SIO433: The Robot at the End of the Universe

Transcript

This transcript was generated automatically and may contain errors — the audio is the record.

0:00:16 Thomas: And welcome to Serious Inquiries Only. This is episode 433. I'm your host, Thomas Smith, and today I've got a bit of a different one for you. It's astrophysicist Dr. Brian Gillis, but we thought it would be fun to do something that I used to do over on Philosophers in Space. Great show, still going on with Aaron and Callie over there. But we used to is take a work of sci-fi, discuss it, discuss what happened, you know, give a little bit of the plot and all that.

And then talk about the themes. And for was one that I've wanted to do for a long time because it's so fascinating and it's so directly physics related. Dr. Brian Gillis was kind enough to read it, check it out. He loved it as well. So that's what we're going to do. We're going to take you through a Ted Chiang called Exhalation. Now, I think you should just go read it first. It's on Audible and all the things. It's freely available if you Google. Not very long.

It's really good. But if you don't want to, it's really not a big deal. Nothing that matters if you spoil it, really. It's just a good little journey to go on. So Exhalation by Ted Chiang is the name of the short story. We're going to take you through it. And then we're going to learn about and the end of the universe. I almost said world, but that's too small.

The end of the entire universe, the heat death of the universe, all that stuff, how it's related to entropy. Is there any way we can avoid it? Can we cheat it? We find a way to say no to entropy if we just with our bootstraps or something? I don't know. All those questions, questions much more answered by Dr. Brian Gillis. As you'd like to avoid the ad break coming right now, go to patreon.com/seriouspod and join, get all the benefits, the extras.

Oh, House was so fun last month. The Seriously Awful Movies episode was another House episode. I love it so much. It's it's my favorite thing to do with a real doctor. You don't want to miss it. It's up there on the Patreon. Check it out. Thanks so much to those patrons who make the show happen. All right, this break, we'll get to Exhalation with Dr. Brian Gillis. Welcome back. Everyone's favorite astrophysicist, Dr. Brian Gillis. How are you doing?

0:02:18 Bryan: Doing well, Thomas. Thank you. How are you today? Yeah.

0:02:20 Thomas: Doing well. It I was so fun to get to reread a story. Boy, reread Ted Chiang's short story, Exhalation, as part of the broader collection called Exhalation, I believe the whole thing is called that. And such a cool little short story and it's a great chance to talk about some science. And so it's almost a little bit of a scientists in space, like a philosophers in space -esque, you kind of thing, but more a science angle. So I'm really excited to do it.

0:02:45 Bryan: This was a great story. Uh, yeah, it was around a year ago now. You'd ask me to get this collection of stories to think about what we could do episodes on and we're just getting to it now. That's How many other ideas we've had in the meantime. Oh,

0:02:53 Thomas: Oh my God, you're right. That's I completely forgot. Yeah, because it's, it's, uh, it's so good. I love Ted Chiang. I just, seriously, if anyone, I am not like a sci -fi knowledgeable guy. I know everybody knows more than I do about everything. But when it comes to Ted Chiang, I know what I love and I effing love, oh wait, this is SIO, I cursed on this one, I fucking love Ted Chang I I've almost everything he did on Audible.

I think I actually should check back, maybe there's more stuff now, but every single story is good. I like can't think of a one that wasn't good. And it's so satisfying to read someone like a really just talented author that does this thing that he does, which is like incorporates, you kind of scientific concepts into stories in a way that's, that's what really, I think it makes it so good.

As I don't believe it matters much if you are are into the science part of it, like you have to be a good storyteller. I just by itself, like I think a lot of sci -fi tries to bail itself out with just the sci -Fi part.

I, and really think the that sci fi that sets itself apart is just also just good, and it also has these really cool scientific, I, not insights, but like explorations, you, you know, of these ideas that he, he'll often take, like, okay, but what if it, what if there's a world and it's, you, world, but different in this way, or that, you know, it's just, he's so good at it. I absolutely

0:04:13 Thomas: Love Ted Chiang.

0:04:13 Bryan: And some of those ones, like thinking through, in the collection, there's this other story that's stuck in my memory, which was, what if young Earth creationism was actually true? What would that world really look like? Was that a fascinating one. And it was things like trees that were old enough stopped having rings at a certain point because God in this world wasn't trying to fool anyone.

0:04:24 Thomas: Oh yeah. Right. Yeah.

0:04:38 Bryan: And so he didn't put fake rings inside trees. They just had, you know, smooth tree -ness inside when he created them, but developed rings after that.

0:04:38 Thomas: I love that one. Yeah. So fascinating. So just starting off with a heavy recommendation for Ted Chiang, my absolute favorite sci-fi author. This story, it one of those ones that stuck in my mind. Listened I to the audio book a few years back and I think, remember if I told you on air or off air, but I actually remembered like I was listening to this story, I could remember the place in Breath of the Wild that I was. I was in the Goron City or whatever. And I just remember, you know, those little things stick in your mind. I have a lot lot of pandemic memories that are like that.

0:04:49 Bryan: Yeah. Oh, yeah, that happens too. Like, I very often will pair playing a game with listening to music or a podcast or something if game doesn't have too much text. And there are a lot of times I'll listen to something very interesting for the first time and it'll stick in my mind paired with exactly where I am in that video game and always come to mind at the same time. It's very fascinating the way human memory works that way. Actually is applicable as we're going to be talking about robot memory here.

0:05:22 Thomas: Yeah. Yeah, yeah, exactly. And little bit. Yeah. And this book, love this whole collection. But Exhalation in particular, it stuck in my mind for some reason because it just had that fascinating tone of a first person narrative of like a scientist making discoveries, which is always going to be interesting to me. Like I just, you like that 19th century kind of scientific tone where one person is still making. He's making all these discoveries that doesn't happen so much anymore. And there's something so cool about that sort of narrative, like you're reading a scientific journal of someone who's made these cool discoveries. And he does that, but it's for a, I guess we would say a robot, right? All written from a different perspective and really immerses you in this different world that you piece together as you go. And it's this it like story of discovery of what the world is made of and what the brains are made of this particular robot. I don't know, species, I guess you would say.

0:06:01 Bryan: Yeah. Yeah. Yeah. Yeah.

0:06:38 Thomas: And it unfolds in a, in that like, it really just grabbed me because it's just this also, there's a bit of tragedy to it and it's so good. These robots, instead scientists don't know that much about the internal workings of them because they don't really die. Like, they're not, they DON'T have the same fragility that we do. And They when they die, it's usually something catastrophic that kind of destroys, you all remains.

0:06:54 Bryan: Yeah. Yeah.

0:07:01 Thomas: So, so don't know much about...

0:07:01 Bryan: They explode when they die, which makes figuring out anything about how their internal working is pretty difficult because you're just analyzing the wreckage. Though there is one exception to that. If they die because they run out of breath, then they die kind of calmly or relatively peacefully.

0:07:11 Thomas: Yeah. Yeah.

0:07:21 Thomas: Mean the beginning is kind of building the world for you and they talks about um, lungs that change out, you know, almost like gas tanks, kind of energy tanks, and the of the crucial information about this robotic uh is that uh, it's all dependent on air, on, I don't remember if it's actually oxygen, I think I think, yeah.

0:07:28 Bryan: No, argon, actually.

0:07:39 Thomas: Yeah, the robot calls it air, yeah.

0:07:40 Bryan: So of the elements in our atmosphere. It's about 1% of our atmosphere, and I by the fact that they call their air argon that it's the most common element there, if not almost entirely argon. So for those who don't know much about chemistry. Argon is a basically inert element. It nothing.

0:07:47 Thomas: What Does Okay.

0:08:05 Bryan: It's very difficult to get it to engage in any chemical reaction. Yeah. So part of a group of elements called the noble gases, which also include helium, neon, and basically every element that ends with on plus helium.

0:08:06 Thomas: It's Like stable. Okay. Are They all on the left side of the thing, The Right side of thing, yeah, the Periodic table.

0:08:22 Bryan: Right side. Yeah, they're often separated off because they all share the property of having very few, if any, chemical reactions.

0:08:25 Thomas: Yeah, yeah. I bet they're snobby, I bet they don't like, I bet look down on other elements, you know. Don't you get that feeling like?

0:08:38 Bryan: Well, reason is they've got all of the electrons they need and exactly as many as they need. So they look down on everyone else because everyone else either needs a few extra or has too many. The noble gases, they've got it made.

0:08:43 Thomas: Yeah. Yeah, that's right.

0:08:54 Bryan: Robots, are intelligent with human -like intelligence. And we don't have anything like that, although we're getting pretty good at mimicking it. So This isn't exactly something real. I don't think it's even a metaphor or analogy for something thing, um, would probably be the biggest clue. The other clue we have is that their universe is surrounded by a big chromium dome, uh-

0:09:18 Thomas: And- Yeah, I love it, that's toward the end, he- the- the robot speculates that like the universe, it could be, it's like the multiverse, but for this- that's why I love about this, it's so- many of those little comparisons where- the robot's like, "What if there are other you in the vast chromium," and you- know, maybe someday another uh of beings will like tunnel their way to us. But anyway, the- beginning insights are mainly about, the you lack of knowledge of anatomy due to those reasons. You also get a picture of like, you know, again, they're dependent on these lungs. They change out lungs like they're gas tanks, kind of extra batteries in a way.

0:09:28 Bryan: Yeah. Yeah. Yeah. Okay.

0:09:51 Bryan: Describes air as kind core of life. And what's important to him is the daily ritual of the filling stations. Oh, can think about it like going coffee in the morning and hanging out with other people, except this is absolutely core to their life. So they- know that they require air to live. If they don't get their lungs either replaced or filled up, they will die from going out of breath. So what they do is they go to filling stations where you can connect up lungs, lungs, to a big reservoir of gas deep underground, if you can. You hang around for a while, while it's filling up, and just talk with other people who are there, catch up with things. And our loves this as part of his life. He considers it one of the core of his day, hanging around the filling stations and catching up with everyone. And-

0:10:09 Thomas: Yeah, it's that little world building that makes it fun. And the inciting incident of story this is that there's a ritual that they perform, some sort of, it's almost like a speech kind of. Yeah, It's something where It's a speech and apparently It's set to an exact hour is like, because again, this is a robotic species. So their ways of, you measuring things and doing things is going to be different and interesting ways. And the importance of this ceremony, I guess, is that it's precise in its timing. It lasts exactly an hour. And then it's reported that like, particular town or whatever, the bell, like the clock tower, went off slightly before the ceremony was done. And it's like, well, shoot, maybe something

0:10:56 Bryan: A New Year's festival. Yeah.

0:11:27 Bryan: Yeah,

0:11:28 Thomas: Happened. Maybe a mistake happened. Maybe the clock tower is out of sync or out of whack or whatever. And

0:11:28 Bryan: Yeah. Like, yeah, there's a bit of investigation of this. This happened in another town, too. It wasn't just your storyteller failing.

0:11:39 Thomas: And then finally, once they hear that it happened in yet a third place where the clock tower is based on different technology, then then this guy who I guess is, you know, seems to be like an anatomist, I guess, is really worried by it and is and investigate and talks about the fact that like not much is known about anatomy. There are different theories of how their brains work. I love stuff like that where That's what makes good sci -fi. I mean, written like about different theories that also end up being wrong about this pretend world. I just love that kind of thing.

0:11:40 Bryan: Yeah. Yeah, yeah. Yeah? Yeah. Oh, yeah they do that with a is another thing that comes up in this, although it isn't the core focus. It's one thing a lot of people are really interested in and that they noticed they had forgotten some things. They have a memory that lasts a couple hundred years or so, but none of them can remember any further back than that. So they don't know how they were create or just zapped into being or evolved somehow. They want to know more about their history. And there's hope that maybe the memories are still in their minds and just inaccessible.

0:12:41 Thomas: Yeah. If they figured out how brains worked in their world, they could perhaps learn. I Love that part, too, because I believe the robot says that robots can can remember about a hundred years and they have written record going back 200 years. And so they know they were around then. And also it's, it's again, it'S not like a species that reproduces like we do. I guess they just tend to hang around. I don't know if there's a fixed number of them or what.

0:12:57 Bryan: Yeah.

0:13:06 Bryan: Be slowly declining just from the random accidents.

0:13:08 Thomas: Yeah. Yeah, but I, it doesn't, we don't get any indication that there's any way new, robots new are made. And, so it's Really, I love that little setup too of like, like, yeah, you know, people are really interested in the theory of how this memory works because, you know, one theory is that, be you transient and the memories, once they're lost, they're gone forever. And another theory is like, no, maybe they're still in there somewhere. And so a lot of robot scientists in this world are hoping one day they can unlock sort of how to translate or figure out how to access that so it was a really interesting concept so that they could go in their own brains to figure out what they were doing before 200 years ago, essentially. It's really interesting.

0:13:13 Bryan: No, it doesn't sound like that. Yeah. Yeah, yeah, I guess they were kind of thinking maybe the memory's like a filing cabinet and you keep writing new things down and putting it at the front and eventually the things at the back are too far back for you to reach. But maybe if we understood how the brain worked we could reach in there, get the stuff at the bank out, and then and translate it, and figure out what our early memories are.

0:13:56 Thomas: And the other piece of data we have is that when a robot to die by losing oxygen, like not getting lungs in time, when they reconnect it to a of lungs, the memories are gone. I actually don't know if it doesn't matter, but I don't know if that means that it's just like a new person or if that can't really function.

0:14:07 Bryan: Yeah.

0:14:22 Thomas: I'm Not sure right

0:14:22 Bryan: Well, it's kind of implied that they don't even come back to life. Talks about it for a sentence or so. I said he, it should probably be they or it even.

0:14:26 Thomas: I Know I keep saying it's, yeah, sometimes I say he isn't Ted Chang writing it but yeah, yeah.

0:14:34 Bryan: Yeah yeah, it's all written in first person And I'm not sure if he ever talks about any individuals. I'd have to double check what pronouns are used. Probably they. Yeah, talk about individuals that have the lunch turned on, they're described to be like empty Shells. So it's kind of like, uh, there isn't even the active mind in there, they aren't doing anything, they appear to be on, there's just no there there. So, so that would seem to imply that, uh, something active that needs to be going on for least the conscious brain. Maybe the memories could have been hard at that point. To take an analogy of a computer, it has, broadly speaking, two types of memory.

There's what we call RAM, or random access memory, which only exists as long as it's turned on. It relies on an active current going through something. And then there's harder stored memory, which, for instance, could be engraved into a disk which is spun to read it in the old-fashioned. We have new technologies, but you have that kind of dichotomy.

And so it would make sense that the conscious mind might be on the quick, easy-to-access memory, and maybe memories could be stored in a more permanent way that takes a bit of time, but they just don't know. One's willing to open up someone who's living, and it's really hard to analyze.

Got the issue of, of, okay, something weird is going on with time, the narrator thinks, oh, it be a problem with us rather than, like, what if it's a bug or mistake in all of our designs that's causing us to slow down?

So with this reason and with, all you the other thoughts about maybe we can figure out memories as well, he sets up an experiment that he's been thinking about for a a while, which is basically performing brain surgery on himself to figure out how his brain works.

0:14:51 Thomas: I Yeah.

0:16:39 Bryan: And is something that really only works with a robot. You can't really imagine any creature that feels pain doing this. Just a fascinating description of how he does a room with a lot of like arms that he attaches to the arms in front of him and assemblages a mirror so that he can look at his head from behind, and so he attaches his arms to extenders that wrap around and come in behind him so he can reach around and lift off the back of his own head. And while he's doing this, he figures, you know, there's probably a a good chance I'll die from this. So I'm going to invite one of my friends over in a week. And in case I die, they'll find me.

0:16:42 Thomas: Yeah. Yeah.

0:17:16 Thomas: He Sets Up enough Like lungs, like just like daisy Chains extra lungs to last, last six days, and then he also plans on having someone visit him just in case, yeah, it too, because he talks about like, because he's a robot and he's using kind of, uh, and stuff like that, it's like robot, oh, almost becomes that entire extended setup.

0:17:20 Bryan: Yeah, Yeah.

0:17:34 Thomas: Which I think is fascinating that even happens with humans, I believe, like, if brains have kind of a mental map of our bodies. And if You, you know, that's why the phantom limb kind of thing happens. And it can go in the other way, where you start to feel like other things are an extension of your, your body.

And this is really interesting thought expressed there, but it, yeah, turns out to be that key, key insight here is that the way the brain works is kind of neither the theories really that we discussed, it's, is these little gold leaves that they, they at least knew about that, like, they had seen that those existed, but the way that these robots are functioning is it's through the constant sort of flow of air through these gold leaves, in a way that means the minute the air stops, it, in the same way that, you know, we seem to be our entire mental brain, you pattern, know, at a given time, and, uh, possibly not dependent on, um, the medium you The substrate chauvinism, robot makes that same discovery, that like, oh, not as though the memories are kind of in the gold leaves per se, it's like the whole functioning, functioning and the pattern of airflow of constant little airflow between and among these little gold leaves is what actually makes a person in this world, and how does the robot make the discovery about the crucial time, you know, air pressure differentiation thing, I actually am not quite remembering how he does that.

0:17:41 Bryan: Yeah.

0:18:25 Bryan: Substrate.

0:18:50 Bryan: Think it's just on a close inspection of how the central processing unit, so to speak, of their brain works. Uh, they're looking inside and they're just thinking about the physics of it, all that happens if the air is, uh, more slowly through it, and if you think about that way, if the air is blowing more slowly, then all of the changes in state will propagate more Slowly, uh, out the brain. And I think it's from that that they come up with the insight that something happening with the pressure to slow things down. The way their lungs work is there is a big pressure reservoir underground, which might be losing pressure over time, but their lungs are always filled up to the same fixed pressure. So that shouldn't be running out. And then he starts to think, well, it's the pressure difference. We know there's air outside as well.

And if the lungs are always the same pressure, then what if the air outside is increasing in pressure over time? Starts to think about this. Way the, they the world is that it's surrounded by giant chromium walls that appear to go up forever. And so they think, what if these walls are actually part of a dome, and we're in an enclosed universe, then the air would have nowhere to go, would steadily build up pressure outside, as

0:19:18 Thomas: It's

0:20:21 Bryan: It runs through our minds, and that would explain why it goes more slowly, because the rate of flow is proportional to the difference in pressure. What's interesting here that isn't in the story is that everyone seems to more or less just accept the science of this, which is absolutely nothing like because we still can't convince people of global warming.

0:20:21 Thomas: That's What it Is Yeah Yeah It's a different world, it's different universe, yeah. Then Again, so the robot does describe, so basically this robot shares the news that it's essentially their version of a kind of climate Change but also Just entropy and heat death of the universe, in a way, which is eventually this pressure is going to equalize, but the pressure between, I guess, this underground reserve and the place where they live, and once it pressurizes, all life and movement in their universe will stop.

And there's interesting writing about like the ways they can compensate for that, and the does describe, there's like a movement of robots that think there's a way to fix it, and So they construct this, like, oh, there's this special air tank we can do that will actually stop this, but then you, it's pointed out that, of, like, in the same way, there's, there's just no such thing as you cheating the conservation of energy or momentum or whatever, there's the air pressure is still getting, uh, in, in subtle ways, you, you know, so there's no way to really, there's no free lunch, as a lot of science teachers have said.

0:20:54 Bryan: Yeah. Yeah, yeah, yeah. This a group called Reversalists. They of skip over the part of proving to people it is a problem. They They seem to accept it, but then they go to, okay, but we can fix the problem. So the pressure out here is getting too high. So we just need to reverse the process, take the air out here, cram it back into a smaller container and just, you lock it up somewhere. And then we can keep having the pressure differential. And they show, they come up with devices. Yeah, we can do this. We can compress air. But then others point out to them, well, yeah, you're doing that, but you have to use up air pressure in the first place to do that.

0:21:48 Thomas: Right, yeah. Mm -hmm. Yeah.

0:22:20 Bryan: And if we very carefully figure out how much you're using up versus how much you're getting rid of, you're always using up a bit more. And the reversalists are like, okay, well, that's just an efficiency problem. We'll get more efficient. They keep working at it, figuring out other ways, but they seem likely to come on to anything. And is being written at the time that the reversalist are are still trying to figure it out, but the narrator seems to be convinced that they aren't going to be able to. And the narrator's in the position of just trying to go from the position of, I could live forever. I might not remember more than a hundred years or so, but as long as I don't get into an accident or something, I'll live forever, to shifting to, oh, this is all going to stop sometime.

0:22:31 Thomas: Mm hmm.

0:23:05 Thomas: Yeah, yeah, they, and not just this robot, but all robots in that little world. It's this tragic inevitability, and robot is musing on, the robot has a little leaving kind of a record for like, hey, maybe someday, as I started to say earlier, or another maybe there's other pockets of whatever in this vast chromium and maybe they'll find us and they'll be able to see this written record and you know and then then the robot is saying like yeah but but you are probably susceptible to the same principle that like someday you pressure will equalize everywhere and there's that's where maybe Ted Chang takes a little bit of uh of just this This robot kind out that this is is some entropy. Basically, this is like some principle of the entire universe. And I feel like that was a little bit quick and shortcut, but that's OK. It's a short story.

0:23:11 Bryan: Yeah. Yeah. It's idea I get is that this is written for people who might come and discover the civilization and want to learn about it.

0:23:54 Thomas: Yeah, exactly.

0:24:03 Bryan: So which includes what they liked about life, process of discovering it, how they're handling it or not handling it, and then the message he wants to, or they want to give to others.

0:24:18 Thomas: Love it, because it always, time I thought about the whole you entropy, heat death of the universe thing, it always makes me think of that, like, probably very unscientific thought of like, well, but I don't get it, like, if you the ever -expanding universe and all that stuff, but what if you were there, like, what couldn't you stop it somehow? You know, like, I'm always like, couldn't you, isn't there some way that, that there's got to be some way we could preserve, uh, what, and I guess it wouldn't be preserve entropy, I never remember which way, that direction that goes, but like, is is this inevitable yeah like is the, is the increase in entropy be inevitable, is there no way to just somehow create like our little entropy-free zone that we can maintain? Hmm.

0:24:45 Bryan: Stop it from increasing, yeah. Yeah.

0:24:57 Bryan: I like about this story is it presents a simplified case of and that really you only have pressure, and the equalization of pressure. In reality, we've got pressure, temperature, which is closely related to pressure. We've got all sorts of other forms of energy that things can take, makes which it a lot more difficult to understand. And this Story does a great job of illustrating entropy through boiling it down to one single mechanic that enforces it. So I think it's really great to use this as a leaping off point to discuss basically what you just said, Thomas, couldn't we stop it? The way I think is best to frame it is to talk about, uh, laws of thermodynamics, uh, how familiar are you with the, what's called the Laws of Thermodynamics, in capital letters, Thomas? Yeah.

0:25:18 Thomas: Yeah I'm mainly familiar with whatever one the creationists use to try to say evolution can't exist because, like, there's information is created in a way, and I have, have no idea if that's at all representing an actual, you know, like, an telling of whatever this law of third order dynamics is, because actually, I don't know that I, now that I think about it, I think it's the second law, yeah, okay, they always say the second one, that

0:26:06 Bryan: So the one that creationists use is a massive misrepresentation, and, uh, from my best understanding, it doesn't cleanly map on to any of the law, yeah, it's probably basically the second law, except they misunderstand it to such an extent that what they say it says bears no resemblance to what it actually says.

0:26:23 Thomas: Sounds right, yeah.

0:26:24 Bryan: Yeah. Yeah, so the laws of thermodynamics, you have just summing up first law, conservation of energy, second Yeah second law law, entropy. Third law, can't reach absolute zero. And I'm numbering them one, two, three, but there are actually four laws of thermodynamics numbered in a way that would satisfy a programmer. They're numbered zero, one, Two, and three.

0:26:34 Thomas: That's that, oh, okay. Gotcha.

0:26:51 Bryan: And law zero is just a Temperature is a thing.

0:26:50 Thomas: Zero, yeah? Yeah, that would always make me think that he thought of the zero one last and was like, oh, crap, that should have been the first one. Yeah.

0:26:59 Bryan: Yeah. That's basically what happened. Yeah, it came like a century or so later. Everybody was writing these third laws. I was like, you we kind of forgot something obvious. We should really define temperature first. We're using temperature all over the place, but we never bothered to define it. So they shoot one in and put like, oh, oh yeah, law zero.

0:27:05 Thomas: Oh, OK. Oh, I love it. Oh, what is the temperature? How do you define temperature? I guess I've never thought of that.

0:27:23 Bryan: So it depends how technical you want to be. A lot of these things, when you try to define things in physics, you have to get very specific about it. So temperature is a property of some system, which has itself the property that two systems in contact will over time equalize in temperature between the two of them. If they're equalized in temperature, we say they're in thermodynamic equilibrium. Equilibrium And temperature also has the property that if one thing A is in equilibrium with thing B and B is in equilibrium with things C, then C and A are also in equilibrium, which

0:27:26 Thomas: Mm hmm. Hmm.

0:28:06 Thomas: Could have told you that there's transitive property of whatever. Yeah.

0:28:07 Bryan: Well, It's basically saying that there's only one type of temperature, that the temperature of air is the same as the temperature of iron.

0:28:15 Thomas: Hmm. OK, gotcha. Interesting.

0:28:18 Bryan: And you don't get weird effects like you put three things in contact with each other and you have temperature exchange between only two of them, not the third. It's all the same thing. And if you measure the temperature one thing, it's equivalent, equivalent to that of another.

0:28:18 Thomas: Interesting, yeah.

0:28:34 Thomas: There's no like specific like 20 degrees Fahrenheit, but it's also 20 degrees oxygen Fahrenheit that was like a different temperature, that that's chang get on the line, try to create that hypothetical, how does that work?

0:28:40 Bryan: Yeah. You actually do get something like that with pressure. Pressure is related to temperature, but you multiply it by the number density for a gas, or it could have other properties like solids and liquids will have much lower pressure. Like solids don't really have any pressure, and liquids Will have much more limited pressure. So pressure is something like like that, where you can have equalities of pressure, but it's different between different materials.

0:29:06 Thomas: Hmm. Interesting. Hmm.

0:29:15 Bryan: Then there are other properties of temperature, like it has a lot of effects, like it'll accelerate or decelerate certain chemical reactions at different temperatures. And if you get down to the atomic or molecular level, you can describe temperature as essentially the random motion of all of the particles, um, so it's just the different chaotic motion as opposed to any sort of ordered motion, like if you take all sorts of particles in a box and then you move it uniformly at light speed into in one direction, yeah, that's motion, but it isn't temperature. But if you set each of them off in a different random direction direction, well, not just that they aren't colliding. You can have temperature without collisions. And in fact, with what we call an ideal gas, we're assuming there are no collisions.

0:29:52 Thomas: Is It because they're not colliding, hmm. Okay. Oh. Okay.

0:30:04 Bryan: So temperature is basically the typical difference in motion between various particles rather the overall motion of it. So you can think of it like you bus full of people on average, they're all going in one direction, but they're in the middle of a big brawl, a movie -style fight on the inside. And the more intense that fight is, the higher the temperature.

0:30:05 Thomas: Okay.

0:30:31 Thomas: Interesting. Gosh, that's weird try to even think of. So, with that in mind, how does temperature do what it does? You know, like, how do we feel the burn of something, you must cause other effects and, you you know, and other things. Yeah.

0:30:46 Bryan: Yeah. So burns and stuff are chemical reactions. A biologist might correct me on the details there. But typically speaking, a higher temperature will increase the rate of chemical reactions or enable ones completely. And what's going on there is that as the random motion of things increases, the rate of collisions increases. So temperature doesn't have to involve collisions, but it can. And like for a lot of things, when does, it will make them more frequent. So obviously, if people are moving around faster within this bus, they're going to hit each other more frequently and cause reactions with each other. So when you increase the temperature, you increase the rate of these. And there are also some things that will only happen if the temperature is high enough. Like if people are just moving leisurely around the bus, you won't expect any broken bones.

0:31:12 Thomas: Yeah, yeah.

0:31:45 Bryan: But if they're running full speed at each other, you'll get some broken bones, so that sort of reaction will occur. And then it's this at a microscopic level, which is essentially how temperature can give you burns. Yeah.

0:31:59 Thomas: Or I trigger nerve, you... It's just interesting to think in terms of that, like, it, you're just thinking intuitively, like, how hot burn does that, but then when you think like, okay, what's actually happening there? It's really interesting to try to look in that different kind of paradigm.

0:32:14 Bryan: That's the zero width law of thermodynamics, and before going on into the other three

0:32:18 Thomas: Well, that was all just the zero, oh, I thought we were kind of combining all of them. Geez, all right. Oh,

0:32:19 Bryan: Yeah, yeah, oh, no, yeah, for going onto the other three, I think it's, uh, to rewrite them in a phrasing known as Ginsburg Theorem, which is named after the poet Allen Ginsburg, apparently, but he wasn't the first to come up with this. It's one of these things, it gets named after someone who didn't come up With it. Essentially, it rewrites the laws of thermodynamics as law zero, you're in a game, law one, you can't win, law two, you Can't break even, and law three, you can't leave the game.

0:32:34 Thomas: Wow.

0:32:53 Thomas: Dark, right?

0:32:55 Bryan: And essentially that is what they say. Let's go over the remainder of these laws. So law one, you cannot win. I mentioned briefly that the first law is conservation of energy. When they're talking about this in thermodynamics terms for the first law. The way they typically phrase it is work done on a system equals the change in its internal energy. That is, if you use energy to do something to a system, that energy is going to be added to what's inside of it. So basically, the you can't win means you can't create more energy in a system than you put into it. Or in other words, what the reversalists are trying to do is impossible. They want to create more pressure energy in a system than they put into it, which the first law of thermodynamics says, no, you can't do that. Energy is conserved.

0:33:52 Thomas: Right.

0:33:52 Bryan: One, pretty simple. We've talked about conservation of energy. The is really just rephrasing it in terms of thermodynamic and the way people tend to talk about it. Law, you can't break even, is where it gets interesting. This is where we have to bring up the concept entropy. People who have been listening to all these episodes will probably remember late last year, we an episode on entropy and the human mind and the entropy of information. The way I describe entropy there is a measurement of what fraction of energy in a system can't be used to do any productive work. The way I like to describe it. It's commonly associated with disorder, which I don't like, as there are a lot of cases where the intuitive sense of disorder doesn't match with the strict physical sense, but you think about it as the energy that can't be used to do work, it does match up in most cases, so the entropy is the unusable energy in a system, but there's a little, a little bit of, you have to multiply by the right constants to get in the right units, but yeah, don't worry

0:34:34 Thomas: Isn't That always

0:35:10 Bryan: About that Yeah. Yeah. It doesn't have the same unit, strictly speaking, so what the second law of thermodynamics says is, uh, entropy of any closed system, which is basically there's nothing else it's interacting with that we aren't measuring, the entropy of any close system will only ever say the same in reversible processes, or increase in in irreversible processes, as time goes on.

0:35:10 Thomas: The case. Yeah, I don't Remember that part? Stay the same in irreversible, what does that mean exactly? Oh,

0:35:39 Bryan: So A reversible process is, as it says, something that can be perfectly reversed and set back to where it was. So to think of it this way, just imagine a perfect pendulum, in a gravity field. You lift it up to one side and set it swing. And it's a perfect pendulum. It doesn't lose anything to friction of the chord. There's no atmosphere slowing it down. So it's just going to rock back and forth forever. So you can say there's like the process of it getting from the top of its arc to the bottom, transferring potential energy into kinetic energy, and then back again as it keeps going on through its arc. And we call this a reversible process as it can go back to the starting point and be exactly as it was at that point.

0:36:30 Thomas: Okay. Oh, So entropy isn't changing there? Okay, got it. Yeah, so it's okay.

0:36:39 Bryan: Yeah, And then an irreversible process is one where entropy increases over time. So this would be like if there is friction in the chord of the pendulum, or it loses energy to the atmosphere. It may come back to a peak of its arc again, but it won't be as high up. It's going to lose a lot of energy tothe atmosphere around it. And you can't take that energy back and put it in as the time it gets back, the energy has been dissipated into so much random motion in the atmosphere that you can practically put it back. Now, you can add, yeah, Heat, heat, sound energy, all sorts of what we call dissipative energies, you, that energy is still there. Conservation of energy is still true. It's just changed from useful energy into non-useful energy or entropy, entropy, again, caveat, yeah, yeah, not the same units, um, that, that's fundamentally what's going on is the entropy increases as the useless energy increases.

And now one corollary to this, which connects it to the you can't break even statement, is that the formation of memory in our minds is by its nature an irreversible process, which means that everything we as humans experience is going to involve the increase in entropy. You, even though we could imagine like an ideal pendulum, us experiencing it, once we add ourselves to that system, the entropy is going necessarily to increase. So

0:36:41 Thomas: Hmm. Right.

0:37:16 Thomas: Or Is it like heat or something or anything

0:38:22 Bryan: Overall, yeah.

0:38:22 Thomas: We can't make a us, or a member, or our brain, or whatever, that somehow is just pendulums, and that it's all completely reversible, and may, and that makes sense, as much as I wish that were true, like the perfect renewable energy or something, like it makes sense that, like, well, you haven't really done anything, because it's reversible, there's no way that that, that can actually form, you, real computation, right?

0:38:44 Bryan: That us to the you can't break even, that anything we're involved with, the entropy is going to increase. The interesting thing is, if you go down into the mathematics of it, the parts I've skimmed over, you'll notice, wait, maybe there's a loophole here. One of the things I've been skimming over is that if you want to take the amount of entropy, translate that into how much unusable energy does that represent, you have to multiply it by the temperature. And that's one of the things you do in that equation. It's just constant times entropy times temperature equals unusable energie. So what if that temperature is exactly zero? Zero in that case, any increase in entropy, which could still happen, a could still allow entropy to increase, but if temperature is zero, we're not increasing the unusable energy. So what

0:39:00 Thomas: Love a good loophole.

0:39:39 Thomas: So what

0:39:39 Bryan: If in our say

0:39:40 Thomas: If we, if we turn up the AC really, really high, so we're just frigid in here, then do we get a free lunch?

0:39:40 Bryan: Yeah yeah Exactly, so this is our loophole, we're saying, oh, but these are the laws of thermodynamics, what if we have no thermo, we set thermo equal to zero, can we leave yeah Yeah, yeah, yeah, that's basically thinking, OK, can we leave the game? Well, that's where the third law comes in. It says, no, you can't leave the game.

0:39:58 Thomas: Yeah. And we just get the dynamics.

0:40:10 Bryan: Being

0:40:10 Thomas: The game being what? The restrictions of, okay, yeah.

0:40:12 Bryan: Thermodynamics. Yeah, the restrictions of it and the other effects we've seen that essentially law two being the big one, that entropy will always increase. We get away from that. So what law three actually says, if you read it in a physics textbook, is that as the temperature of a system approaches absolute zero, the entropy will approach a fixed value, usually close to zero with some exceptions, but always a fixed volume. Now, when I say that, I don't expect that to mean anything to most people. You have to do a bit of math to connect it to what actually implies. And once you do the math, you can say what this means is that you can never reach absolute zero for any system in a finite number of steps. You can set up an infinite series of operations that will converge to absolute zero after an infinite amount of time. But there's no way in.

0:41:14 Thomas: But who has time for that?

0:41:15 Bryan: Yeah, yeah, nobody has time for that. But in the real universe, there's no way to actually get to absolute zero, and this means that, you know, there's maybe that loophole that if we plug a zero into these equations, it'll all work perfectly without losing entropy. But no, the third law is you can't leave the game, you can't get get out of the implications of this by decreasing temperature to zero. Now, you can reduce the impacts. If you have a computer running at a low temperature, the limit for how much entropy it's going to add will decrease. The impact of it can decrease. You can get more efficient as temperature decreases. Lot of other things you can make more efficient if you can reach a lower minimum temperature.

If you cannot reach zero, you'll never be perfectly efficient, and you'll always lose something to entropy at one of these points. So that's it, the three laws of thermodynamics. And what I like about this story is in a lot of ways, it kind of illustrates this society trying to grapple with These laws, original discovery of the pressure increasing, is the Law Two discovery that everything they do is causing an increase in the pressure outside of them. And then the reversalists trying to create more pressure in a container are running up against Law 1, they can't get more energy out than they put in. Then Law 3 is a bit more metaphorical, but it's kind of the feeling settling the narrator that there really is no escape from this. This

0:41:24 Thomas: Yeah, yeah, yeah.

0:42:55 Thomas: I think he represents that to Ted Chiang does, maybe, because which one was that, the absolute zero one?

0:43:00 Bryan: Yeah.

0:43:01 Thomas: I think that maybe is represented in the talks of adjusting like, to the temperature, differential in a way like, oh, if we could somehow maybe I'm wrong. But I feel like there's a little bit of just talk there of like, can we make it such that, the you workings of our brains don't as much pressure And can we, something you that way?

0:43:21 Thomas: And then it still doesn't get us out of it.

0:43:10 Bryan: Yeah, Yeah, it doesn't get us out of it. And they of ways like, can we reduce how much we use? Like, what if we just take our heads off and only become thinking minds right next to the reservoir from the center of the planet? We can extend our lives that way. And this is, in a sense, thinking like, what's the end state? Can we get down to zero use? And you can approach it, you can reduce it, you but can never entirely get down to zero increase in entropy, which is essentially what the third law says, is that you slow down the game, you you can mitigate your losses, but you can never stop them. Know, there's certainly benefit to slowing down your losses. Like just going to the real world here, we increase by creating waste. And if we were to, things you around so that we don't create waste as that will have benefits over time. Won't prevent us from eventually running out of raw materials or space to put our waste, but we'll be able to last longer.

0:43:33 Thomas: Right. Yeah.

0:44:29 Thomas: Yeah. I always wonder what the efficiency possibilities are there. Yeah, we can't get to absolute zero, but you can get pretty close, and Then like, can you stretch stuff out enough, you know, just based on math that things get functionally infinite? You know, I like, often in mathematics that can kind of happen where it's like, yeah, okay, you know, you can't really stretch this to infinity, but like, if you get that, you know, denominator, uh, enough or something, then you're you're close to zero. And I wonder how much of that is true when it comes to things like, I don't know, renewables and just, I the guess entropy death of everything. Mm.

0:44:36 Bryan: Yeah.

0:45:05 Bryan: That's actually interesting you say that, because brings me to the final point. It's- it's, what is the end here? So, Let's imagine they do everything they can to reduce the- they one robot person as a survivor to be the final brain in a jar that will be the only use of pressure. So as it goes on, they're allowed to continue thinking about whatever as the pressure slowly equalizes. And eventually the pressure outside is going to be very close to the pressure in the reservoir, and the rate of exchange is going to be proportional to the difference.

So the- at which this robot can think will slow down as the air is slowing down, for the physical where the pressure has to blow gold leaves, there will be some point at which the air isn't blowing fast enough to lift the leaves at all. So there will be a shutdown point for them due to the physical setup.

Though we could imagine, what if you had some theoretical setup where as long as there's any differential, there will be thought going on, even if it gets slowed down? Maybe they figure something out to transfer their minds into. Could they last indefinitely thinking? Well, this is the point where it gets even more interesting- is the laws of thermodynamics, or in particular, the second law, is really, when you get down to it, strictly speaking, more of a suggestion than a law. It's

0:45:11 Thomas: -hmm. Oh. Yeah.

0:46:45 Bryan: It arises out of statistical likelihood. We talked about this a bit before. Imagine you have a table with 100 coins on it, all of them initially heads, and you flip coins at random. Now, when they're all initially heads the only thing that can happen is that some will turn to tails or stay the same. So while you're doing this, the entropy increases. It goes from all uniform to more of the mixed state, which corresponds to an increase in entropy. Now, when more of them are tails, there's a chance that the entropy will decrease. Like if you have 10 tails and 90 heads, then when you go flipping them, There's maybe % chance it'll decrease. Once you get up to it's all completely mixed, 50 % heads, 50%, tails, pretty much any that you flip will decrease the entropy. Now, in the universe, we have more than just 100 particles, a little bit more.

0:46:50 Thomas: Yeah. Mm hmm.

0:47:53 Thomas: Yeah, I think we're like two to three

0:47:55 Bryan: Yeah, yeah. A hundred. So the odds of the right ones being flipped to decrease the entropy are very low. But imagine we're in the end stage of the universe. Entropy has increased as much as possible. So we're You're in the state where our table is half heads, half tails. The only way entropy can go is down.

0:47:55 Thomas: Hundred. Yeah.

0:48:20 Thomas: Because the odds of it just flipping to constantly be exactly 50 50 is actually is kind of low.

0:48:24 Bryan: Yeah. Yeah, you if you flip one at a time, yeah each of those, you've got a 50 % chance it'll stay the same but, you Know, enough flips. It's definitely going down. Now, once it's down, it's more likely to go up than down but it could go down again. Again, there's nothing preventing it and it could keep going down. So what could theoretically happen is that, you know, if the universe is infinitely large and if it lasts an infinite amount of time, maybe there's going to be some period of the universe where just by random chance, the entropy keeps decreasing and decreasing, just pure luck. And eventually the entropy decreases enough that it's, well, back where our universe started. Then maybe the luck of it going down will run out, but at that point, the entropy is low again.

0:48:40 Thomas: Hmm.

0:49:19 Thomas: We get a free bonus universe. A?

0:49:21 Bryan: Yeah, essentially. Universe equalizes out to a heat death, but then at some point, it just runs in reverse. Just happen to align the right way to organize themselves into a new universe, and we get to go again. It won't be us. All of the information of our lives will be lost, but new lives could exist in that universe. Weird about infinity is not only can we say this could happen, in enough time it definitely will will happen, and in enough time, it definitely will happen an infinite number of times. Infinity's weird that way. Although is guaranteed to go out and run out of usable energy at some point, if universe lasts an infinitely time, which it might well, well, there will be others around.

0:50:14 Thomas: There's no way to like freeze us so we could survive that, like, Well, in the state of right?

0:50:19 Bryan: The absolute zero problem. We can't leave the game. Yeah.

0:50:23 Thomas: In the state, so like, in this maximum entropy is the end state, right? In Maximum entropy, what does that look like? Like, does that just mean every single kind of molecule is like falling apart to where it's just a, just kind of all the same sort of, not nothing, but the same sort of uniform, you know, thing? Like, what does our universe look like in that state in a good 11 gazillion years, right?

0:50:28 Bryan: Yeah.

0:50:50 Bryan: Well, it's going to be mostly empty. Just the expansion of the universe is going to see to that. And even the things that we do think of normally as end states, like black holes, our understanding of black holes says that they will evaporate through what's called Hawking radiation, which is like a weird quantum mechanics loophole that allows black holes to spew out particles. Usually this doesn't keep up with the rate at which things fall into them, but if the universe expands so much that the density in the background keeps decreasing, then at some point the Hawking variation of black holes will be greater than Then the rate of things falling in, and the black holes will slowly evaporate.

The universe would be left with a lot of individual particles going around it randomly. We think with our, that the universe will keep expanding indefinitely and the expansion will accelerate, which, it hard to see how we would ever have things come together into starting another universe. Even if we allow for random motion, accelerating expansion does make that more difficult to see. That's just our universe, and we do have the open question of where did our universe come from? Universe just one in a chain of, for some reason, luckily, entropy got really, really low, and then interesting things started to happen? Happen? Or does our universe come out of some sort of other thing which spawns universes?

0:51:31 Thomas: Yeah.

0:52:04 Thomas: Either Way, we're fucked, I think.

0:52:30 Bryan: Yeah, there isn't an escape for us. Again, well, infinity is weird. There's going to be infinitely more universes. And a lot of them are going to be pretty similar to ours just due to the random chance, so essentially we get, uh, the multiverse for free, we get the of this universe which is just like ours, except everyone is evil and has goatees. Yeah.

0:52:51 Thomas: This was all true before we discovered the like increase an expansion of our universe, right? Don't these laws predate that? So is that like an extra thing or is that, cause I'm wondering if, if our universe weren't expanding, which I feel like it could have been not, right. I mean, we could have found that actually it wasn't expanding like that. That wouldn't break science or anything. Right. Wasn't that a pretty contingent fact?

0:52:58 Bryan: Yeah. They do, yeah.

0:53:10 Bryan: Yeah. Definitely. It was certainly plausible that, you know, the universe maybe was expanding or would stop expanding and Collapse, that, that Was considered to be distinctly possible, uh,

0:53:19 Thomas: Yeah. So Then how does the entropy thing interact with that? Like it, like it's two different things, right? Like, the expanding universe isn't necessarily the same, uh, as like this entropy heat death thing, right? Yeah.

0:53:32 Bryan: Yeah, they together, but heat death is really specifically referring to entropy. Even if the universe was a fixed size, you could still have what they call heat death. And heat death means the death of heat, where heat specifically refers to the transfer of temperature around the universe. So it wouldn't thin out to nothing, but it would be basically uniform. It's the difference between being your average room with all sorts of interesting objects, the chair you're sitting on, you, to being a sludge of random particles everywhere. So it still could reach that maximal entropy state, even if the universe is fixed inside.

0:53:38 Thomas: Yeah. Yeah. Everything Gets Uniform Mostly It feel, okay, let's pretend we're no expanding universe, it's a fixed size and we're sitting here in it, we're like those robots, kinda, doesn't Just feel like, well, there's... there's got to be some way that we, like we can move around, we can do stuff, can't we? We stopped that from happening, but is it just like inevitably entropy increases, increases until where just can't do that.

0:54:24 Bryan: Yeah.

0:54:36 Bryan: Basically the only way out of it is extreme luck, and it just comes down to going through the maths carefully on where entropy comes from, and you can demonstrate that it is essentially this coin flipping problem, except we're one of the coins. Now, we could try to flip another of the coins in a different orientation, but since we're of the coin ourselves, you know, Newton's third law, every action has an equal and opposite reaction, that we're going to cause the opposite effect on ourselves. So, as we're always part of this, anything we do to decrease the entropy in one location, which, yeah, we can do, we can locally decrease it, we'll increase it somewhere else. And this is essentially kind of the moral of this story, that trapped in this game, and as you're part of it, anything, anything you do to try to fix it will just change where the entropy is increasing. It won't stop it.

0:55:35 Thomas: Weird. So what does that look like in practical terms? Like eventually we just run out of energy that we can use for stuff and

0:55:41 Bryan: Basically, like, stars will eventually burn out. Various interesting things will happen. New stars will form. There will be pockets of the universe where it's still dense enough to form stars. And you have the right types of atoms which can generate energy by fusing.

Then those stars will be less common, there won't be as many pockets of density, but there still will be stars, they'll burn through and then eventually explode or whatever, expel some of the remaining energy, the pockets collapse, but they'll be even rarer still, and just, you, slowly over time, stars happening and there being planets will become less and less common throughout the universe, until eventually that it's basically a zero chance of it happening anywhere.

Everything is spread out too far, that the gravity of a gas cloud can't overcome the expansion of the universe. And so all that's left is a thin gas of particles, something weird happens with the overall nature of the Universe we don't know about, out, like how our universe was spawned to allow it to happen again, which, you know, is probably pretty likely that it will, we don't know how, but given That The, yeah, we won't be here, um, even if we can survive the things that are currently facing our society, we will eventually have to grapple with the problem that our sun has a finite lifetime. Now

0:56:58 Thomas: We won't be there.

0:57:12 Thomas: Yeah.

0:57:12 Bryan: It's billions of years, that's, it's a long time, far longer than any human lifetime or all of human civilization, but it does have a timer on it. Now, we could go to other stars, and stars will extend that if we figure out space travel, but eventually no new stars will be created. So even if humanity does everything perfect, eventually the universe is going to run out of stars, it's going to ran out of fusible matter, and we just won't be able to do anything to create new energy.

0:57:43 Thomas: Crazy. Well, I'm we'll, we're, we've, we, we we'll figure that out. We'll cross that bridge when right. Right. Well, this has been so fascinating. Again, I highly recommend not only this short story, but everything Ted Chiang. He's so interesting to me. He also wrote the book that became the movie Arrival is another one of his short stories. It's called The Story of Our Lives, I think. It has a different name than Arrival, obviously, but highly recommend. And thanks so much, Dr. Brian Gillis, for taking us through that. And I'll see you at the heat death of the end of the universe. Is there anything you want to plug until then?

0:57:51 Bryan: Yeah, Yeah. Well, let's give Ted Chiang a plug. His name is C -H -I -A -N -G you Your platform, he's probably there, and a lot are also available for free, like Exhalation has been posted in full online in text, and they're even in podcasts made of reading it. I'll put links to it in the show notes for anyone who wants to find it and listen to a reading of it.

0:58:19 Thomas: There you go. I already did.

0:58:34 Thomas: Oh, wow. Love it. All right. Thanks so much for listening, everyone. And we'll see next time.

0:58:43 Bryan: Thanks for having me on, Thomas.

0:59:01 Bryan: If we have no thermo, we set thermo equal to zero, can we leave

0:59:03 Thomas: Yeah. And we just get the dynamics.

0:59:05 Bryan: Yeah, yeah. Yeah.