Latest / Daniel and Kelly’s Extraordinary Universe / What Is the Hottest Thing In The Universe?

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What Is the Hottest Thing In The Universe? · Daniel and Kelly’s Extraordinary Universe

0:07
Speaker 1: Hey, Daniel, do you know the concept of absolute zero?
0:10
Speaker 1: I don't mean the vodka. I mean, like, you know,
0:13
Speaker 1: the concept that there is the coldest possible temperature in
0:17
Speaker 1: the universe. Yeah, And I think that's super awesome. I
0:19
Speaker 1: love when there's something in physics that has an extreme
0:22
Speaker 1: to it, like beyond this point is impossible to go
0:26
Speaker 1: extreme physics. I feel like we should have a heavy
0:29
Speaker 1: metal guitar sound there. Yeah. This podcast brought to you
0:32
Speaker 1: by Mountain dew Rush, the physics dude. But you know,
0:36
Speaker 1: I was asking because I was thinking about what is
0:38
Speaker 1: the opposite of absolute zero temperature? Like is there a
0:42
Speaker 1: maximum temperature in the universe the hottest thing ever or possible? Well,
0:46
Speaker 1: if there's the hottest thing ever, it's probably somewhere here
0:49
Speaker 1: in southern California. But it's a fascinating concept, Like is
0:52
Speaker 1: there a point where after you pump in more energy,
0:54
Speaker 1: it just doesn't get any hotter. It's it's an incredible idea.
0:58
Speaker 1: It's too hot to handle, or two for the universe
1:01
Speaker 1: to be handled, that's right, Yeah, or maybe, uh, you know,
1:04
Speaker 1: after you pumping too much energy, like it just blows
1:07
Speaker 1: up or it crosses a singularity or restarts the universe
1:10
Speaker 1: and makes a glitch in the matrix or something. Well,
1:12
Speaker 1: at some point when you hit some sort of um,
1:15
Speaker 1: you know lights, be kind of maximum limit to the
1:19
Speaker 1: in universe. Yeah, I think the physics police would pull
1:21
Speaker 1: you over and be like, what are you doing? Explained
1:24
Speaker 1: to us how this makes any sense? Um, your your
1:28
Speaker 1: way too, You got it. You gotta cool it down
1:30
Speaker 1: a little bit, leave a little room for the rest
1:32
Speaker 1: of us to be attractive. That's right. Yeah, too much
1:36
Speaker 1: sizzle exactly. Hi, I'm for Hey. I'm a cartoonists and
1:55
Speaker 1: the creator of PhD comics. I'm Daniel. I'm a particle physicist,
1:59
Speaker 1: a part time podcast host, and I've never created an
2:01
Speaker 1: online comic. But I did once write a book about
2:05
Speaker 1: all the things we don't know in the universe together
2:07
Speaker 1: with Jorge, and it's filled with his hilarious comics. It's
2:10
Speaker 1: called We Have No Idea. So you only podcast part time, Daniel,
2:14
Speaker 1: that's right, only ninety hours a week. That's a part
2:17
Speaker 1: time schedule. I have this podcast, I'm going to have
2:19
Speaker 1: eighty nine other podcasts I also do. I thought you
2:22
Speaker 1: were gonna say that's how much editing this podcast needs
2:25
Speaker 1: to get it down to about how much research is
2:28
Speaker 1: required to boil down all these incredible insights into just
2:32
Speaker 1: one hour of time. Well, welcome to our podcast Daniel
2:36
Speaker 1: and Jorge Explain the Universe, a production of I Heart Radio.
2:40
Speaker 1: That's right, and into our podcast. We try to take
2:42
Speaker 1: some topic of general interest, a question people ask every
2:45
Speaker 1: that's something that everybody wants to know about the universe,
2:48
Speaker 1: and break it down in a way that actually makes
2:50
Speaker 1: sense to you and along the way maybe get you
2:52
Speaker 1: to laugh. Yeah, so to be on the podcast, we're
2:55
Speaker 1: doing part two in our unofficial informal series of Universal Extremes.
3:02
Speaker 1: That's right. We thought it'd be fun to take you
3:04
Speaker 1: out of your situation, to pull you out of your ordinary,
3:07
Speaker 1: everyday life, or maybe you have a very exciting life
3:09
Speaker 1: and think about the biggest, fastest, nastiest, hottest, wettest, craziest
3:13
Speaker 1: things in the universe. Sorry, there's probably some skateboarders out there,
3:17
Speaker 1: or some X Game athletes. They are like, you know,
3:18
Speaker 1: my life is pretty extreme already. Man. They have no
3:22
Speaker 1: idea there's somebody out there in the universe surfing on
3:25
Speaker 1: black holes and riding the shock waves of supernova is
3:28
Speaker 1: doing crazy tricks that nobody could have ever imagine. Yeah,
3:31
Speaker 1: so a few weeks ago we did what is the
3:33
Speaker 1: biggest thing in the universe? Then today we are tackling
3:36
Speaker 1: the subject of what is the hottest thing in the universe?
3:46
Speaker 1: Answer you, You are the hottest thing in the universe. Ye,
3:49
Speaker 1: that's right. No, no, no, no, no, not me the
3:51
Speaker 1: person listening to this. Right, that's right, you, our listener,
3:55
Speaker 1: you are the hottest thing. You look great today. Uh yeah,
4:00
Speaker 1: I don't need any flattery, but you know, it would
4:02
Speaker 1: be nice to um pride the audience a little bit,
4:05
Speaker 1: that's right. Not that we're spying on you, not that
4:07
Speaker 1: we're stalking you on social media, but have you been
4:09
Speaker 1: losing weight? You look great? Yeah, totally super hot. But
4:14
Speaker 1: you know, the universe is filled with all sorts of
4:15
Speaker 1: crazy stuff. Here on Earth we have some temperature variations,
4:19
Speaker 1: but you know, even inside our Earth, the temperatures get
4:22
Speaker 1: crazy hot, crazy high numbers that are sort of hard
4:25
Speaker 1: to understand. And so we thought it'd be fun to
4:27
Speaker 1: take a tour of the universe and to think about
4:29
Speaker 1: all the hot places, like where in the universe does
4:33
Speaker 1: it get hot? Where in the universe is the craziest,
4:36
Speaker 1: hottest nastiest furnace that you can imagine. That's right. And
4:39
Speaker 1: it's pretty cool to think. I think about these extreme
4:42
Speaker 1: examples because it really kind of pushes your mind, right,
4:45
Speaker 1: it sort of expands your understanding and your awareness of
4:48
Speaker 1: how crazy thinks and get yeah, and I think you'll
4:51
Speaker 1: be pretty surprised by the answer. I don't think that
4:53
Speaker 1: what physicists think is a hot place in the universe
4:56
Speaker 1: is the kind of thing that anybody would imagine. I
4:58
Speaker 1: was kind of surprised when I doing some reading about this.
5:01
Speaker 1: Oh wow, really, so the hottest thing in the years
5:04
Speaker 1: is maybe the most unexpected it's unexpectedly hot. Yeah, that's right.
5:09
Speaker 1: And when I was thinking about this topic, I was
5:11
Speaker 1: thinking about how often in physics we have a term
5:14
Speaker 1: that we use to describe something, which is also a
5:17
Speaker 1: term in English. You know, like temperature is definitely something
5:19
Speaker 1: we're aware of, right, you know what hot and cold means.
5:22
Speaker 1: You touch things they burn you or they or they
5:25
Speaker 1: freeze you or something. But sometimes in physics we create
5:27
Speaker 1: technical definitions for things like temperature because we want to
5:31
Speaker 1: understand it right. We want to describe it, like where
5:32
Speaker 1: does temperature come from, how does it work? What makes
5:35
Speaker 1: something hot? What makes something cold? But then this thing
5:38
Speaker 1: happens where the technical definition we use in the scientific
5:41
Speaker 1: community deviates a little bit from like the familiar term
5:45
Speaker 1: that people use in their everyday life, and sometimes they
5:47
Speaker 1: can even come into conflict. Is this one of these
5:50
Speaker 1: terms where physicists, Um, so who what? Who came first? Really?
5:54
Speaker 1: The popular conception probably came first, right, Yeah, The concept
5:57
Speaker 1: of temperature is age old, right. People have been talking
6:00
Speaker 1: about people have been dropping hot coals in their toes
6:02
Speaker 1: and screaming curse words and thousands of languages for thousands
6:05
Speaker 1: of years, that's for sure. Um. And then people were
6:08
Speaker 1: studying heat and thinking about like, you know, what is
6:10
Speaker 1: heat and how does it transfer between things? And I
6:13
Speaker 1: had no idea like is it a flow? Is it
6:14
Speaker 1: a liquid? Is in this invisible this thing or that thing?
6:17
Speaker 1: So the study of temperature is just a few hundred
6:19
Speaker 1: years old, but the experience of it, right, the knowledge
6:22
Speaker 1: of hot things and cold things, that's age old. Right. Yeah, Well,
6:25
Speaker 1: let's get into the definition of temperature in in the episode,
6:28
Speaker 1: but fort we were wondering what people thought out there,
6:31
Speaker 1: all of you listening to this. What you guys thought
6:34
Speaker 1: was is the hottest thing in the universe. Yeah, I
6:37
Speaker 1: thought this would be interesting to see what people think
6:38
Speaker 1: about it, and and I give them some a little bit
6:40
Speaker 1: of extra time on this question. I prodded them to
6:42
Speaker 1: think about it a little more deeply if they didn't
6:44
Speaker 1: seem like they gave me an insightful answer right off.
6:47
Speaker 1: So I walked around the campus of UC Irvine, and
6:49
Speaker 1: I asked people, what's the hottest thing in the universe?
6:52
Speaker 1: And you know, here I was obviously digging for compliments,
6:54
Speaker 1: but nobody said me right, Nobody said you, Nobody, nobody.
6:58
Speaker 1: Nobody gave me a compliment on how I look that day.
7:00
Speaker 1: M Maybe it's just what you were wearing. If you
7:05
Speaker 1: had worn something else. It's sandals and shorts every day
7:08
Speaker 1: around here. So you So you walked around and asked
7:10
Speaker 1: people what is the hottest thing in the universe? And
7:13
Speaker 1: generally what what did people say? Right? Well, listen to
7:16
Speaker 1: their responses and you can tell that's the hottest thing
7:18
Speaker 1: in the universe our sun, like the center of it
7:22
Speaker 1: or the surface or say all of it. Okay, Um,
7:27
Speaker 1: probably like one of those big the big stars that
7:32
Speaker 1: you see on the Twitter videos where it's like they
7:34
Speaker 1: get bigger and they get bigger, and I don't know
7:35
Speaker 1: what they're called, scary names, super super giant stars. Yeah, alright,
7:40
Speaker 1: cool in the middle of some really dense star somewhere. Okay,
7:46
Speaker 1: so you think the center of a star is hotter
7:47
Speaker 1: than like it's surface, Yeah, okay, cool. I'd assume it's
7:51
Speaker 1: not the Sun since you're asking me this, but I'll
7:53
Speaker 1: say the sun since I can't think of anything else
7:55
Speaker 1: in the whole universe. Um, I don't know, probably like
7:59
Speaker 1: a planet. Okay, No, I don't know. Um, we'll call
8:04
Speaker 1: it the I don't know, the center of a son. Center.
8:08
Speaker 1: The sounds cool, called it. I don't think that's right,
8:11
Speaker 1: because don't think that's right, because because some of the
8:13
Speaker 1: plasmas they're saying are actually hotter than the sun that
8:16
Speaker 1: we have here, so that can't be right. Uh. Okay,
8:21
Speaker 1: the center the center of the university. Where is the
8:24
Speaker 1: son of the universe? Okay, the Sun, our son? Cool,
8:28
Speaker 1: like at the center of it, or on the surface
8:30
Speaker 1: or somewhere in the middle, somewhere in the middle from okay, cool?
8:34
Speaker 1: All right, So pretty much people said the sun. A
8:38
Speaker 1: lot of people thought it was the sun. Yeah, yeah,
8:40
Speaker 1: people thought it was the sun, and like that's pretty good,
8:42
Speaker 1: Like the sun definitely a big hot thing, so not
8:45
Speaker 1: a terrible answer, right, But I wanted people to think
8:47
Speaker 1: a little more broadly, and sometimes I needled people. I
8:50
Speaker 1: was like, you know, how about the whole universe? But
8:52
Speaker 1: still people like, okay, maybe a different sun, like another star,
8:56
Speaker 1: hotter sun. You know, I don't think we should be
9:00
Speaker 1: insulting our son. I think our son looks great. I
9:03
Speaker 1: don't want to do anything to disturb it. You know,
9:05
Speaker 1: it's I've been operating billions of years beautiful, you know,
9:08
Speaker 1: and it is sort of losing weight every day, isn't it. Yeah? Yeah,
9:11
Speaker 1: exactly despite its brilliance, and people, I guess generally feel
9:16
Speaker 1: like that must be so hot that any nothing could
9:19
Speaker 1: be hotter, right. I see, So you were prodding them
9:21
Speaker 1: to think bigger like the most people said the sun,
9:24
Speaker 1: but then you would ask him like no, I mean
9:25
Speaker 1: like the entire universe. Like I think for a minute,
9:29
Speaker 1: like is the sound really the hottest thing? Isn't there
9:31
Speaker 1: something else? Crazy? I like to think that if it
9:33
Speaker 1: was me and somebody came and asked me about it,
9:35
Speaker 1: and I've done no thinking or no research or whatever,
9:38
Speaker 1: that I would say something like, I don't know, but
9:40
Speaker 1: it must be something hotter than the sun, because I
9:43
Speaker 1: have this feeling like there's always something crazy out there.
9:45
Speaker 1: There's always something out there that blows our minds or
9:48
Speaker 1: surprises us, or it's different or bigger or denser or nastier,
9:52
Speaker 1: you know, or faster than we could ever imagine. You mean,
9:54
Speaker 1: if so many appression on the street, do you imagine
9:56
Speaker 1: that you will just say the most correct and clever,
10:00
Speaker 1: cleverest thing possible. No, No, I don't imagine I would
10:02
Speaker 1: have the answer. I think I would say, I don't know,
10:05
Speaker 1: but it must be hotter than the sun, right, because
10:07
Speaker 1: I can't imagine that the thing that's in our neighborhood
10:10
Speaker 1: happens to be the hottest thing in the whole universe,
10:13
Speaker 1: which is just so crazy. Big. Oh, I see you
10:16
Speaker 1: think that. I see you think that maybe they weren't
10:21
Speaker 1: thinking that there could be something harder than the sun. Yeah,
10:24
Speaker 1: that seems to be what people have. That seems to
10:26
Speaker 1: be the impression people have that the sun is basically
10:29
Speaker 1: peak hotness. Well, maybe they didn't, just they weren't. They
10:31
Speaker 1: weren't just thinking that our sun is the hottest. But
10:33
Speaker 1: I think maybe they were thinking like the inside of
10:36
Speaker 1: the sun that it can't possibly get any hotter than that. Yeah,
10:39
Speaker 1: and you know they're not too far off. The sun
10:41
Speaker 1: is pretty dang hot. But it's like orders of magnitude
10:45
Speaker 1: colder than what we're gonna talk about. Well great, So
10:48
Speaker 1: maybe first before we talk about like temperature and numbers
10:51
Speaker 1: and how hot things are, let's talk about what those
10:53
Speaker 1: numbers mean, so that when you hear like a really
10:55
Speaker 1: big number, you can understand, like, what does that really
10:58
Speaker 1: mean about what's going on in the side that thing,
11:00
Speaker 1: Like what really is temperature? Like, let me ask you, Jorge,
11:03
Speaker 1: how would you define temperature? How would I define um?
11:07
Speaker 1: You know, I mean, I know the scientific answer, which
11:10
Speaker 1: is related to like kinetic energy, but you know, I
11:13
Speaker 1: think on an everyday basis, it's just sort of like
11:15
Speaker 1: it's a feeling, you know. To me, I think it's
11:17
Speaker 1: a feeling whether I feel hot or whether I feel
11:20
Speaker 1: that something is hot, you know what I mean. Like,
11:22
Speaker 1: it's to me, it's not an abstract number. It's more
11:25
Speaker 1: like a feeling, and it could maybe be relative like
11:28
Speaker 1: something if I feel hot and the person next to
11:30
Speaker 1: me doesn't feel hot, then that's the difference of opinion. Yeah,
11:34
Speaker 1: and our experience of temperature, You're right, it's definitely relative. Right,
11:36
Speaker 1: what you feel is actually is the air or water
11:39
Speaker 1: around me hotter or cold earth than I am right.
11:42
Speaker 1: We don't have an absolute sense of temperature. You can
11:44
Speaker 1: do that experiment where you put like, what, one finger
11:47
Speaker 1: in a hot cup of water and another finger in
11:49
Speaker 1: a cold cup of water, and then put them both
11:51
Speaker 1: in a lukewarm cup of water, and then your two
11:54
Speaker 1: fingers will send you two different messages when we'll say
11:56
Speaker 1: this lukewarm water is actually hot, and the other one
11:59
Speaker 1: will say, no, it's actually cold. Because what you're measuring
12:01
Speaker 1: is the relative temperature to your finger, right, right, and
12:04
Speaker 1: also the sense that you've adapted to it as well, right,
12:08
Speaker 1: Like you get used to certain temperatures and so and
12:10
Speaker 1: then they don't feel hot or they don't feel cold,
12:12
Speaker 1: that's right. Yeah, Like you jump in the pool, it
12:14
Speaker 1: feels cold for a moment, and then you're you know,
12:16
Speaker 1: your skin temperature change is a little bit, and you
12:18
Speaker 1: get used to it and then it doesn't feel cold anymore.
12:20
Speaker 1: So our experience of cold is mostly about relative temperatures, right,
12:24
Speaker 1: It's it's actually about is heat being transferred to us
12:27
Speaker 1: or is heat leaving our body? Right, And so it's
12:30
Speaker 1: a very kind of feeling based kind of definition. But
12:34
Speaker 1: I know that there's an official physics definition of it, right,
12:37
Speaker 1: There is an official physics definition, but you know, it's
12:39
Speaker 1: not really super well defined. It's it's a bit surprised,
12:43
Speaker 1: but it's not something that exactly nail down. Like you
12:47
Speaker 1: can define temperature for an infinite number of particles that
12:51
Speaker 1: have been sitting in a box for an infinite amount
12:53
Speaker 1: of time, and that's about it. Like everything else is
12:57
Speaker 1: like sort of rough and hand wavy. What do you mean, Well, temperature,
13:00
Speaker 1: way they define it is a measure basically of how
13:03
Speaker 1: much energy is being stored in a system of particles,
13:06
Speaker 1: but that those particles have to be an equilibrium. I mean,
13:09
Speaker 1: you can't like have hot spots and cold spots and
13:12
Speaker 1: needs to have all washed down, all the all the
13:14
Speaker 1: edges and unevenness needs to have smoothed out. Because temperature,
13:18
Speaker 1: in the physics point of view, is the description of
13:21
Speaker 1: a distribution of the energy of particles in equilibrium after
13:25
Speaker 1: everything has sort of calmed down. Um, you said a
13:27
Speaker 1: lot of words there, Daniel said, I think what you're
13:31
Speaker 1: trying to say, is it's it's like an average temperature.
13:34
Speaker 1: The thing about temperature is that there's sort of two
13:37
Speaker 1: different ideas at play here, right. One is the quality
13:39
Speaker 1: of temperature. This is the feeling that you were talking about,
13:42
Speaker 1: the experience we have, right, which is really more about
13:45
Speaker 1: like the transfer of heat between hotter things and colder things.
13:48
Speaker 1: That's what we're experiencing, and that's also what thermometers are measuring. Right.
13:52
Speaker 1: A thermometer gets into equilibrium with the thing it's measuring,
13:55
Speaker 1: the heat transfers from it to the thermometer. But then
13:58
Speaker 1: scientists spend a lot of time trying to understand, like
14:01
Speaker 1: how does that arise? What is the microscopic property of something?
14:06
Speaker 1: How does that property change when things get hot or cold? Right?
14:09
Speaker 1: What is going on inside this stuff when it gets
14:12
Speaker 1: hot and cold? How can we define temperature theoretically and
14:16
Speaker 1: understand it rather than just measuring it? Right, That's what
14:18
Speaker 1: physicists want to do. So they came up with a
14:21
Speaker 1: way to define temperature, actually two different ways. At least.
14:24
Speaker 1: One way is related to like the mean energy of
14:26
Speaker 1: the particles, right, and the other is the relationship between
14:29
Speaker 1: the energy of the system and its entropy. Okay, so
14:32
Speaker 1: it gets kind of technical. But the thing to understand
14:35
Speaker 1: about these definitions are you can't actually measure these theoretical
14:38
Speaker 1: quantities directly and exactly right. You can't go in and
14:41
Speaker 1: measure the energy of particles individually. What you can do
14:45
Speaker 1: is measure the heat flow using thermometers. Right, So these
14:48
Speaker 1: theoretical things are connected to what we measure, but they're
14:51
Speaker 1: not exactly the same thing. And the other thing is
14:54
Speaker 1: that these theoretical concepts, they only really make sense for
14:57
Speaker 1: a system of particles in equilibrium because their statistical concepts.
15:02
Speaker 1: So what that means is that the theoretical definition can
15:05
Speaker 1: deviate from our intuitive experience of temperature. Some things, if
15:09
Speaker 1: they're like if they're not an equilibrium or they don't
15:11
Speaker 1: have enough particles to be called like a system, they
15:14
Speaker 1: don't even really have a well defined temperature or one
15:17
Speaker 1: that can be actually measured or practically measured. What do
15:20
Speaker 1: you mean what doesn't have a temperature? Well, for example,
15:22
Speaker 1: one particle, like a single particle, doesn't have a temperature,
15:26
Speaker 1: Like what's the temperature a single particle? It's not defined
15:29
Speaker 1: from for a for physics temperature, right, there's like, well,
15:33
Speaker 1: you know person temperature, the kind of temperature you and
15:35
Speaker 1: I talk about when we get into a pool. But
15:37
Speaker 1: when we're talking about temperature from like a physics point
15:40
Speaker 1: of view, a single particle doesn't have a temperature because
15:42
Speaker 1: it's the property of a system. Right, But what if
15:44
Speaker 1: your system only has one particle, then it doesn't have
15:47
Speaker 1: a well defined temperature. What do you mean, what if
15:49
Speaker 1: there's this cuban space that only has one particle. You
15:53
Speaker 1: can't say that that cube as a temperature. You can't.
15:55
Speaker 1: That's right, And it's even weirder systum situations that you
15:58
Speaker 1: can't say have a temperature, like say you have wait,
16:00
Speaker 1: what about two particles? How many particles you need to
16:02
Speaker 1: have a temperature? That's not even well defined technically, you
16:05
Speaker 1: need infinite number because you need to be in total
16:08
Speaker 1: thermal equilibrium. That's the thing. Temperature is only well defined
16:11
Speaker 1: for things in thermal equilibrium, which means there's no hot
16:14
Speaker 1: spots and no cold spots. Everything is sort of even down, right,
16:17
Speaker 1: You had an infinite amount of time for all the
16:19
Speaker 1: hot and the cold to wash out, right, So you're
16:22
Speaker 1: saying nothing. Technically, nothing can have a temperature because nothing
16:26
Speaker 1: can be have infinite particles. Yeah, but you know, like
16:30
Speaker 1: a drop of water has tended the twenty three or
16:33
Speaker 1: so particles and it tended to one particles in it.
16:35
Speaker 1: That's a good approximation of infinity. And so yes, you
16:39
Speaker 1: can talk about the temperature of a drop of water.
16:42
Speaker 1: You know, it's an excellent approximation of infinity. One particle, No,
16:45
Speaker 1: two particles, no, five particles, no. How many particles do
16:49
Speaker 1: you need before you can call a temperature that's not
16:51
Speaker 1: even well defined? And then also how much do you
16:54
Speaker 1: have to wait until you can claim that there's it's
16:57
Speaker 1: an equilibrium? Right? That's right. So for people to who
17:00
Speaker 1: don't know what I mean when I say equilibrium, take
17:02
Speaker 1: for example, so you have like a bag of gas,
17:04
Speaker 1: and that gas is that like ten degrees. You have
17:07
Speaker 1: another bag of gas that's like, I don't know, ninety
17:09
Speaker 1: degrees or something. Now those are both in equilibrium. They
17:12
Speaker 1: have temperatures, right, so you put them together into another bag. Right,
17:16
Speaker 1: what's the temperature of that new gas? What you might say,
17:20
Speaker 1: I don't know the average of ten and ninety, Well
17:22
Speaker 1: that's fifty, right, But until those wash shout and all
17:26
Speaker 1: of smushes around, physicists say there is no temperature, like
17:30
Speaker 1: you just can't define it. So that's frustrating, right, because
17:33
Speaker 1: it can. It's like gets in your mind, like that
17:36
Speaker 1: doesn't make any sense. And you're right because you're using
17:38
Speaker 1: like the temperature that you think about in English, right,
17:41
Speaker 1: temperature is a word in English. We have defined this
17:44
Speaker 1: other thing, you know, call it physics temperature, which is
17:47
Speaker 1: very closely related to English temperature. Right, but it's not
17:50
Speaker 1: exactly the same thing. And later on I'll give you
17:53
Speaker 1: an example of something which physics says is super duper hot.
17:56
Speaker 1: It has a huge high temperature value. But if we
17:59
Speaker 1: drop doing it, you would freeze. Hm. There is no
18:07
Speaker 1: true temperature technically, but you know, we can't work with ideals,
18:13
Speaker 1: so we kind of approximate it. That's right, exactly, And
18:16
Speaker 1: anything more than you know, a billion particles, it's not
18:19
Speaker 1: a big deal. It works fine, um, But for if
18:22
Speaker 1: you want to talk about one particle, two particles, three particles,
18:24
Speaker 1: there isn't really a definition of temperature. And I feel
18:27
Speaker 1: like the whole this whole episode could have just been like, hey,
18:29
Speaker 1: what is temperature? And we could I could spend an
18:33
Speaker 1: hour talking about this. I know that's a pretty hot
18:35
Speaker 1: rabbit hole. Yeah, it's a hot topic. But um so,
18:40
Speaker 1: so you're saying it's the mean energy, but I've heard
18:42
Speaker 1: it's the mean kinetic energy. What's the difference. Well, kinetic
18:45
Speaker 1: energy applies to speed, right, how fast are these particles
18:48
Speaker 1: dipping around? And it makes a lot of sense intuitively
18:50
Speaker 1: when you think about an object, like in a solid,
18:54
Speaker 1: things are colder and things and they're not moving around
18:56
Speaker 1: as much, maybe they're even trapped in a lattice, and
18:58
Speaker 1: a liquid things are moving around more, which allows a
19:00
Speaker 1: liquid to flow. In the gas, things are zipping around
19:03
Speaker 1: really fast. Right, it's related to the speed. But particles
19:06
Speaker 1: can store energy in other ways. It just don't. They
19:08
Speaker 1: don't just have to move quickly. They can also like
19:11
Speaker 1: spin or you know, they can vibrate if they have
19:13
Speaker 1: complex chemical bonds, etcetera. So they can store energy in
19:16
Speaker 1: other ways. So really, temperature is related to all the
19:18
Speaker 1: ways a particle can store energy. The speed is a
19:21
Speaker 1: great one, okay, Yeah, And it makes perfect and tutive sense.
19:24
Speaker 1: And so as you're thinking about these things being hot
19:26
Speaker 1: or cold, you know, think about them wiggling more right,
19:29
Speaker 1: like the way temperature arises. The reason things are hot
19:32
Speaker 1: is that the particles in them are wiggling more. And
19:34
Speaker 1: that's also like why you get burned. You know, you
19:36
Speaker 1: get burned because you touch something hot. Those particles are
19:39
Speaker 1: wiggling a lot, so they're bouncing off your finger and
19:41
Speaker 1: depositing a lot of energy, which is why your temperature
19:44
Speaker 1: heats up. Right, it wiggles the particles in your finger.
19:46
Speaker 1: That's how heat is transferred, right, Okay, cool, All right,
19:50
Speaker 1: So that's a that's a definition of temperature. It only
19:53
Speaker 1: took us twenty minutes to get here. I know these
19:56
Speaker 1: things sometimes are surprisingly subtle. Yeah, but so let's get
20:00
Speaker 1: into then, now the universe, and let's talk about like
20:03
Speaker 1: the coldest thing and the hottest thing. But first let's
20:06
Speaker 1: take a quick break. All right, we're talking about the
20:21
Speaker 1: hottest thing in the universe, and so let's take a
20:23
Speaker 1: tour of hotness in the universe. I feel like we're
20:26
Speaker 1: back in the nineties. Remember that website Are You Hot
20:28
Speaker 1: or Not? I think that website. Even mentioning that website
20:33
Speaker 1: is sexual harassment for all of our listeners. Oh boy, Yeah,
20:38
Speaker 1: the nineties were pretty frog with people made some bad
20:43
Speaker 1: choices in the nineties. Yeah exactly, But no, I do
20:46
Speaker 1: remember that website, not that I ever participated, And I
20:48
Speaker 1: didn't objective by anybody in the internet. But I did
20:51
Speaker 1: hear about that website from people. Oh I see, you
20:53
Speaker 1: only heard about it, got it absolutely? All right, Well,
20:57
Speaker 1: let's let's start with that in in on Earth. What
21:00
Speaker 1: some of the hottest things on Earth? Right? Well, first
21:02
Speaker 1: of all, let's clarify what we're talking about. Let's do
21:04
Speaker 1: everything in celsius. Right, So for those listeners in the US,
21:07
Speaker 1: you have to get calibrated. Remember zero twenty minutes talking
21:11
Speaker 1: about celsius versus fahrenheits. We're not going to debate it.
21:14
Speaker 1: We're just going for celsius um for the for the
21:18
Speaker 1: world listeners, um. Zero degrees celsius is the temperature at
21:22
Speaker 1: which water freezes, right, and a hundred degrees, of course
21:25
Speaker 1: is where water boils. And you know, somewhere in the
21:27
Speaker 1: middle is you and me, like our body is about
21:29
Speaker 1: thirty seven degrees celsius, right, And you can have things
21:33
Speaker 1: colder than zero celsius, right, that's right. Absolutely, you can
21:36
Speaker 1: get down to like negative two hundred and seventy three degrees.
21:40
Speaker 1: That's absolute zero, right, And that's where they're the particles
21:44
Speaker 1: of molecules, the things in your thing have no kinetic energy.
21:48
Speaker 1: The things in your thing? Is that a Dr Seu's
21:50
Speaker 1: book about physics? The things in your things, the universal
21:55
Speaker 1: things in your universe. Oh, the things that will wiggle
21:58
Speaker 1: in your things. Um, exactly. Absolute zero is when things
22:02
Speaker 1: are doing no more wiggling, right, They're just to rest.
22:05
Speaker 1: There's no kinnetic energy. Yeah, no, Connecticut, you have masks.
22:08
Speaker 1: You can have energy stored in the particles and atoms,
22:11
Speaker 1: but it's just not moving. That's right, exactly, it's an
22:13
Speaker 1: absolute zero. So that's a negative three degrees c. And
22:17
Speaker 1: then zero is ice seven degree C is the human body.
22:21
Speaker 1: And then the hottest person ever is point five degree c.
22:26
Speaker 1: That's like the hottest anybody ever got? Um with a fever? Wait,
22:30
Speaker 1: that's recorded in the history books. Yeah, exactly what happens
22:34
Speaker 1: when you get hotter than forty six point five? Well,
22:36
Speaker 1: I think your brain cooks and you turn into somebody's meal,
22:40
Speaker 1: you know, Like, I don't think your brain can really
22:42
Speaker 1: survive much more than that. But this is not a
22:44
Speaker 1: biology podcast or a cannibalism podcast, right, um soum. So
22:48
Speaker 1: that's the hottest fever and one has ever gotten and survived.
22:53
Speaker 1: I think is the and survived exactly, yes, um, And
22:57
Speaker 1: then the hottest place on Earth. You know, I think
23:00
Speaker 1: there's a a tight race here because Death Valley. I
23:02
Speaker 1: gotta give my props to Southern Califorment and Death Valley
23:05
Speaker 1: is one of the hottest places on Earth, but it's
23:07
Speaker 1: just edged out by this desert in Iran called the
23:10
Speaker 1: Lute Desert, and it reached seventy one degree celsius, which
23:14
Speaker 1: is really smoking hot. That's the temperature you would feel
23:18
Speaker 1: if you were standing in this desert, exactly. And that
23:21
Speaker 1: is the hottest temperature ever recorded on the surface of
23:23
Speaker 1: the Earth. Is that the hottest air temperature? Do you
23:26
Speaker 1: know what I mean? Because there's definitely hotter things on Earth,
23:29
Speaker 1: Like my frying pan is hotter than that. But you're saying, like,
23:33
Speaker 1: if I just put a thermometer and hold it up
23:35
Speaker 1: in the air, not touching anything or you know, not
23:39
Speaker 1: touching any stoves, that's the hottest place you would feel
23:42
Speaker 1: on Earth. Yeah. No, I think I'm composing an email
23:45
Speaker 1: right now to the Guinstpoker World Records to consider your
23:47
Speaker 1: frying pan to be the hottest place on Earth. Yeah. No,
23:51
Speaker 1: you're right. We do create things on Earth that are hotter,
23:54
Speaker 1: but the hottest naturally occurring air temperature. Man in the
23:58
Speaker 1: caveats just to like, how did defy in the hottest
24:00
Speaker 1: place on Earth. So it's air temperature, hottest air temperature
24:04
Speaker 1: on Earth, barring any sort of like standing next to wildfire.
24:07
Speaker 1: That's right exactly. UM is seventy one degreased C. And
24:12
Speaker 1: you might think, well, that's pretty hot, right, but you
24:14
Speaker 1: know it gets hotter, like even on the Moon. The
24:18
Speaker 1: on the Moon, the the average the average daytime temperature
24:21
Speaker 1: on the Moon is a hundred and one degreas C.
24:24
Speaker 1: I'm just nodding along because that I'm used to fahrenheit.
24:26
Speaker 1: So I'm gonna take your word that that's pretty hot.
24:29
Speaker 1: That's the boiling point of water, dude, Like you put
24:32
Speaker 1: water on the Moon, like it just boils. It's crazy, right, Well,
24:37
Speaker 1: it just it would boil. Um, it would boil anyway
24:40
Speaker 1: because there's no atmosphere. Yeah, that's not surprising. Um on
24:44
Speaker 1: Earth at our regular air pressure, a hundred is when
24:48
Speaker 1: water would boil, yes, exactly. So you know two degrees
24:52
Speaker 1: fahrenheit that's a pretty hot temperature for the surface of
24:55
Speaker 1: the Moon. Um. And then here's this is one of
24:57
Speaker 1: my favorite ones. The hottest temperature ever revived by a
25:01
Speaker 1: living thing. That's a hundred and fifty one degrees celsius, right,
25:06
Speaker 1: that's why. Yeah, that's like much hotter than the boiling
25:09
Speaker 1: point of water. That means that whatever this thing is like,
25:12
Speaker 1: it's uh, it really got fried. And that's of course
25:15
Speaker 1: our friend the Tartar grade. These crazy little water bears
25:18
Speaker 1: that can survive like outer space and being frozen. They're
25:21
Speaker 1: like the hardiest thing on Earth right through tiny little
25:24
Speaker 1: microscopic bugs. Right, yeah, exactly, And you should if you've
25:28
Speaker 1: never heard of a Tartar grade, you should google them.
25:30
Speaker 1: They're incredible. Yeah, scary looking though, I think they look friendly.
25:34
Speaker 1: I'd like to have dinner with the targe. Really, have
25:36
Speaker 1: you been a life size Tartar grade, you would have
25:39
Speaker 1: run the other way immediately. They look like a big snuggle.
25:43
Speaker 1: I mean they're look at the big pillow. I would
25:46
Speaker 1: jump onto a Tartar grade and treat like a bean bag,
25:48
Speaker 1: all right, So that that can to that's the heart
25:50
Speaker 1: that they can survive a hundred and fifty degrees celsis. Yeah,
25:53
Speaker 1: that's the hottest temperature ever survived by a living thing.
25:55
Speaker 1: That's a pretty impressive record. Right, So you could put
25:57
Speaker 1: this in boiling water and put it in boiling water
26:01
Speaker 1: under pressure and it would still survive. That's right exactly. Um.
26:06
Speaker 1: But then leaving the surface of the Earth, the hottest
26:08
Speaker 1: spot of the hottest naturally occurring spot in the Solar
26:11
Speaker 1: System is the surface of Venus, which is four hundred
26:14
Speaker 1: and sixty degrees celsius. And that's because Venus is such
26:17
Speaker 1: a thick cloud layer. It's basically basically climate change gone crazy.
26:21
Speaker 1: All the carbodox in the atmosphere means it's a huge
26:23
Speaker 1: blanket and just soaks up the sun. That's why Venus
26:26
Speaker 1: is hotter than mercury, because it just holds onto the
26:30
Speaker 1: onto the Sun's energy and cooks and cooks and cooks
26:34
Speaker 1: cool And that's in our space. So um, well it's
26:37
Speaker 1: on the surface of Venus, right, That's like the air
26:39
Speaker 1: temperature if you were standing on Venus, that's right, if
26:42
Speaker 1: you weren't cooking eggs, but you were just holding up
26:44
Speaker 1: the thermometer in the surface of Venus, that's what you
26:46
Speaker 1: ad measure, right, Okay, God, But then if you you know,
26:49
Speaker 1: went to the Sun, like a lot of people said, Okay,
26:51
Speaker 1: the sun is the hottest thing. Right. Well, it's true,
26:53
Speaker 1: the Sun is really hot. If you jump to the
26:55
Speaker 1: surface of the Sun, then it gets to like five thousand,
26:58
Speaker 1: five hundred degrees celsius. Wow, that's a that's a lot.
27:02
Speaker 1: Yeah it is. It's really hot. But you know, there
27:04
Speaker 1: are places here in the Earth that are even hotter
27:07
Speaker 1: than the surface of the Sun. Like we talked once
27:10
Speaker 1: in the podcast episode about how the center of the
27:12
Speaker 1: Earth is this crazy liquid iron. Right, Well, the center
27:15
Speaker 1: of the Earth is six thousand degrees um celsius. So
27:19
Speaker 1: that's hotter than the surface of the Sun. So the
27:22
Speaker 1: molecules at the center of the Earth are moving faster
27:25
Speaker 1: than the molecules in the on the surface of the Sun. Yeah,
27:29
Speaker 1: that's right exactly. But the Sun is a huge variation.
27:33
Speaker 1: Like the surface of the Sun is pretty hot, but
27:35
Speaker 1: the corona, like the atmosphere around the Sun is even hotter,
27:40
Speaker 1: hotter than the surface. Yeah, it's weird hot. On the surface,
27:43
Speaker 1: it's five thousand, five hundred degrees celsius, but the atmosphere
27:46
Speaker 1: of the Sun, the corona, is a million degrees celsius.
27:49
Speaker 1: Just because things are moving faster, you know, they're just
27:52
Speaker 1: more chaotic, you know, I don't even think it's that
27:54
Speaker 1: well understood. Like the dynamics of the Sun, how that
27:57
Speaker 1: all works is something that we're still really studying. In fact,
27:59
Speaker 1: there's ending a probe right now to go like orbit
28:02
Speaker 1: the Sun and try to make a bunch of measurements
28:05
Speaker 1: because the Sun is a pretty big mystery. It has
28:06
Speaker 1: this crazy magnetic field we don't understand, and uh, you know,
28:09
Speaker 1: these crazy flares and it's a pretty big deal. So
28:12
Speaker 1: people are trying to understand the Sun. We should do
28:14
Speaker 1: a whole podcast episode about mysteries of the Sun. Wow.
28:17
Speaker 1: So if you grew up in the Earth core and
28:19
Speaker 1: then went to visit the surface of the Sun, you'd
28:21
Speaker 1: be like, oh man, this is like minus five hundred
28:23
Speaker 1: degrees celsius. That's right, you have to pack a jacket.
28:27
Speaker 1: But first you have to get through the Sun's atmosphere
28:29
Speaker 1: in a million degrees celsius. So that'd be pretty tough.
28:31
Speaker 1: Oh I see, really it goes from a million degrees
28:35
Speaker 1: to five thousand degrees. Yeah, it's crazy, right, Like, how
28:37
Speaker 1: can those two things co exist anywhere near each other?
28:40
Speaker 1: And it doesn't really make sense. But I think a
28:41
Speaker 1: lot of that is because the Sun is expelling all
28:44
Speaker 1: this energy, right, and so the the gas the correct
28:47
Speaker 1: in the corona gets heated up. But also I think
28:50
Speaker 1: there's there's something going on here about the definition of temperature. Right.
28:53
Speaker 1: The Sun's corona is not as dense as the surface
28:56
Speaker 1: of the Sun, and some of these things that are
28:58
Speaker 1: really hot are not actually very dense. Yeah, that's kind
29:02
Speaker 1: of what I was alluding to earlier. Right, Like you
29:05
Speaker 1: can if you take the temperature of something that doesn't
29:08
Speaker 1: have a lot of particles or molecules in it, it
29:11
Speaker 1: can still have a temperature, it just wouldn't have a
29:13
Speaker 1: lot of things in it. Yeah, So we can have
29:14
Speaker 1: a high temperature without having a lot of heat, right, Like,
29:17
Speaker 1: there's not a lot of heat to deposit on you.
29:19
Speaker 1: If you put yourself in a box with a very
29:21
Speaker 1: dilute gas that's really really hot, but there's not that
29:24
Speaker 1: much gas in there, right, then it's not going to
29:27
Speaker 1: cook you because it's not that much energy being deposited
29:30
Speaker 1: on your body. For the energy deposit in your body,
29:32
Speaker 1: the particles have to hit you and transfer their energy.
29:34
Speaker 1: But if there's not that many particles, there's not that
29:37
Speaker 1: much to do the cooking. Oh, I see both. Wait
29:39
Speaker 1: when you say, temperature is the average kinetic energy. What
29:43
Speaker 1: do you take the average of like particles? Do you
29:46
Speaker 1: You know, you take the total energy and you divide
29:48
Speaker 1: by the number of particles. What does it mean to
29:50
Speaker 1: take the average? Yeah, it's act the property of the distribution. Actually,
29:54
Speaker 1: so yeah, what we're looking for is the mean of
29:56
Speaker 1: that distribution. Yeah, but you know that's a dangerous we
29:59
Speaker 1: could we could go down that rabbit hole the definition
30:01
Speaker 1: of temperature for another twenty minutes. Be careful. Well, I'm
30:05
Speaker 1: still confused. I know it's tricky. It's tricky. Um, but
30:13
Speaker 1: let's keep going. Um. Then you come back to on Earth, right,
30:16
Speaker 1: and it turns out that we can generate things on
30:18
Speaker 1: Earth that are even hotter than the corona of the
30:21
Speaker 1: Sun for example. Um, when we still used to test
30:24
Speaker 1: nuclear bombs, like on the surface of the Earth. At
30:27
Speaker 1: the core of a nuclear explosion, you get up to
30:29
Speaker 1: like ten to fifty million degrees celsius. Right, These are
30:33
Speaker 1: crazy high numbers that are hard to even think about. Okay,
30:36
Speaker 1: so that means that the molecules at the center of
30:38
Speaker 1: the nuclear exupportion are moving super duper, duper, duper fast. Yeah, exactly,
30:42
Speaker 1: super duper duper fast. And that number fifty million degrees celsius.
30:46
Speaker 1: You know, that's comparable to like really hot astronomical stuff.
30:50
Speaker 1: You know, like for example, when a supernova happens, right,
30:53
Speaker 1: a star goes goes, no, it explodes. Well, that's a
30:56
Speaker 1: similar temperature. Like it's fifty million degrees celsius um in
31:00
Speaker 1: the gas that's expelled by the supernova. Right, that's when
31:04
Speaker 1: I start collapses. Right, That's right, the star collapses and
31:07
Speaker 1: then explodes um. And you know what's left is like
31:09
Speaker 1: a little neutron star or a black hole in the center,
31:12
Speaker 1: and the rest is all this gas that's that's spelled out.
31:15
Speaker 1: That's a spewed out and that's a fifty million degrees celsius. Okay, cool.
31:20
Speaker 1: This surprised me a little bit. It turns out that
31:21
Speaker 1: like supernovas are not even the hottest thing out there
31:24
Speaker 1: in space, even though they're hotter, you know than our sun,
31:26
Speaker 1: and they're hotter than nuclear nuclear bombs going off. The
31:29
Speaker 1: hottest thing that's out there in space is stuff like
31:33
Speaker 1: the intercluster medium that's just like all this gas that's
31:37
Speaker 1: between galaxies. You know how galaxies have a huge amount
31:40
Speaker 1: of gas in the mixed stars, etcetera. But between the
31:43
Speaker 1: galaxies is not totally empty. We did a whole podcast
31:46
Speaker 1: episode about like how empty is space? And then there's
31:48
Speaker 1: these tendrils of gas that connect the galaxies together, and
31:52
Speaker 1: they're pretty thin. That's like not a whole lot of
31:54
Speaker 1: stuff out there. You need like a thousand cubic meters
31:59
Speaker 1: of space just to have one particle. But they are
32:03
Speaker 1: really really hot, Like those particles are really moving and
32:06
Speaker 1: the temperature never number you get is a hundred million
32:10
Speaker 1: degrees celsius. Are they all moving in one direction, you know,
32:15
Speaker 1: like wind? Or are they just sitting in place vibrating
32:18
Speaker 1: really fast? I think there are currents because the reason
32:22
Speaker 1: that this stuff is hot is that they're getting heated, right,
32:24
Speaker 1: They're getting heated by like the black holes at the
32:27
Speaker 1: centers of these galaxies that are pushing on them and
32:30
Speaker 1: the crazy like you know, rubbing of of huge clouds
32:33
Speaker 1: of gas that's spewing stuff out. So I think they're
32:36
Speaker 1: getting the sources the galaxies that probably they're all spewing
32:39
Speaker 1: away from the galaxies, but they're probably our currents. As
32:42
Speaker 1: these galaxies spin and things hit each other, it's probably
32:45
Speaker 1: really complicated. So it's actually kind of in the empty
32:49
Speaker 1: spaces between galaxies that we see some of the hottest
32:51
Speaker 1: stuff in the universe. Yeah, and that's the weird thing.
32:54
Speaker 1: It's it seems empty, and if you went out there
32:56
Speaker 1: and like look for particles, you wouldn't find very many.
32:58
Speaker 1: But if you have, you would get burned to a crisp.
33:02
Speaker 1: You would not get burned to a crisp because there
33:04
Speaker 1: are hardly any particles out there, And you can ask
33:06
Speaker 1: a physicists like, hey, what's the temperature out here, and
33:08
Speaker 1: they'd be like, m, it's a hundred million degrees celsius.
33:11
Speaker 1: But if you got dropped there without a space suit,
33:13
Speaker 1: you would not get burned. You would freeze. I see
33:17
Speaker 1: there there are a lot of hot pins out there
33:20
Speaker 1: in that space, but if you stood there, you wouldn't.
33:23
Speaker 1: You would hardly feel them exactly. They're there, and they're
33:25
Speaker 1: really hot, Yeah, they wouldn't. You wouldn't get hit by
33:28
Speaker 1: enough of them to keep you warm, right, you would lose.
33:29
Speaker 1: You would radiate all your heat into the pretty empty
33:33
Speaker 1: space and freeze into a block a block of ice, right,
33:36
Speaker 1: And you wouldn't get warmed up by the hundred million
33:39
Speaker 1: degrees celsius plasma that surrounds you because it's hardly any
33:43
Speaker 1: part of hitting you, all right, see, but the average
33:47
Speaker 1: speed of those few that are there is a lot
33:50
Speaker 1: there wouldn't exactly just wouldn't be enough to really burn
33:53
Speaker 1: you or feel them exactly. Yeah. Wow. Right, so it's
33:57
Speaker 1: zoom back to Earth because it turns out that here
33:59
Speaker 1: on Earth we've created some pretty crazy hot stuff. And
34:02
Speaker 1: that's not just your frying pan. But when we collide
34:06
Speaker 1: particles at the Large Hadron Collider, we very briefly create
34:09
Speaker 1: a situation where the particles have a huge amount of energy. Okay,
34:13
Speaker 1: but again it's not about energy you're saying. You create
34:15
Speaker 1: a situation where the particles are moving really really really fast. Yeah,
34:19
Speaker 1: the particles are moving really really really fast. But you
34:21
Speaker 1: don't really consider the temperature of a particle, right, So
34:24
Speaker 1: if you say, like, well, what's the temperature of a
34:26
Speaker 1: proton zooming around the Large Hadron Collider, we can't talk
34:29
Speaker 1: about the temperature of one particle. But sometimes in the
34:32
Speaker 1: Large Hadron Collider, we don't just collide protons. We take
34:35
Speaker 1: big stuff like the nucleus of a gold atom or
34:38
Speaker 1: lid atom, and we smash those together, and the reason
34:42
Speaker 1: is that they're trying to break up the matter and
34:44
Speaker 1: create this this condition that they think existed in the
34:46
Speaker 1: early universe. It's called the cork gluon plasma. So when
34:49
Speaker 1: you break the proton up and the corks and the
34:51
Speaker 1: gluons have so much energy that they're not bound anymore.
34:55
Speaker 1: They're just like floating around free. So you smash enough
34:58
Speaker 1: particles together so you know, lead and uh and gold
35:01
Speaker 1: atoms have hundreds of protons and neutrons in them. Then
35:04
Speaker 1: very briefly you create this thing which they think is
35:07
Speaker 1: in equilibrium, so you can define the temperature. It's like,
35:10
Speaker 1: you know, bounced around for a few you know, bill
35:13
Speaker 1: of seconds, and this thing they say, he gets to
35:15
Speaker 1: five and a half trillion degrees celsius trillion with the
35:19
Speaker 1: T trillion with the T exactly, Like that's a big number. Well,
35:24
Speaker 1: let's get into now the hottest the absolute champion most
35:28
Speaker 1: hot thing in the universe. But first let's take a
35:31
Speaker 1: quick break. All right, Daniel, here we go. Here's the
35:46
Speaker 1: answer to the question that we post at the beginning.
35:48
Speaker 1: The hottest things in the universe, the absolute extreme most
35:52
Speaker 1: hot things in the universe exactly, and here I think
35:55
Speaker 1: we got to give some credit to the scientist for
35:58
Speaker 1: coming up with names. Is you know, on this podcast
36:00
Speaker 1: we're always poking fund of scientists for naming things in
36:03
Speaker 1: a silly way. I think they did a great job here.
36:05
Speaker 1: Because the maximum the temperature in the universe, the condition
36:08
Speaker 1: of something being at the absolute maximum temperature. They call
36:11
Speaker 1: it absolute hot, which I think is pretty cool. You mean, wait,
36:16
Speaker 1: you're saying that there is a maximum temperature in the universe.
36:20
Speaker 1: That's right, there is a maximum temperature, and it's a
36:23
Speaker 1: crazy number, and it's kind of a hard thing to
36:26
Speaker 1: think about, Like why would there be a maximum temperature?
36:28
Speaker 1: You might think you can give an infinite amount of
36:31
Speaker 1: energy to a particle, and that's true, right, Like you
36:33
Speaker 1: take a single particle, you can dumb as much energy
36:35
Speaker 1: as you want into it. You know, there's a state
36:37
Speaker 1: of light issue. But we're not talking just about speed.
36:39
Speaker 1: We're talking about the energy of the particles. No limit
36:41
Speaker 1: to how much energy you can give a particle. But
36:44
Speaker 1: now we're talking about a system of particles, so we're
36:46
Speaker 1: talking about energy density. What happens when a bunch of
36:49
Speaker 1: particles have a huge amount of energy. Well? Gravity, right, gravity?
36:54
Speaker 1: Remember bends space, and it bends space when you have
36:57
Speaker 1: particles with mass, but also it bends space and you
37:00
Speaker 1: have energy density. Alright, gravity is not just something that
37:03
Speaker 1: responds to mass, a response to energy. So what happens
37:07
Speaker 1: if you pour too much energy into a little blob
37:10
Speaker 1: of space? Black hole? What? Yes, black hole? Right, there's
37:14
Speaker 1: a maximum amount of energy you can have in a
37:16
Speaker 1: certain in a volume of space. More energy than that
37:20
Speaker 1: turns into a black hole. So you can't heat something
37:23
Speaker 1: up past that. Wait to wait wait wait wait wait wait,
37:25
Speaker 1: So the I mean I would think that the maximum
37:27
Speaker 1: temperature in the possible theoretically is when you have a
37:31
Speaker 1: box of particles and every particle in it is moving
37:35
Speaker 1: pretty much at the speed of light. Because you know,
37:37
Speaker 1: temperature we said before is related to how fast things
37:39
Speaker 1: are moving. So what if every particle was moving close
37:42
Speaker 1: to the speed of light. You're saying that's not possible
37:44
Speaker 1: or we wouldn't even get there. That's possible, it's just
37:47
Speaker 1: not even that very hot because remember the speed speed
37:50
Speaker 1: is not the limitation, right, Like, you can get particles
37:53
Speaker 1: up to the speed of light without even having that
37:55
Speaker 1: much energy. Okay, and not bad to the speed of light,
37:58
Speaker 1: just like close to the speed of light. But remember,
38:00
Speaker 1: as you dump more energy into these particles, their speed
38:02
Speaker 1: doesn't go up very much. That's why temperature is not
38:05
Speaker 1: just the speed of the particles, it's their energy. Remember,
38:08
Speaker 1: relativity separate speed and energy, and there's no limit to
38:11
Speaker 1: how much energy you can put into an individual particles.
38:13
Speaker 1: You have your box. You can keep pumping energy into
38:16
Speaker 1: those particles. Their speed doesn't go very much, but their
38:18
Speaker 1: energy increases. But you keep doing it. Eventually your box
38:21
Speaker 1: turns into a black hole. Oh what point does it
38:24
Speaker 1: turn into a black hole? Are you ready for the number?
38:26
Speaker 1: All right? For here's absolute hot is a billion trillion
38:31
Speaker 1: trillion degrees celsius, billion trillion trillion degrees. Is there a
38:35
Speaker 1: name for that, or it's called absolute hot, or more
38:39
Speaker 1: technically it's called the plunk temperature. But wait, is it
38:42
Speaker 1: a billion trillion trillion degrees or is it you know,
38:45
Speaker 1: two point seventy three or four? It's just a round number.
38:48
Speaker 1: Oh no, it's not exactly a billion trillion trillion degrees.
38:51
Speaker 1: But the number, if you want to know the exact value,
38:54
Speaker 1: is one point four one six times ten to the
38:58
Speaker 1: thirty two kelvin. All right, that's like a hundred and
39:02
Speaker 1: forty two million yadda kelvin's or a hundred and forty
39:07
Speaker 1: two million quadrillion degrees kelvin. It's pretty hot. It's a
39:12
Speaker 1: lot of YadA, it's a it's a lot of And
39:17
Speaker 1: then you might ask like, well, you know, is that possible,
39:20
Speaker 1: like that ever existed in the universe, And you know,
39:23
Speaker 1: we don't think it's happening right now. There's nowhere in
39:25
Speaker 1: the universe that's absolute hot right now. Um, but we
39:30
Speaker 1: think that just after the Big Bang, like you know,
39:32
Speaker 1: this this crazy moment when the universe was inflating, right
39:36
Speaker 1: when they expanded really really rapidly. We think that just
39:39
Speaker 1: before that that the universe was at the plunk temperature,
39:42
Speaker 1: and that uh, you know, that's the absolute hottest moment
39:46
Speaker 1: in the history of the universe. But there's a lot
39:49
Speaker 1: of handwaving there because we really don't understand what happened
39:52
Speaker 1: during the Big Bang and why did it cause inflation
39:55
Speaker 1: and not just all collapse into a black hole. Anyway,
39:57
Speaker 1: there's a lot of questions about that, Okay, there is.
40:00
Speaker 1: So the main point is that there is an absolute
40:02
Speaker 1: like if I take a if I heat something in
40:04
Speaker 1: my frying pine forever. At some point it's gonna get
40:07
Speaker 1: super hot, and at some point it's it's just gonna
40:11
Speaker 1: turn into a black hole and it can't get any
40:13
Speaker 1: harder or what. You cannot create a black hole on
40:16
Speaker 1: your stovetop working, I'm sorry, No matter how long you
40:18
Speaker 1: cook that bacon, it'll get black, it'll turn into charcoal,
40:21
Speaker 1: not a black hole. But if you had like laser
40:24
Speaker 1: beams and all sorts of stuff, and you could like
40:26
Speaker 1: pour energy into a tiny area, then in principle, you
40:30
Speaker 1: could create a black hole. Yes, well, how to First
40:32
Speaker 1: of all, how do you know I don't have lasers
40:33
Speaker 1: in my kitchen already? You're an impressive chef, and you're right.
40:37
Speaker 1: I shouldn't have ruled anything out. I issue formal apology. Um,
40:42
Speaker 1: But I mean basically, if you heat something out long
40:44
Speaker 1: enough and you put enough energy into it, at some
40:47
Speaker 1: point you're saying it's going to turn into a black
40:49
Speaker 1: hole and then it can't get any harder or what happens.
40:51
Speaker 1: Then we don't know what happens then, right, because then
40:53
Speaker 1: it turns into like quantum gravity questions and we just
40:56
Speaker 1: don't even have a theory, so we don't I mean
40:58
Speaker 1: we don't know what's happening inside a black hole. If
41:00
Speaker 1: you poor energy into a black hole, we don't know
41:02
Speaker 1: what happens. Um. Basically, it's a huge question mark. So
41:06
Speaker 1: it's sort of a breakdown of the definition of temperature.
41:08
Speaker 1: Like stuff definitely happens, things get crazy, or the universe
41:11
Speaker 1: gets weirder, but it's not according to our definition of temperature.
41:15
Speaker 1: Does that the number we define as temperature doesn't go
41:18
Speaker 1: up anymore? So maybe calling it absolute hot is a
41:22
Speaker 1: little premature, right because it really you've called it super
41:27
Speaker 1: duper crazy hot, yeah, or like super duper I don't
41:30
Speaker 1: know what happens after this hot is really sort of
41:33
Speaker 1: more accurate, right, But we should have called it Jog's
41:36
Speaker 1: frying pan hot. Yeah, there you go. Jore is black
41:41
Speaker 1: bacon hot exactly exactly. Okay, So that's a lot um
41:48
Speaker 1: And you're saying that happened at the beginning of the universe, right,
41:51
Speaker 1: like it. So the hottest thing in the universe ever
41:53
Speaker 1: is the Big Band. Just once again, that's the answer
41:57
Speaker 1: for everything. The hottest thing in the universe is the
42:00
Speaker 1: Big Bang, yes, as far as we know. Okay, but
42:02
Speaker 1: that happened a while ago. But if we looked at
42:04
Speaker 1: the universe. Now, what what would you say is the
42:06
Speaker 1: hottest thing, Well, the hottest thing recently is this cork
42:09
Speaker 1: glue on plasma we create the at the large hage
42:11
Speaker 1: On collider. Right, that's five point five trillion degrees celsius.
42:15
Speaker 1: That's hotter than we think, you know, most things in
42:17
Speaker 1: the universe. Um, otherwise, like the inside of a neutron
42:21
Speaker 1: star we think is about a hundred trillion degrees celsius,
42:25
Speaker 1: and that's probably the otherwise hottest thing in the universe,
42:28
Speaker 1: like on a day to day basis, because you know,
42:30
Speaker 1: the large Hagron collider, these things exist for ten to
42:32
Speaker 1: the might is twenty three seconds, so they don't really
42:34
Speaker 1: stick around very long. But the intside of a neutron
42:36
Speaker 1: star is super hot and very stable at a hundred
42:39
Speaker 1: trillion degrees celsius. Wow, a cool and chili hundred trillion celsius,
42:44
Speaker 1: which is what like fifty fahrenheit or how much is that?
42:48
Speaker 1: I have no concept something like that, something like that. Yeah, exactly. Um,
42:53
Speaker 1: don't pack any jackets. I don't think you'll need them
42:56
Speaker 1: because you won't be alive. That's right, Okay, cool, So okay,
43:03
Speaker 1: so that's the hottest thing in the universe. It's the
43:05
Speaker 1: big Bang ever and it's the inside of an intrance
43:09
Speaker 1: star out there possibly right now. That's right, that is
43:12
Speaker 1: the hottest place in the universe right now. All right, Well,
43:16
Speaker 1: stay tuned for future episodes in our Extreme Physics series
43:21
Speaker 1: will be tackling also the brightest thing in the universe
43:24
Speaker 1: and maybe also the densest thing in the universe. We
43:26
Speaker 1: should also tackle like the funniest thing in the universe.
43:29
Speaker 1: That's obviously that's this podcast like done. Yeah, but speaking
43:35
Speaker 1: of funny things, yea, I have a request for you
43:37
Speaker 1: from a listener. All right, we have a listener in
43:40
Speaker 1: New Zealand who's a huge fan of limericks and often
43:43
Speaker 1: tells physics limericks to his class of ten and eleven
43:47
Speaker 1: year olds where he teaches in New Zealand. Well, I
43:50
Speaker 1: said a limerick in our podcast a few weeks ago.
43:52
Speaker 1: We were talking about tacking on and uh, he noticed
43:56
Speaker 1: that you didn't laugh at my limerick, so he sent
43:58
Speaker 1: me a different physics rick to see if we can
44:01
Speaker 1: make you chuckle. All right, So here you go, you ready,
44:03
Speaker 1: right right, all right? Hit me. There was a physicist
44:06
Speaker 1: called Joe who wanted the whole world to know that
44:10
Speaker 1: those stars that we say are far far away are
44:13
Speaker 1: actually long long ago. Nice. That's cute. That's pretty cool. Yeah,
44:18
Speaker 1: that's pretty cute. Thank you Ryan. Let's say with Jorge,
44:22
Speaker 1: I thought it was somehow related to me. No. Um, Well,
44:26
Speaker 1: let's ask our our listener to send in one tailor
44:29
Speaker 1: for you. But that's for Isaac Garmet from Coromandel, New Zealand.
44:34
Speaker 1: So thanks for sending that in. Yeah. Great, And if
44:37
Speaker 1: you have any other limericks or ideas or questions for us,
44:40
Speaker 1: maybe a banana related limerick for Jorge, send them in
44:43
Speaker 1: two feedback at Daniel and Jorge dot com. We love
44:46
Speaker 1: your emails. Great, thanks for listening and we hope you
44:49
Speaker 1: enjoyed this. Tune in next time the hot person you. Yeah,
45:02
Speaker 1: if you still have a question after listening to all
45:05
Speaker 1: these explanations, please drop us a line. We'd love to
45:08
Speaker 1: hear from you. You can find us at Facebook, Twitter,
45:10
Speaker 1: and Instagram at Daniel and Jorge that's one word, or
45:14
Speaker 1: email us at feedback at Daniel and Jorge dot com.
45:18
Speaker 1: Thanks for listening, and remember that Daniel and Jorge explain,
45:21
Speaker 1: the universe is a production of I heart Radio. For
45:24
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45:27
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