit rock bottom? Yeah? They had
23:14
Speaker 1: this idea because they were studying sort of the temperature
23:18
Speaker 1: as a function of pressure and volume and all this stuff,
23:21
Speaker 1: and you know, these temperature curves all point in the
23:24
Speaker 1: same direction, and no matter what gas you're talking about, helium, hydrogen, oxygen,
23:28
Speaker 1: all those lines were sort of converging at the same
23:32
Speaker 1: point at absolute zero. So they had the idea that
23:35
Speaker 1: this existed, and they were sort of pushing to see
23:37
Speaker 1: how close they could get. But they were all wondering, like,
23:39
Speaker 1: is it possible to actually achieve something at absolute zero's
23:43
Speaker 1: just sort of a theoretical concept, or can it actually
23:46
Speaker 1: exist in and how is it you could have this
23:48
Speaker 1: like theoretical concept that you could never actually achieve in practice.
23:51
Speaker 1: That's sort of weird, right, if you can or cannot
23:54
Speaker 1: achieve it, right, it's sort of it's a big unknown, Yeah,
23:57
Speaker 1: but it would it would be weird to have this
23:59
Speaker 1: theoretical a concept that's a just a straightforward extrapolation of
24:02
Speaker 1: things we observe, but then have it be sort of unachievable.
24:06
Speaker 1: If that's the case, it tells you something pretty deep
24:08
Speaker 1: about the universe. And so people kept going, right, people,
24:11
Speaker 1: and nowadays, what's like, what's the record lowest temperature we
24:15
Speaker 1: can get to? Yeah, so people work really hard on
24:17
Speaker 1: this now and the current record is much better than
24:21
Speaker 1: like the Nobel Prize winning record at one point five
24:25
Speaker 1: degrees kelvin. Right now we're at a hundred pico Kelvin's
24:30
Speaker 1: Pico Kelvin's that's like one with nine zeros in front
24:34
Speaker 1: of it or behind it. Yeah. Yeah, it's a zero
24:36
Speaker 1: point zero zor zero zero or zero zero zero zero
24:40
Speaker 1: one kelvin. Wow. So we've been able to cool something
24:44
Speaker 1: down that cold. Yeah, well, I mean not me and
24:48
Speaker 1: not you. Some people out there working really hard and
24:51
Speaker 1: it's the collective we a is in the part of
24:54
Speaker 1: humanity that I'm proud to call myself a part of. Yeah.
24:57
Speaker 1: So that's the current record, and you know, the is
25:00
Speaker 1: fascinating theoretically, but it's also it's hard to do. You know,
25:04
Speaker 1: it's it's hard to accomplish this. As we were saying before,
25:06
Speaker 1: Like you get something super duper cold, you need clever tricks.
25:10
Speaker 1: Do they use something kind of special trick there? Yeah,
25:12
Speaker 1: they do this thing which is really fascinating. It sounds
25:15
Speaker 1: um counterintuitive. They use laser cooling like a cold ray. No, No,
25:19
Speaker 1: it's a hot ray, just like normal, right, it's not
25:22
Speaker 1: like a cold laser. That would be awesome. And in
25:25
Speaker 1: the comic book version of US, I definitely want eyeballs
25:28
Speaker 1: that shoot out cold lasers that can freeze things. There's
25:30
Speaker 1: a Batman villain called Mr. Freeze. Yeah, precisely. But okay,
25:34
Speaker 1: but this is not This isn't like a regular you know,
25:37
Speaker 1: zapping laser, and somehow that cools things. And the way
25:41
Speaker 1: it makes things cold is not by touching them and
25:45
Speaker 1: taking away their heat. It's by selecting the hot stuff
25:48
Speaker 1: and pushing it out of the way. So imagine you
25:51
Speaker 1: have a big blob of gas. Not every atom in
25:55
Speaker 1: that blob of gas is moving at the same speed.
25:58
Speaker 1: That's a distribution. Some are moving after some removing colder.
26:01
Speaker 1: If you could just select the cold ones, then the
26:04
Speaker 1: average temperature would go down. Oh, I see, but you
26:07
Speaker 1: can actually aim this laser or how does that work?
26:09
Speaker 1: Or like the lasers some somehow only picks out the
26:13
Speaker 1: fast moving atoms. Yeah, it's pretty complicated, but essentially the
26:16
Speaker 1: idea is to get the fast moving atoms in the
26:19
Speaker 1: path of the laser and so they didn't knocks them
26:21
Speaker 1: out of the way. And you use a laser because
26:23
Speaker 1: it's you can't just like go in there and flick
26:25
Speaker 1: out individual atoms with a mechanical object. The laser is
26:27
Speaker 1: the best way to interact with an individual atom. You
26:29
Speaker 1: can just like blow on it. They tried that six
26:34
Speaker 1: years later that guy still hadn't graduated. No Nobel prize
26:37
Speaker 1: for no PhD even No. So that's the idea instead
26:41
Speaker 1: of trying to cool down the whole sample, right, which
26:44
Speaker 1: is what you do when you put your ice cream
26:46
Speaker 1: in the freezer, instead they just pick out the cold bits.
26:49
Speaker 1: It's like if I gave you a bowl of ice
26:51
Speaker 1: cream and you're like, hey, it's kind of melted, and
26:53
Speaker 1: I just sort of scooped out the hot bits and
26:55
Speaker 1: left you with the colder bits of ice cream. You know,
26:58
Speaker 1: that's not really cooling down your ice cream, but the
27:00
Speaker 1: temperature of the ice cream you're left with is colder.
27:03
Speaker 1: And so that's the current record right now, is that
27:05
Speaker 1: the cold is that humans have been able to cool
27:08
Speaker 1: something down is a hundred pico kelvin. Yeah, and that's
27:12
Speaker 1: colder than outer space. You know, the average temperature out
27:15
Speaker 1: there in space is like two point seven three degrees kelvin,
27:18
Speaker 1: which sounds kind of hot in comparison. Yeah a minute
27:21
Speaker 1: ago that sounded chili, right, but compared to a hundred
27:24
Speaker 1: peeko kelvin's it's like bust out your swimsuit. Um. And
27:27
Speaker 1: that's the temperature average temperature out there in space there's
27:30
Speaker 1: some spots out there in space where lots of gases
27:33
Speaker 1: have been like blowing out of a star, and that
27:35
Speaker 1: expansion cools it down to maybe one degree kelvin. But
27:39
Speaker 1: the coldest natural thing, we think is one degree kelvin
27:44
Speaker 1: and the current record is a hundred peco kelvins. But
27:46
Speaker 1: humans are not finished. You think we can go further
27:50
Speaker 1: colder than Yeah, there's a there's an instrument right now
27:54
Speaker 1: on the International Space Station. That's where they're doing this experiment.
27:57
Speaker 1: And it's like you've got to be surrounded by m
28:00
Speaker 1: D space just to even have a chance to do this.
28:02
Speaker 1: And it's called the Cold Atom Lab, and their goals
28:05
Speaker 1: to get down to one pico calvin down from a
28:08
Speaker 1: hundred which is the current record. Maybe helped me paint
28:10
Speaker 1: a picture here what's going on at that temperature like
28:13
Speaker 1: or the atoms? Not very much? All right, that's that's about.
28:19
Speaker 1: It's like the conversation at your average physics party, you know,
28:21
Speaker 1: just like nobody's talking, everybody just sitting there, everyone's just
28:25
Speaker 1: thinking about absolute zero. Now, there is some wiggling. If
28:29
Speaker 1: you were to zoom down microscopically and look at these things,
28:31
Speaker 1: there would be some energy. There's some motion of these particles,
28:35
Speaker 1: like like each atom is maybe not moving across the room,
28:39
Speaker 1: but they are sort of wiggling and vibrating. And these
28:42
Speaker 1: are all crystals, right, so you imagine they have bonds
28:44
Speaker 1: with each other. They're not totally separate atoms. Imagine like
28:47
Speaker 1: a lattice and you have these atoms with these bonds
28:50
Speaker 1: holding them in place, and then occasionally you get like
28:53
Speaker 1: a little wiggle, a little bit of sound goes through
28:57
Speaker 1: the material. Hey, that's a cool connection actually between temperature
28:59
Speaker 1: and sound. Right. Sound probably does have a temperature because
29:02
Speaker 1: it's the wiggling and motion of these of the material.
29:06
Speaker 1: I never thought about that. Man, I'm gonna need another
29:08
Speaker 1: shot just to consider that question, Daniel. When you get
29:11
Speaker 1: down to those temperatures, things form into a crystal, because
29:14
Speaker 1: what else are they going to do. Can you take
29:16
Speaker 1: a gas down to that cold of a temperature or
29:20
Speaker 1: does it have to form into a solid by that?
29:23
Speaker 1: I think it has to form into a solid idea.
29:25
Speaker 1: And I'm not a chemist, So maybe somebody out there
29:27
Speaker 1: who knows more chemistry than I do knows whether or
29:29
Speaker 1: not you could keep something a gas and still make
29:32
Speaker 1: it really cold. I think it would have to be
29:34
Speaker 1: super duper dilute, right, But essentially, you know, these molecules
29:38
Speaker 1: have no vibrational energy, no rotational energy anymore, and no
29:42
Speaker 1: translational energy. They're not moving, so they're just all sitting
29:46
Speaker 1: in place. Whether or not it's a crystal or a gas,
29:48
Speaker 1: I guess just depends on how tightly you're packing them.
29:51
Speaker 1: But effectively this becomes how you define a gas or
29:56
Speaker 1: a solid, right, yeah, and probably an absolute zero. You know,
30:00
Speaker 1: it's one of those places where the phases are not
30:02
Speaker 1: well to find, you know, how the chemistry they have
30:04
Speaker 1: these like triple points where something is like, what is
30:06
Speaker 1: it exactly if you're right at the triple point? Absolute
30:09
Speaker 1: zero is probably like that. But you know, the fascinating
30:11
Speaker 1: question is like how close absolute zero could you experimentally get,
30:16
Speaker 1: Like is it possible to make a material with exactly
30:19
Speaker 1: zero motion? All right, well, let's get into that, whether
30:22
Speaker 1: it's even possible to reach absolute zero. And I think
30:25
Speaker 1: for me, the more the interesting question is if there
30:28
Speaker 1: are places in the universe that are absolute zero. So
30:31
Speaker 1: let's get into that. But first let's take another break.
30:47
Speaker 1: All right, Daniel, can we get there? Can we get
30:49
Speaker 1: to absolute zero? Without drinking absolute vodka. I think it is.
30:54
Speaker 1: They're totally not sponsored by liquor company um. But yeah,
31:01
Speaker 1: can we get too absolutely Is it even possible or
31:04
Speaker 1: like many of the people you interviewed on the street,
31:06
Speaker 1: isn't only theoretical that you can get to absolute zero?
31:10
Speaker 1: I think unfortunately, there is no amount of you can
31:13
Speaker 1: drink to get us down to absolute zero. I think
31:16
Speaker 1: theoretically it's impossible. It's impossible. Yeah, it's just not possible.
31:20
Speaker 1: I think in the sort of the classical theory that
31:23
Speaker 1: the folks who were first coming up with thermodynamics thought about,
31:27
Speaker 1: you know, they're thinking about particles is a lot of
31:29
Speaker 1: tiny little balls, and so you can talk about their
31:31
Speaker 1: motion and their location in that context. It is possible.
31:34
Speaker 1: But we know better now. We know that when you
31:37
Speaker 1: get down to tiny particles, there are different rules that apply.
31:40
Speaker 1: These particles don't have classical paths, they don't move in
31:44
Speaker 1: a way that makes sense to us. Their quantum mechanical
31:47
Speaker 1: Maybe even the idea of energy at that point gets fuzzy, right,
31:51
Speaker 1: like the idea of kinetic energy, whether there's something's moving
31:53
Speaker 1: or not. At the quantum level, it's sort of like undefined, right, yeah, well,
31:57
Speaker 1: we'll dig into that in a whole separate episode of energy.
32:00
Speaker 1: I gotta say, if several folks, like maybe dozens of
32:03
Speaker 1: folks have written in asking us to do a podcast
32:05
Speaker 1: episode about energy and what does it mean? And how
32:07
Speaker 1: do you transfer one form to the other and quantum
32:09
Speaker 1: mechanically doesn't make any sense. So we'll dig into that
32:11
Speaker 1: a whole separate episode when we get the energy to
32:14
Speaker 1: do it will after we're done drinking that bottle of vodka.
32:19
Speaker 1: But the problem is that as you get really really cold,
32:22
Speaker 1: you come down to this zero point energy. Right. Quantum
32:25
Speaker 1: mechanics says that there are fluctuations everywhere, even in empty space.
32:30
Speaker 1: There's a small amount of energy, and that energy is
32:32
Speaker 1: constantly fluctuating. You have these quantum fields that are going
32:35
Speaker 1: up and down, so you have particles being created, and
32:37
Speaker 1: so it's impossible to get down to zero energy because
32:41
Speaker 1: there's always some energy even in empty space. But is
32:44
Speaker 1: it fluctuations or is it just uncertainty? Do you know?
32:48
Speaker 1: Do you know what I mean? Like it's or like
32:49
Speaker 1: randomness or is there even a difference? Well, there's both.
32:53
Speaker 1: There's you know, we think that the mean energy of
32:55
Speaker 1: empty space is not zero, that there is energy stored
32:58
Speaker 1: in empty space, and so you just can get rid
33:00
Speaker 1: of this is just a property of space itself to
33:02
Speaker 1: have energy. Not even nothingness is absolute zero, yeah, because
33:06
Speaker 1: there is no such thing as nothingness. You can't have
33:09
Speaker 1: space without nothing. That's the property of space is that
33:11
Speaker 1: it has quantum fields. And these quantum fields that we
33:14
Speaker 1: talked about the Higgs Boson episode don't settle at zero.
33:17
Speaker 1: They settle it's some energy above zero. Space is something,
33:21
Speaker 1: space is something. So there so there's no nothingness. Actually yeah, well,
33:25
Speaker 1: and that's a whole other concept. You know, how do
33:27
Speaker 1: you get something from nothing? And what is nothingness? Or
33:30
Speaker 1: maybe maybe it's fair to say space without anything in
33:33
Speaker 1: it still has energy. Space can't have nothing because it
33:36
Speaker 1: always have quantum fields which have energy. Yeah, there's no nothing, Yeah,
33:40
Speaker 1: there's no nothing. That's the zero point energy concept. That's
33:43
Speaker 1: like you can't get down to zero energy. But even
33:47
Speaker 1: if somehow the universe, you know, even if we like
33:50
Speaker 1: destroy the Higgs field and we got down to a
33:52
Speaker 1: state or vacuum energy of zero, and we talked about
33:54
Speaker 1: that in a separate episode, um, even still there would
33:56
Speaker 1: be quantum mechanical problems because imagine what you do there.
34:00
Speaker 1: You're taking a particle and you're setting its location, right,
34:03
Speaker 1: has no motion, so you have to know its location,
34:05
Speaker 1: and that means you also know it's momentum. But the
34:08
Speaker 1: Heisenberg uncertainty principle says you have a minimum uncertainty in
34:12
Speaker 1: the location and the motion. But when now we're talking
34:15
Speaker 1: about a state where we know exactly the location and
34:17
Speaker 1: the motion, and so that seems like it would violate
34:20
Speaker 1: the uncertainty principle. Well, maybe that just means that there's
34:23
Speaker 1: no like, the absolute coldness of the universe is not
34:26
Speaker 1: zero point zero zero zero zero zero, But could there
34:29
Speaker 1: still be like a minimum temperature of the universe, like
34:32
Speaker 1: a point oh you know one pico pico, pico Keilen
34:37
Speaker 1: or something like that. Oh, that's fascinating. You're saying the
34:40
Speaker 1: minimum might not be zero, but there could be a
34:42
Speaker 1: zero or could you or pretty much zero? I want
34:46
Speaker 1: to hear that announcement scientists announce the achievement of pretty
34:50
Speaker 1: much zero. We did it, We got pretty much nothing. No,
34:56
Speaker 1: that's a really interesting question. Can you ask them topically
34:59
Speaker 1: a pro absolutely zero getting closer and closer forever, or
35:03
Speaker 1: is there a minimum non zero temperature. I think because
35:07
Speaker 1: of the zero point energy of space, there must be
35:09
Speaker 1: a minimum temperature. But if you somehow collapsed the Higgs
35:13
Speaker 1: field and got rid of that minimum energy, then I
35:16
Speaker 1: think you could ask some topically approach zero forever. You're saying,
35:19
Speaker 1: unless the universe destroys itself, there is a limit. And
35:25
Speaker 1: I'm not encouraging anybody to destroy the universe just to
35:27
Speaker 1: win that Nobel prize, just to ask for Horace question,
35:30
Speaker 1: We're going to destroy the universe. That is physicists being
35:34
Speaker 1: drunk with power. Okay, So then, uh so there might
35:38
Speaker 1: be sort of a minimum and you're saying, it's really
35:40
Speaker 1: difficult to get there because space itself doesn't get to zero.
35:43
Speaker 1: So that does that mean that nowhere in the universe
35:46
Speaker 1: do we get that cold or like there's nowhere in
35:48
Speaker 1: the universe that's actually zero. That's right. We think that
35:52
Speaker 1: there is nowhere in the universe it's actually zero, and
35:55
Speaker 1: absent physics labs here on Earth and on the space station,
35:58
Speaker 1: we think the coldest thing in the universe is a
36:00
Speaker 1: out just one kelvin out there in you know, the
36:03
Speaker 1: heart of a frozen planet in the middle of nowhere.
36:07
Speaker 1: It's still about one kelvin. Yeah, most of the stuff
36:10
Speaker 1: out there is about two point seven degrees kelvin. If
36:12
Speaker 1: you really work hard, you might be able to find
36:15
Speaker 1: something at one degree kelvin. But here on Earth we
36:17
Speaker 1: have stuff that's like a hundred Pego Calvin's going down
36:21
Speaker 1: to one Pico Calvin. We hope. Wow. So the coldest
36:25
Speaker 1: place in the entire universe might be here on Earth
36:30
Speaker 1: in somebody's lab, depending of course, on whether there are aliens.
36:34
Speaker 1: So basically we're in a race with alien physicists to
36:37
Speaker 1: get the coldest place on Earth to see who has
36:40
Speaker 1: the who's the coolest species in the universe. You knew
36:44
Speaker 1: I was going to have to bring it back to aliens. Eventually.
36:46
Speaker 1: Every topic has to touch on aliens, right, Yeah, there
36:50
Speaker 1: could be aliens out there who have a lab because
36:55
Speaker 1: they would have to do this on purpose, right, they
36:57
Speaker 1: have a lab that maybe goes down to even colder
36:59
Speaker 1: than us at a hundred people Calevin. Yeah, there could
37:02
Speaker 1: be alien civilizations out there that have been doing physics
37:04
Speaker 1: for a billion years, and you know, to them, like
37:07
Speaker 1: a hundred Pekokelevins is laughable, man, That's like a kindergarten
37:11
Speaker 1: science fair project. For them. Really, they could be way
37:14
Speaker 1: way down further in the cold spectrum. Wow, But we
37:19
Speaker 1: won't know until those aliens come and visit. All right,
37:21
Speaker 1: But as far as we know, barring super advance cool aliens,
37:27
Speaker 1: the coldest place in the universe is here, probably in
37:30
Speaker 1: in the United States, or in the lab in Europe
37:32
Speaker 1: or something. Right, Yeah, and very soon the coldest place
37:36
Speaker 1: in the universe, we think, will be on the International
37:38
Speaker 1: Space Station at the Cold Atom Lab. All right, Well,
37:41
Speaker 1: I think we answered the question pretty well. Where is
37:43
Speaker 1: the coldest place in the universe and whether we could
37:46
Speaker 1: maybe get even colder might not be possible unless we
37:51
Speaker 1: destroy the universe, it seems. But absolute zero is a
37:55
Speaker 1: fascinating topic theoretically, and it's a fascinating goal. We keep
37:58
Speaker 1: pushing more and more, and as we do so, we
38:00
Speaker 1: learn more and more about cooling technology and how to
38:03
Speaker 1: achieve that, and and how things operate into very extremes
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Speaker 1: of the universe, which is where we hope to reveal
38:09
Speaker 1: some new secrets about how the universe works. So the
38:12
Speaker 1: next time you have a scoop of ice cream, think
38:15
Speaker 1: think about how how cold it is and how cold
38:18
Speaker 1: you could get it if you went to your local
38:20
Speaker 1: physics lab and recruited some physicist to give you a
38:23
Speaker 1: better ice cream. Thanks for tuning in for this tasty topic.
38:26
Speaker 1: See you next time. Before you still have a question
38:36
Speaker 1: after listening to all these explanations, please drop us a line.
38:39
Speaker 1: We'd love to hear from you. You can find us
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Speaker 1: on Facebook, Twitter, and Instagram at Daniel and Jorge That's
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Speaker 1: one Word, or email us at Feedback at Daniel and
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Speaker 1: Jorge dot com. Thanks for listening and remember that Daniel
38:52
Speaker 1: and Jorge Explain the Universe is a production of I
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