#808 - Dr David Kipping - Black Holes, Alien Civilisations & How The World Ends

26:00So if you give me the starting positions of those two particles and you give me the momenta, which they're moving, then again, we should be able to calculate for a billion years into the future to exact precision where there will be. But this all kind of breaks down when we get to three bodies. So when you have three, same situation, just three particles, you know, they're initial positions, you know, they're initial trajectories. Now you can predict where there will be, but if you very, very slightly deviate one of those particles. So you just say, I'm going to shift one of those particles a millimeter over to the left and redo that calculation.

26:36You will get a wildly different answer for the final outcome. So this is called the butterfly effect. So if you know, butterfly flaps its wings and you think what differences that make, but if you propagate it over a long enough time, it can have enormous implications. And you know, people have, you know, playfully say it could cause like a hurricane, right? The flaps of butterfly. That's maybe a little bit exaggerated. But in this case, certainly a very slight nudge to one of these particles will give a wildly different answer. So whenever you have a system like this, we call it a chaotic system, because it means we cannot make predictions that are reliable about their final position in a million years, a billion years from now, because we can never know the position of a planet to absolute precision.

27:16There's always going to be some slight uncertainty. And if you nudge it within that uncertainty, you get a very different answer. So it's not the same as being random, because there's not randomness. It's still fully determined, but so chaotic and complex that it's unpredictable. Is that a way to say it? Yeah, I think unpredictability is the key word. It's that you can't forecast with any meaningful accurate prediction where it will be. You can actually make distribution so you can say, I'm going to run this simulation a thousand a million times over and over again and just slightly nudge it around and see what the spread of results are.

27:53And then that can kind of help you to like place your bets as to where you think is most likely to land, like how you go into the casino and gambling where you think the ball will land on the roulette table. So you can kind of make that kind of statistical analysis, but you certainly can't make a good prediction. So even for the solar system, this is true. So for the solar system, it's been shown that if you go forward about a billion years into the future, mercury is not necessarily stable. So in about 1 % of simulations, I think it is. and this is where it done by Constantine Batigan during his PhD, he showed that about 1 % of the time the solar system will become unstable.

28:32So in 1 billion years, that's before the sun actually will long engulf the earth. And what tends to happen is I think mercury gets ejected from the solar system altogether and earth and Venus swap positions. So earth becomes the Venus and Venus gets a chance to cool down and could potentially become habitable, I suppose, if it was far and afraid from the star. So it's pretty wild that even the solar system, which we think of as incredibly ordered and structured and long lived, as not just a three -body system, but a many -body system also has instability. So the real question is, for any multi -body system, not whether it's chaotic or not, they're all chaotic.

29:11The question is, how long is that chaos timescale start to creep in? And so for the solosystem, the chaos timescale, it's called the lupin of number technically, it's around about five billion years or so, whereas for some solosystems that we look at, the chaos timescale is very, very short of 100 million years. And so for those who are really looking at them thinking, that thing might not even be around here much longer because it just seems like it's bats on a knife edge of instability. That's so cool. Chaos time scale being how long will the current system remain similar in terms of what we would expect to see?

29:50I think it's better to think of it as when do your predictions diverge? So, you know, almost like in a multiverse scenario of living different lives, if you, you know, like in the film sliding doors, when you get on the train or don't get on the door, over what time scale do the outcomes diverge? Meaningfully. Because presumably there's a 0 .00, not 1 % chance that Mercury gets ejected tomorrow. Correct. Yeah, there's a definition of exactly what that means of how quantitatively large it has to be. But typically it's a border of sort of an exponent number. So that's like a power about 2 .5 in terms of like the semi -deer axes, the orbital periods, things like that.

30:24So if they change by a factor of two or three, then that's definitely a very major change to the order of the system. How is it the case that there's so many bodies in the solar system and yet were relatively stable, at least maybe for the next half billion to a billion years? Why is there seems to be so much going on? How is it that orbits get settled into kind of reliably? Why is there not more play in the system? It is kind of a miracle, right? It's a miracle of stability that we should be thankful for, because if it wasn't so, then we wouldn't be here, but on the other hand, perhaps that's the answer right there, that if it wasn't so, we wouldn't be here to talk about it.

31:05And it's not a guaranteed situation. So when we look at other exoplanet systems, which we have been cataloging now over the last 20 years, it's actually quite rare that we see a solar system that looks like ours. There's something not necessarily completely unique, but rare about the structure and architecture about a solar system. For example, we often see plants in highly elliptical orbits going around their star, which if an solar system, if you had a plant like that, if Jupiter entered a highly elliptical orbit for whatever reason, it would completely destabilize the rest of the plants. We also have lots of hot Jupiter's.

31:39These are Jupiter -sized plants which are orbiting very, very close to the star. And again, in order to get Jupiter, which passed a form far out in the star system, to migrate inwards, it's like a bulldozer coming through the planetary system. It just knocks everything else out. But it's possible that the solar system had instabilities. It's thought that at one point in the past, there may have been another planet similar to Uranus and Neptune that we lost. So there could have been what's called the fifth gas giant in the solar system. And the reason why we think this is true is that when you do these simulations and you put the eight plants in and you let them all interact with each other and you speed up over time, you very often find that Uranus or Neptune get ejected.

32:21the solar system in like half of the simulations. So therefore it seems odd, you know, how, if Uranus and Neptune are so unstable, why are they so stable when we look at them today? So the explanation for this in David and S. Vornier, one of my colleagues at the Southwest Research Institute suggested this, he said, look, if you put in an extra planet and the back end of that solar system, it's the one that often gets ejected and it sacrifices itself to save Neptune and Uranus, and then that all make, and everything makes sense if you do that. So even though we don't have direct evidence for this fifth giant planet, it kind of neatly explains why the outer solar system seems coherent and stable because it wasn't always coherent and stable and it's only got that way as a result of basically chucking out the unstable stuff.

33:07So we don't just have a rare earth hypothesis, we have a rare solar system hypothesis as well. Yeah, I think about this a lot. This is one of those thoughts that really bother me as nexoplanet scientists is understanding how special and unique we I'd say it's like the driving question I have as a scientist is, is our home? Is there something special about not just the Earth, but maybe the Earth Moon system, the solar system, even our Sun, even our part of the galaxy, maybe even our galaxy itself, like where, which aspects of this are special and which aren't? For example, the Sun is not a typical star, only about 10 % of stars in the universe look like the Sun.

33:43And amongst those, our Sun is unusually quiet. Most stars have lots of flaring and activity, lots of star spots, our sun is is curiously very very stable as well in terms of some luminosity output. So that's also kind of odd. You look at the solar system, we have a gas giant. As far as we can tell, just having one gas giant is kind of unusual. Certainly less than 20 % of exoplanet systems have that, possibly as low as 10%. So just having a Jupiter around your star is weird. And Jupiter is thought to be potentially a good thing because it could Hoover up or the Asteroids, for instance, that's been suggested.

34:19Maybe that protects the earth from getting bombarded something in one of your videos. Where was it 2000 and When did Jupiter take one for the team recently? the Schumacher Levy Yeah, that hit it. Yeah. Yeah, that was a huge impact that that one. No, it was a kid So yeah, I wasn't when I was in professional astronomy I think this is when I was like 13 or 14 I think that was happening And I remember seeing it in the news and seeing the images But that was a situation that obviously happens very often. If it happened in a human lifetime, it's happening probably every few decades or so to a plant like that.

34:54So that's not surprising. And if that had hit the earth, it would have definitely extinguished life on earth. No doubt about it. It was a massive, massive impact. So having, having Jupiter take that for a team was one that we were pretty grateful for. Have we got any idea about the odds of life and intelligence? That's something that is definitely right at my street. I'll be thinking about my whole career, I'd say. You know, there's something to say, there are two types of astronomers, the ones who want to understand how the universe works. They want to understand the mechanisms, what was the big bang, how does space -time work.

35:29And there are astronomers who just want to have this itch, are we alone? And it just drives you and you can't help thinking about it. And I've probably fallen to that latter category. I find both questions very interesting, but that latter one really bothers me. Calculating on odds is very difficult because there's only us that we know of. So you have 100 billion stars potentially, and so a lot of people would say, therefore, the probability of life somewhere in the galaxy is very high. Because if the probability is say 0 .1%, then that would mean there was millions and millions of civilizations out there in the galaxy.

36:05Fine, but we don't know that the probability is 0 .1%. So there's 10 to 11, 100 billion stars, let's say 100 billion potentially Earth -like planets out there. But if the probability of life starting on each one of those Earth -like planets is less than 100 billion, then it's just us. That's it. And that's just life. I mean, then you could add on, well, what about more to sell your life? What about you, Carriots? What about photosynthesis? What about getting all the way up to intelligence and technology? because intelligence in technology not the same thing. You have intelligence species on earth which do not have technology, such as, you know, crows or humpback whales and dolphins and things.

36:44So just being intelligent isn't enough either. We have no idea what the outcome of all those steps would be. But what we do know is that life started pretty quickly on the earth, and that's interesting. So we can look at the time scan, we can say it happened within about the first, maybe 200, 300 million years as evidence for life on Earth, since when the oceans formed, whereas intelligent life took a lot longer, took intelligent life, you know, four, four and a half billion years, spending one year's, you make the start date. That's a long time, and the Earth will not be habitable that much longer.

37:19I just think this is kind of an amazing fact. The Earth will probably be uninhabitable to complex life in less than a billion years. About 900 million years. So if it had taken only a little bit more, We would have been just about getting to the stage of intelligence just about when we would be uninhabitable. Yeah. Yeah. There's a really interesting idea called the Hard Locks idea that Brandon Carter wrote about. And his idea was it's kind of odd that we have these major evolutionary transitions, such as the development of a conbe genesis, which is sex, the development of eukaryocells, photosynthesis, all these major evolutionary develops.

37:58They seem to be kind of uniformly spaced in time from the start date of Earth to the end date of Earth They seem to be kind of uniformly spaced and he said look that's actually similar to trying to pick a lock a Very hard lock so imagine you had a sequence of doors in front of you and The lock on average would take let's say a hundred hours to pick but I only give you 30 minutes to pick all six and you've got to get through these six locks to get to the end now the vast majority of people of course will not get through the six locks and they'll look and we just never hear from them. They never become intelligent civilization in this picture.

38:34But very, very rarely someone will be fortunate enough, just very lucky that they'll get through those six locks despite the fact the odds are against them. And when you look at the distribution of how long it took them to get through those locks, they end up being uniformly spread in time, even if the locks are grossly different in difficulty. So the first lock could take maybe an hour to break. The next one could be a thousand hours. The next one could be ten hours. And if it is long as, they could be completely different numbers. As long as they're all hard, the final distribution is always uniform, which is what we see.

39:09So he suggested this is consistent with each of these steps being incredibly unlikely events. And that would naturally explain why they seem to be almost coincidentally evenly spread in time in the evolutionary record. which is obviously bad news if it's a touch and live if that's true then yeah people are the hurdles to get over are all really really high yeah so I I'm receptive to that argument the only real thing I feel confident saying anything about on this I've done a paper about this a few years ago where I said well let's just intelligent life is hard to deal with but let's look at the early life situation and despite the fact life did start early when when we did this full -basine analysis of the timing and the chronology of Earth's history, it is a good sign for life -starting again if we kind of rerun the clock, if we could go in a time machine and we did that and what we did for the chaos theory.

40:07We kind of push things around a little bit, we just notice things around and we rerun the tape and we see how often would life start again. And the outcome was that about nine out of every ten simulations we would expect life to start again, given that situation. So that's just purely looking at the chronology and how fast life started. But it's not a guaranteed, it's not a guaranteed outcome. So it is possible that you could have plants that do not form life as well. Whereas when it comes to intelligence, we try to do the same thing for intelligence. It actually slightly disfavored intelligence.

40:36It said that, you know, when you look at the numbers, it looks kind of unlikely that intelligence would happen again. But it was a very marginal result. And so we just really want that's telling us we need more data. Whenever you come to a point where your statistical significance is kind of weak. As a scientist, that's a point to reflect that we need better data and certainly for intergent life and for life as well. We need more data. And my analysis was only restricted to running the Earth's tape backwards. I mean, who knows if Earth is common either? Like, the Earth might be special out there as well.

41:08What are the planetary conditions required for life as far as we know it? For life as As we know, the basic condition is liquid water. So every single living organism on this planet has to have a living water in order to survive. There are some animals and some creatures which can go without water for extended periods of time, but they can't go forever without liquid water. So that seems to be a basic requirement. You also need an energy source or a life metabolizes. So there has to be some source of energy for most life on Earth that essentially comes from the sun. Obviously, we get our food from eating animals and plants, but all of that essentially still derives from the sun if you go far enough back down the food chain.

41:52And then there's some things which like chemitroves, which get the energy from chemical gradients or from deep down on, you know, it needs the bottom of the ocean. There is some volcanic vents that could be a source of energy. So you have to have an energy source, you have to have water. And I think a lot of us think that you need some kind of information storage system as well. So for us that's DNA, some life uses RNA, whether there's other versions of that on other plants is an open question. As in, it's very interesting to explore. RNA seems to be a popular idea that it could be almost a common precursor for life out there that we might find.

42:29It's very difficult to form RNA spontaneously. So it doesn't seem like it's easy to make RNA, but somehow it must have got started. and once you get it, it's autocatalytic, so it can make more of itself, it does reproduce. But getting that first one is kind of the chicken and egg problem with life, quite literally. And then you probably also want to have some kind of cell structure, something to bind the organism together. It can't just be diffuse and just dilute across the entire ocean. It probably needs some physical structure, so that could be, for instance, like an oil droplet, can actually form almost a natural vessel without having to have an organism already around.

43:09You could have the oil do that job for you. So I've been suggested that in clays, they can form these little bubbles as well. If you have wet clay and cycling through it, you can form these bubbles and those clay bubbles could also be potentially little pockets that form like protocells as well. So there's lots of interesting ideas about getting the precursors to life going. But of course, that's just life on earth. It is possible that life elsewhere does not require liquid water. But I think there are very good arguments as to why it probably would. You want some kind of solvent and there are alternatives that you could imagine, such as alcohols, for instance.

43:48But in general, it's difficult to argue that water is both extremely common in the universe. It's one of the most abundant things out there. We see it in many, many planetary atmospheres that we've been studying over a couple of decades. So we know this stuff is all over the place. It's just hydrogen oxygen to the most obvious and common things in the universe, and it has so many advantages for life. So if you want to have liquid water as your basic requirement, then that all comes down to the surface temperature or the surface temperature of the object. You want to have it in that temperature range where it's not too cold, so it's not freezing to ice and not too hot, there's to steam.

44:24Why do you need the lubricant? The solvent? Solvent. Yeah, so you need the solvent to basically carry nutrients around the organism. If you have a completely solid object, it's difficult to imagine how it would transfer energy from different organelles and different components of the cell. So a solvent is just useful for for keeping, I mean, I'm not a biologist, but my understanding is just, is just to keep, keep a way of moving stuff around inside the cell. What else about the planet, stuff like the magnetosphere and plate tectonics and a big moon and stuff like that? What else is sort of rare about where we are?

45:05I mean, possibly the part of the galaxy could be rare as well. People suggested that where we live in the galaxy may be itself special. We live in a spiral arm and we live sort of like halfway to two thirds of the way out from the galaxy to its edge. Yeah, so the suburban district and we certainly think that if you were too close to the Galactic Center, that would be bad. As you get closer and closer towards the Galactic Core, the density of stars increases. There's a more and more stars, which means the spacing between stars decreases. Now that's problematic because you can have exposure to supernovae and gamma ray bursts, which can be essentially life extinguishing events.

45:46So if you get too close, that's a problem. We also did some work in my team with Moyamac Tier, where we showed that actually the instability we talked about earlier, the three -body problem type effect also gets worse as you get closer in, because stars themselves often not collide with each other but come very close to each And when that happens, the gravity of a nearby star can actually rip off and destabilize the planets around you or that you're trying to form. So this is bad and we think that, you know, certainly once you get within that inner core, you actually lose the majority of your planets this way.

46:19This is why you always get a little bit bothered. Sometimes you hear astronomers say, this is a pet heave I have with my colleagues that locally we know this is true nearby to the star that about, let's say 10 % of sunlight stars. have planets of similar kind of size to the earth. Not necessarily how it's well planets, but similar size to the earth. Therefore, there are a hundred billion stars. Therefore, there's a billion of those, 10 billion of those in the entire galaxy. Now, the problem with that is that we just don't know that we can extrapolate what happens locally in our neck of the woods to the entire galaxy.

46:55And especially to that galactic core, it seems very unlikely that in a region, you know, unlike Star Wars and Star Wars, that inner regions where like all the activities going, everyone wants to live in Coruscant, which is like right in the center of the galaxy. In the real world, you do not want to live in the center of the galaxy. That's actually a hellhole place to be living. So I don't think we can generalize these numbers elsewhere. And so when you look out to the outer -necked the suburbs of where we live, there are some reasons why it seems useful. We're finer for way for more that behavior, but we're in a region that's dense enough to be forming stars and dead cells to be forming planets, the metalistic radiance good.

47:31We also happen to move around the galaxy, orbit around the galaxy, is comparable to the speed at which the galactic arms themselves rotate round. And so, we're not crossing streams and other lanes of traffic. Right. Exactly. So we don't get these, these, the spiral arms are basically compression waves of gas that are moving through the galaxy. And those compression waves, as they push through, they lead to a star formation increases. So you have this compression, we've suddenly get more and more stars being born and that's generally hazardous to have lots of stars being born because that means you're going to have some stars which are going to go supernovae.

48:09It's not common, you know, one in a thousand stars will go supernovae but if you have a star forming surge, a few of them will and that's going to be bad if you live in that neck of the neighborhood. So it's like having a swarm of, I don't know, like migrants or something swarming through your neighborhood and some of them just explode randomly as they come through or something. You don't really want that. You'd rather be in a place where there's no visitors and it's a fairly stable place and fire and that seems to be kind of the neck of the woods that we live in. So in that sense it may be fortuitous that we live where we are.

48:43But this is an open question. I don't think we really establish this but we have some ideas as to why it might be so. But ultimately this is something we hope to test. If we can detect planets right down the center of the galaxy that would disprove what I'm saying and prove that actually planets can form in these bizarre places which would be again interesting to discover or maybe we'll even discover that there's Earth -like planets in that region and life in that region which would again append a lot of what I'm saying. So it's a testable theory but it is the only idea we've got right now pride having a data that there's it does seem like there's some advantages to being where we are in the galaxy.

49:19Rare Earth, rest solar system, rest suburb. It's so interesting to think about that number of, this is how many billion stars there are and this is how many planets we think are on average around each star, therefore if you run the numbers forward. But what it doesn't account for is that not all star localities are created equal and presumably as you get closer toward the center of the galaxy, that accounts for a very large number of the number of stars, but at a much lower appropriate environment within which those planets inhabit isn't sufficiently stable and long lasting to actually allow life.

49:57That's so cool. One of the strange things, not just location, but star type, is the most common type of star in the universe is a red dwarf. So 75 % of all stars are red dwarfs. And immediately you might think, well, how can we live around one if they're so common? But it gets even worse than that because as far as we can tell they seem to have more earth -sized planets around them than sun like stars do. And yet more, we know that they live for far, far longer. So the sun, as we talked about earlier, will eventually burn out and die. It will probably take another five billion years before it turns into a giant, but even within a billion years from now, it will become hot enough that it will make the earth uninhabitable.

50:37So this is climate change forced from the sun over a billion year times ago. That was just basically, I mean, there's no way for us to adapt to that and we will die. However, these red dwarfs, it's like everything happens in slow motion for a red dwarf. So their lives, they're extended to trillions of years because they're so small, it takes them a lot longer, they're much less efficient at burning that nuclear fuel in their center. And so that means that if you lived around a red dwarf, you could have a civilization which lasts far, far, far longer than we ever will. And so all of this kind of is intriguing.

51:11You know, you have, there's more of them, they have more earths, and they last a far longer. So they seem to have everything going for them. And yet we don't live around one. And that has also kind of bothered me in the past. And I called this the red sky paradox. Like why don't we have a red star in our sky, rather yellow star in our sky? And one possible resolution is that there is something wrong with red dwarfs that we don't yet understand. maybe the radiation they spew out is just hazardous to forming life in the first place. They have these very prolonged, I say, everything is slow motion, that includes their adolescence.

51:47So the sun went through, its adolescence pretty quick in order of like 10 million years, it kind of settled down, it chilled out, it stopped spewing flares out all the time. What happens to your adolescence? It's just a very active start. It's very unstable, it's very volatile, It's luminosity is changing dramatically. It's spewing at high -end -year radiation. It is not a nice place to be living during that time For red dwarfs that that adolescents extends for a billion years in some cases So the problem with that is that you actually eradicate the planets of their water So let's say the earth happened to be a water -rich world born around a red dwarf But then it's being bombarded with this high -end -year radiation We can actually remove the atmosphere completely off the planet.

52:30They're so powerful these events. When you remove the atmosphere, the water then just escapes. It boils off. It forms maybe clouds at a high altitude, but then the ultraviolet radiation, which these stars also produce, splits water up into hydrogen oxygen. So it's like, fishion of the molecule into hydrogen oxygen. And the hydrogen will escape into deep space. So an Earth -like planet does not have enough gravity to hold on to hydrogen. If you let out hydrogen in the air into a balloon or something, minus the weight of the film itself of the balloon, the hydrogen will just float off into deep space and not come back.

53:05The earth does not have no gravity to hold onto it. So once you lose your hydrogen, you now just got oxygen by itself. You can't make water with just oxygen. And so the planet loses all of its water this way. This is thought to have happened to Venus actually in its past. And so this is, which is a very dry planet and we can see that. So this is potentially an explanation is why despite the fact red dwarfs are everywhere, they may not be as hospitable as we hope. But perhaps civilizations go there eventually, they might be like the retirement homes, like the Florida of the universe. Because I think a civilization like this would recognize that there's something here for our future.

53:43Even though there's no water, maybe we could bring water with us, we could have a huge settlement program, we eventually have huge ships and we can move over there and bring everything we need. And these stars will be energy sources, stable energy sources, for the future trillion years of the rest of the universe. When all the stars go out, it will just be the red dwarfs left shining. And so it seems obvious that that's where civilizations would be drawn to one day live. It's a reliable retirement home, reliable long -term, good stable property prices throughout. I've seen sunshine, I've seen that movie.

54:21How much truth is there in what we can do to stars, to prolong them, to control them? Yeah, we actually have an idea in my team where we've been working on some of these ideas. If one immediate threat to in our solar system is, of course, the sun. So the sun is evolving, which means as it's maturing, it's becoming more luminous over time. When the sun, when the earth was first born, There's some was about 20 to 30 % less luminous than it is today. That's a big drop off, 30 % less luminous over 4 billion years. So if you go like another billion years into the future, that's another 10 % increasingly luminosity even a bit more than that.

54:59And then that will wreak havoc to the climate at this point. So you have to do something. One option that one of my colleagues suggested Greg Lofflin was to try and push the earth back into a wider orbit. it. So what you could do is you could actually hurl an asteroid directly just off centre of the earth. And as it hurls towards it, it will swing around, or do like a gravitational slingshot around the earth, and it will fling off in either direction. But every time that you have one of these gravitational interactions, if it does a slingshot, it basically steals a bit of speed, and it will steal that speed and go off faster than it was before.

55:35And that means the earth will change speed, it will lose speed. So you can actually modify the orbit of the earth by having these interactions. So in this case, we'd actually want to increase the earth's angle momentum, we want to increase its speed. And as you do so, it would push it out into a wider orbit. So you'd have to throw thousands and that millions of asteroids at the earth to do this. And every time you'd have to do it very close, but not just to take. So high risk strategy. It's like a very high risk strategy for an advanced civilization that really knows what they're doing. But that's where you can move the earth back.

56:08Just the right rate to keep the temperature the same. I guess you could do this for climate change as well in the near term, but I wouldn't recommend it. I think there's probably safer solutions. The other solution, there's, I think, more feasible, or at least less risky for this, is actually to remove mass off the sun. But maybe this is a bit more sci -fi, even more sci -fi and throwing asteroids at the earth. You can actually have some kind of way, like, either most simply like a ram scoop or something off the surface of the sun, but you can actually probably do it with lasers as well. You can actually excite certain modes on the surface of the sun and get material to be ejected out this way.

56:45If you make the sun lose mass, that reduces its gravitational pressure in the center. And so the core of the sun is where all the energy is produced. And it's like a thermostat, the greater the gravitational pressure from the outside, squeezing down in that core, the hotter it gets. So if we take some mass off the top, it will reduce the pressure and the oven will cool down a little bit. And And so we've actually regained. We've not caused it to expand. Yeah, I've not told you this has got less gravity. It could cause it to slightly change in radius, but it would not be a dramatic effect. So when we modify the radio of these stars, it would actually end up probably overall net decreasing the radius of the sun, because as you cool down the core of the sun, there's less outward radiation pressure.

57:31So that radiation pressure is basically, if that wasn't there, the sun would collapse into a black hole. The certain one -ster claps into a black or to a very small object, maybe not a black hole because of electron to generously pressure But it wants to collapse all the way down The only thing stopping it from collapsing down is radiation pressure like energy Sviewing out in all directions and pushing back against that against that force So if we reduce the power in the oven we make that core less powerful The radiation pressure will decrease it will actually net shrink very slightly So actually that's why if you look at stars with lower masses, they tend to have smaller radii They don't they don't actually get bigger as a result of the lower gravity, which you might think of so Overall, this would slightly decrease the radius of the Sun and the net effect would be to decrease the luminosity So we calculated a rate of doing this and it turns out to be Trying to remember the number but it was about something like a one asteroids worth like Vesta is like one of the largest asteroids as one asteroids worth of material off the sun every year.

58:31So not very much. That's how much you have to remove off the sun to basically keep it cooling down gradually over the next billion years, such that it basically doesn't change temperature. It will basically stay exactly the same luminosity as it is today. So we did this calculation in my team, and we think it's an intriguing idea, and we think that if somebody was ever going to move to the star and potentially colonize it for a trillion years, because this would be an obvious thing that they would do, and there are actually signatures that we could look for potentially to detect this. So we call this starlifting.

59:05Starlifting. I was thinking about solar landscaping, that like a solar landscaper would be a future job. Solar gardening, almost, yeah. Correct. And another idea was that my student had this idea that you know, you could also use this in the neighborhoods. We talked about supernovae being potentially dangerous. Like, beetle juice is nearby, and people are worried about beetle juice one day going supernovae and potentially, you know, it's too far away to actually really affect us to be honest, but you could have a star like this nearby. We could potentially, or a civilization more advanced than us, could potentially fly there, do this mass removal process almost as a pruning technique, right?

59:42So this star is kind of like a weed in your garden that you, like a pest that you want to get rid of. And so by stripping mass off the top, you could, you could remove that threat and declaw it and mean that your neighborhood is safe again. So it's really fun to imagine this is all what physics allows, right? There's nothing about the laws of physics would prevent somebody from doing any of this. And so if the laws of physics allow it and there's a good motivation for why a civilization might want to do it, then it's interesting to ask whether somebody is actually trying this right now. Given the requirement for water that's needed for life in any form, at least as far as we know it, what is the likelihood of underwater civilizations?

1:00:31And if you have an underwater civilization, I seem to remember learning that there's a few restrictions that those kinds of species would have, like they can't smelt iron and materials that they would be able to use to build things in the same way to be able to go to other planets. Is that something you've considered? Yeah, I mean, this is super intriguing. I've also got one of the most interesting aspects of this is the communication aspect of dolphins and whales as our sea intelligent companions that live in the ocean. And for years and years we've been trying to just communicate communicate with them, right?

1:01:06If we want to communicate with an alien civilization, we should at least be able to communicate with dolphins and whales and have a conversation with them. But we haven't really succeeded very well at that. Although it has recently been breakthroughs in this, there was a wonderful podcast on the daily podcast New York Times does that talked about some recent breakthroughs in this area. So there are some advances happening. But in terms of a whale or a dolphin or anything analogous to that ever becoming a civilization it does seem like this obvious hurdles. My colleague Adam Frank has been thinking about this a little bit harder than I have and he pointed out that oxygen is not just a problem in the ocean but it could be a problem in the atmosphere as well.

1:01:48You could be on an exoplanet that has no oxygen but you could still be a creature with thumbs and opposable thumbs and hands and things and a smart brain that you might have the idea of developing technology, but similarly you wouldn't be able to really do any industry if you couldn't burn. If you didn't have access to combustion, that seems to prohibit a huge range of technologies that were foundational to us getting started. And if people often say about fossil fuels as well, like fossil fuels are clearly a poison to our atmosphere, but had they had not been on our planet at all, it's questionable whether we would have got to a point where we'd even be developing solar panels, right?

1:02:28Because that requires some pretty advanced technology compared to Stone Age tools. You can't go from Stone Age tools to solar panels. You need something in between to bridge that. And combustion was certainly a pivotal filling in step for us in our own development. So we're getting a little bit speculative as to whether other civilizations could use other things, I think Adam Frank has been interested in alternatives to oxygen for combustion. I think he talks about hydro fluoride as a possible alternative, but that's a very toxic molecule. And so it's unclear if anything could actually survive and not be intoxicated by having such a poisonous fume for its one combustion thing.

1:03:10And also that doesn't just combust, but it combusts way harsher than oxygen does. So it would really explode basically every time you try to use it. So it'd be very difficult maybe to imagine combustion. So similarly, it does seem like having an oxygen rich atmosphere could be a requirement to potentially developing a technological civilization. But subsurface intelligence and subsurface life more broadly is one of the most interesting things we can do in the near term to look for because we have Europa and we have in Saldars, these moons in our solar system, which almost certainly have liquid water beneath their icy crusts.

1:03:48And we know we can visit them and we know we could think of ways of getting down to that surface and probing and looking for life in them. It's going to be very difficult to do so, but I think the investment is worth it because we could answer this most profound question as to whether life started in a completely different environment to that of the earth. I think if we found that there, it would resolve the question I brought about earlier as to how often does life start in general. If there's two instantiations of it in the same solar system, but under completely different independent circumstances, that essentially proves that life is easy and life could therefore start everywhere.

1:04:28So having that second data point will be incredibly important for us in our understanding of life and the universe, even if it's not intelligent. I doubt we're going to find in the city of Atlantis on the bottom of Europa. So I do imagine... We might find... We might have Euro -Pensushi in a few centuries, and the billionaires will be shipping over some Euro -Pensushi and selling that at a premium, I'm sure. But it's a possibility that I think is to be taken very seriously, that there could be life in our own solar system. And for me, that is the most likely place we're going to find it beyond the Earth.

1:05:03I suppose the only one of the potential pushbacks there would be what if there was some sort of cross pollination, how do you know that we're in the same solar system, something hit us, there was something carried on that which ceded this other moon or some other area of the solar system with the same original sort of genesis of this. Yeah, that's a great question. And that's an idea called pan spermia. So pan sperma is the idea that life couldn't transfer between planets, between moons, and spread out between within a solar system, but potentially even beyond other solar systems as well. So the nice thing about uroprinselduses that they're pretty much sealed behind this prison of this thick ice sheet, which is at least a kilometer, probably several kilometers thick for both of those objects.

1:05:54And so it's very difficult to imagine. Let's say a rock got knocked off the earth in an impact. And on that rock was a tardigrade or a whole bunch of them, a whole bunch of extreme afires clinging on for dear life. And they somehow survived the journey of space, which I think is actually feasible. They survived the impact. But even so, unless that impact is extremely massive, it's not going to crack all the way through many kilometers of ice and penetrate through into that ocean water. So I think the the child and also not only this but it's also it's further out in the solar system So you're going from Imagine like a well You know that there's coin drops that you throw coin it circles down it circles down it circles down Now you can have two coins hit each other fairly deep down in the well That's the earth the earth is pretty deep down in the gravitational well.

1:06:43It's pretty close to the Sun Jupiter's pretty far out. It's 5 .2 further times out than the earth is from the Sun and that's where the nearest one of these moons is, Europa. So you have to have a collision that is impactful enough that that rock can then circle all the way back up five times higher and then still have enough energy to strike Europa and break through the ice. It's not impossible I don't think, but it would be pretty unlikely that you would have the circumstances to create something like this. For Mars, for Venus and the Earth, there we can imagine interchange a material much more readily.

1:07:17And it is intriguing to ask, maybe life started on Venus or maybe life started on Mars and moved over to the earth and there's some transfer between us. But I think you're rope and salad us. They're almost like sealed boxes. Yeah, that's exactly why I don't know. But then that just raised the question that we might break that seal, right? Because if we deliberately drill down into it, whether we want to or not, some extreme if I was going to cling onto the side of that spaceship, you can't, it's basically impossible to completely Sterilize your space you have in space. There's always something.

1:07:49And then it's going to penetrate into that ocean and potentially be a source of contaminant. So you get that one chance of doing the experiment correctly. And if you screw it up, you've potentially introduced an entire new biosphere that could be fairly dangerous in fact to an existing biosphere there. Talking about large impacts, can we talk about the importance of the moon and its creation and stuff. Yeah, the moon's a puzzle that we still wonder about today, despite the fact it seems like it's a sealed story. We think the moon formed from a huge impact. It's thought that there was a Mars -sized planet, which smashed into the proto -earth billions of years ago, just after the solar system formed.

1:08:35So the earth would have been actually been larger than it had this impact not had occurred. It would have been maybe 50 % more massive than it is today, maybe twice as massive. And this impactor came along, smashed into the earth, knocked off a huge amount of material, and it's thought that that impactor, which we normally give at the name Thayer, would have been almost completely obliterated in this and vaporised in this collision. And then some chunk of the earth was knocked off, and that chunk of the earth is ultimately what formed the moon, or maybe even multiple moons that then coalesce later into a single moon.

1:09:12So this is a huge amount of interest about why why you might come up with a speculative idea and and still people are challenging this idea. The thing we know for sure is that the the moon rocks that were collected by the parlor, the parlorationals have almost the exact same isotropic ratio of oxygen 18 to oxygen 17 I think it is as earth rocks do. And this is thought to be a fingerprint that the rocks formed in the exact same place around the sun. We look at rocks from Mars, we look at rocks from Venus, these are basically meteorites we've collected that land on the Earth. They have distinct isotropic ratios, but the moon and the Earth have exactly the same.

1:09:52That tells us that they formed from the same inherent clump of material. That's challenging with this impactor. With the impactor, if this thing really did have its own unique origin, this impact of thea, why didn't it contaminate that then and have its own distinct signature that gets mixed in. So that has been a challenge. One idea that has been suggested to Catrite, this is called synestia, I think I'm pronouncing that right, synestia. And that's when the impact happened, it was so extreme that it formed basically one giant and donut shaped planet for a while. So the earth and the moon would have smashed together, formed basically a ball of lava essentially that was shaped like an almost a donut in space, spinning very rapidly, cause of all the angular momentum from the impact, and then gradually have peeled off and formed a moon and the earth separately from this giant impact.

1:10:47The reason why this is attractive, because it allows for this material to mix in, can thoroughly, so this impact to whatever it was, the earth and the earth completely mix into one single object and then it separates out into the earth and the moon separately. That seems to explain some of the mysteries, but not everybody accepts that idea and there's still a lot of controversy about the moon. Like the moon's far side has a very different appearance and thickness to the near side. If you've ever seen a picture of the far side of the moon, it looks radically different to the near side. The near side has these Maria, these beautiful lava flows that happened millions billions of years ago that kind of smoothed out and then it has these more created areas.

1:11:28Whereas the far side is almost completely created. There's very, very few Maria. That's because the crust, the actual lithosphere of the moon, is much thicker on the far side than the near side. And again, that's weird. Why should that be? Why is there a dichotomy like that? And so one idea of there is that actually two moons formed in this process and then one kind of pancake onto the back of the No way The mood should go today And that is that pancake that then formed like a thicker shell on the far side of the moon So there's it's like I wish we had a time machine because this would have been like the greatest fireworks shown in the universe to have seen the formation of the moon And again it raises so many questions like how How unique was that?

1:12:12Does that happen in other exoplanet systems? Are we special that this happened here? We don't really have any observation or evidence either way, but obviously my team and I, one of the things we've been trying to do the last few years, is to try and detect moons around other planets, to try and ultimately answer this question. Because at the end of the day, the moon has a huge influence on our planet. It stabilizes the ability of the Earth, it gives us the tides, it gives us the rise in the fall of the tides, which potentially are a useful thing for life. They create rock pools on the coastlines, especially when the moon was closer in.

1:12:47It would have formed, you know, constant covering tides, basically. The entire continent would have been covered in a massive tide. They would have formed all these rock pools all over the place. It also potentially stripped off the upper mantle, the upper lithosphere of the earth. And that could have been used. So basically the crust. So the crust may have been much thicker of the earth when it first formed. And then the impact could have ripped off some of that thick crust. And had that not had happened, the crust may have been too thick to have allowed for plate tetonics. So plate tetonics we think are absolutely crucial for life, as light life as we have it on the earth, because they allow for something called the carbon cycle.

1:13:28So when an animal dies in the bottom of the ocean, its carbon is locked up in its bones and its shell, whatever it is, and it settles down to the bottom of the ocean, it just stays there. And if there was no, if that was just the way it was, the world would run out of carbon, basically, and there'd be no way for animals to grow on the surface anymore because there'd be no carbon left. But instead what happens is these plates subduct and they go under each other, and so that carbon recycles, it comes back out in CO2 in volcanoes, and that allows access for photosynthesis to happen in plants, for instance.

1:14:00So without the carbon cycle, it's difficult to imagine how we'd have the biosphere we have today, and the moon may actually be the reason why we have a carbon cycle. For a vet had not stripped off that upper crust, the crust would have been so thick that we would have formed what we call a stagnant lid. A stagnant lid is what seems to be the case with Venus. Venus seems to have a very thick lithosphere which basically prevents plate tectonics as we have them on the Earth. So, yeah, very intriguing. Like, you look at all the things the moon does and you think, Wow, are we a product of the moon?

1:14:38The idea of plate tectonics kind of kind of, like doing global telling is so fascinating. And yeah, I mean, the moon being tidally locked or rotationally locked, what's that called? Yeah, tidally locked. Yeah, tidally locked. Yeah, so we only ever see, how rare is that? To have something that doesn't rotate at all. That seems bizarre. That's pretty common. A lot of meanings, that's true, because we think we understand why this should happen. Whenever you get fairly close to a planet or a star, the gravitational effect obviously increases as you get closer and closer, and it locks in the shape of that object to always have one side facing it.

1:15:25Especially if you have some kind of fluids like the earth does, these tides can be quite effective at slowing things down. It happens for many moons around Jupiter, Saturn, so we think this is pretty common. It's thought that there should be common for exoplanets as well, which is interesting, but again, unproven, but we think that there are some stars which have very close in planets, and those planets are so close that they should tidy lock to their star, and we've measured many of these hot Jupiter's and we've watched them whizz around their star and we can even see basically thermal maps. We can kind of re -thermely map the distribution of energy on these planets and they look indeed like they are tidy locked as we would expect them to be.

1:16:09So everything about exoplanets seems to support this idea that tidalocking should happen. But there are also mysteries of tidalocking. We don't really know exactly when it stops. The theories of tidal theory that we use are fairly primitive to be honest. They kind of parameterize things in a very basic way. Ideally you would just simulate an entire planet like every single atom, but we just don't have computers powerful enough to simulate every single atom. So we use these simplified models and we know these simplified models don't always work. So for instance, for Mercury, it was predicted that Mercury should be tidied up to the sun, but it's not.

1:16:42It's in a pseudo synchronous orbit. And probably the reason why that's happening is because of general relativity. Because actually there's general to stick effects that come into play when you get close to a star as well. So it's thought that tie -locking should happen, but in some instances, it's more complicated than just a simple formula, and you really need to think about the composition of the star, the composition of the planet, what it's made out of, does it have a core, what's its density profile, like how much general relativity kicking in here. So the calculation is quite non -trivial, but it does seem like it's common in the solar system and expected to be common elsewhere.

1:17:19Are there any other interesting rotations of planets in our solar system? Yeah, I mean, one of the things I think it's interesting is Uranus is tilted on its side, which is like kind of confusing. So even though it's spin isn't particularly unusual, it's somehow been knocked over, so it's just spinning in a sideways configuration. Like it's rolling forward? It's like it's just, it's access in which it spins.

1:17:46Like orthogonal to its orbital plane. So normal to its orbital plane pointed up if you like. Whereas for Uranus It's kind of tilted so that it's North Pole is pointed at the Sun. So I'm rolling forward on a surface that doesn't exist. Yeah, kind of. Yeah. And as it goes round, what's kind of weird is that the moons are also tilted over alongside it. So this has been like curious how we can imagine maybe the planet getting knocked over on its side. but then wire all the moons also on its side as well. We don't really understand what happened there. So very strange to understand how for Uranus. And then one of the cool things we're thinking about a lot of my team at the moment in my research group, the Cool Words Lab, is the rotation of Jupiter and Saturn, which rotates in pretty fast, once every 10 hours.

1:18:35And we think this is to be expected pretty much for all giant planets once you get fire and a foyer from the star. So if the, if Jupiter came too close to the sun, that tidal locking thing would cook in, and it would slow Jupiter down. It would put the brakes on Jupiter's spin and slow it down to day's rotation rate, basically whatever it was all but appeared it was. But Jupiter's final for way, that it still retains what we would call its primordial spin. And Jupiter and Saturn don't really have any way of getting rid of that spin. For the Sun, it does lose spin. It was probably spinning much faster when it was young, and it's been losing it through its very strong magnetic fields.

1:19:12Jupiter has many fields, but nowhere near strong enough that it can lose spin the same way the sun is. And it does. So far away from the sun that it's not going to be slowed down by being closer. Yes, correct. So it doesn't really have any way to shed this spin. That's interesting because we are now, we have some observations coming up with the James Web Space Telescope in October where we're going to basically measure a Jupiter analog. So a planet, an exoplanet around a different star, it's over a thousand light years away, but we're going to measure very precisely its shadow as it passes in front of another star.

1:19:43And we think that this planet should have, similarly, a fast spin. And why that's interesting is that that fast spin causes Jupiter to bulge out at its equator more than its pole. So it's actually 5 % wider than it is tall. And Saturn's 10 % wider than it is tall through this spinning effect. We think we can measure this. It's never been measured before. If we can measure it, it will tell us basically what the plan is made out of, how fast it's spinning, and even it's tilt angle. So as I said, Uranus is tilted right over. Jupiter and Saturn are not very tilted compared to that. But we should be able to actually measure the angle for the first time and really get a deeper insight as to how these plans are forming.

1:20:24So I'm just excited that we might have access for the first time thanks to James Webb to a completely new observational technique learning where exoplanets we have their mass we have their radius but now we can get their spin their bulgey nurse their tilt angle and really just complete the picture as to how these things formed. Are most solar systems and galaxies on a kind of a plane? Why is Why are things not spheres? Why is there not sort of three dimensions of movement? Yeah, that's a great question. You might think of that as being an obvious possibility. And certainly there are actually some plants which do that Chris.

1:21:03So it does happen sometimes that you have plants in these wild chaotic orbits. If you look at Jupiter as like a mini solar system, it has these four inner moons, the Galilean moons as they're caused, that's Io -Europa -clister -ganemede. And they look like a mini solosystem, like a pizza, like a flat disc. But then around that, you have this nebula of spherical orbits basically. As you say, like just stuff in all kind of crazy directions. We think that all of that stuff, in the wild orbits, is what we call irregular moons, and the stuff that's close in and form like a disc, we call it a regular moon.

1:21:38So we think the regular moon's formed basically from a disc of material that was around Jupiter when it first formed. So as it was forming, it was spinning and collecting material. And just like spinning a pizza, a piece of dough, it naturally wants to form a disk through that anglementum. And then from that disk, the moons just coalesced and popped out. But the irregular moons, they kind of formed that way. So we think those are probably asteroids and even minor planets that were captured by Jupiter's gravity. So that's more like the three -body problem type stuff. That's instabilities that kicked in, then Jupiter got in the way and kind of dragged them into these wild orbits around themselves.

1:22:15And we do see in some exoplanets, planets doing very strange things like that. There's even many cases of planets orbiting backwards around the star. So the stars spinning, saying a clockwise sense, and the planet goes around, sometimes even in a plane, but in the complete opposite direction, which is we don't have that in the solar system at all. That's very, very odd. And that has been a big headache for lots of people trying to understand how these things form, how on earth do you get upon it to go around in the complete opposite direction? So is angular momentum the explanation for why most things seem to be on a plane?

1:22:51Yeah, I mean, discs happen all over the universe like think about Saturn's rings. It's in a disc. Think about the galaxy. It's in a disc. And think about, you know, when we look at young stars, we see discs around them. They're actually, we've taken photos of them. We see these discs forming. So essentially things as they spin, that angriamentum wants to spread material out into a white disc. Is it possible to know the size of the universe outside of the observable universe? Is that something that we can answer? That's a hard question to answer because of the fact we can only see so far. So when we look out into the universe, the greatest distance we can see is just how long light has had to travel given the age of the universe.

1:23:35So you might now heavily think if the universe is about 13 .8 billion years old, the furthest distance we could see would therefore be 13 .8 billion light years away. However, the distance actually much greater than that because the universe is expanding. So during the time this distant object produced a particle of light, a photon towards you and it travels that distance, that that origin point has itself moved further and further away from you. And so due to the rate at which we think the universe is expanding, the most distant point that we could possibly see, which would be 13 .8 billion light years of travel, would actually be probably something like 45 billion light years away to do that expansion effect.

1:24:23So therefore you have 45 billion light years in one direction, you could do the other direction another 45, so that gives you a diameter of about 90 billion light years. So we can say the universe must be at least this big because when we look out in that region, we don't see repetitions. So we don't see if the universe was like on a sphere and you just traveled around the sphere over and over again, you see the same stuff happening over and over. But everything in the universe seems unique. Every patch seems a different patch, trivory or else. So the universe seems to be at least 90 billion light years in size.

1:24:56But it's probably much larger than that, because when we look out at that distance spec, there's nothing fundamentally different about it, and presumably from its perspective, it could see another 45 billion light years again in the direction. And so the question is how many times can this go before there is some kind of wrap around? Or perhaps there isn't a wrap around, it just goes on forever. So this really speaks to the curvature of space time. Like what is the shape of it? Is it indeed totally flat? If it was perfectly flat, then the universe would essentially be infinite. In every direction, you could just travel and travel and travel and you'd never come back to the same point.

1:25:32It doesn't mean necessarily that the universe in terms of matter is infinite. There may be a region where all the matter and energy lives, and then eventually you just exit that region. You're still in space -time, but there's just no stuff anymore. And then eventually you might travel far enough away and you'd hit another universe if you like, another region of mass and energy that's completely separate from that of our own. But generally, I think we assume that that's not the case that it's just kind of homogenous everywhere by the cosmological principles we call it, we kind of assume that where we are is typical of everywhere else.

1:26:07There are some measurements trying to constrain the curvature of space time, especially using Gaia. You can essentially So like draw triangles on the sky and add the angles up of those triangles. And if you draw a triangle on a flat piece of paper, the angles should add up to 180 degrees. But if you imagine drawing a triangle on a balloon or a football that's curved, the angles will actually add to an angle greater than 180. And so you could therefore tell that there's some curvature based off that sum of those angles. So we can do a similar kind of experiment in astronomy. And as far as we can tell, the angles do add up to 180.

1:26:43The flatness of the universe is very, very flat. It may just be though that like, you know, our early ancestors who looked out at the horizon, and they saw what seemed to be the flat earth, right? The earth does look flat. But if you travel far enough and you get a tower big enough, you will eventually see the curvature. So it may simply be that the curvature evades us and there is a curvature, but we just are not able to see it yet. But it does imply the universe is very, very, very large, much larger than that which we see. And it is potentially and mind -bogglingly infinite. What would the implications of that be an infinite universe?

1:27:26In a sense, there's no implication, and in other senses, profound implication. So in a sense, there's no implication, it doesn't really affect anything outside of the, this barrier, as far as we can see, 13 .8 billion years of like travel time, or 90 billion years when you convert to the diameter of this physical scale, anything outside of that Hubble volume, as we call it, can have no interaction or effectiveness in any way. So there's no way, if there was a maneuver and alien out there who could ever affect us, there's no supernova, which could go off, there's nothing which can ever happen there, ever in the past or the future, which can influence us.

1:28:05And so in that sense, it doesn't really matter what's happening out there. So it's like, if a tree falls in a forest and no one's around to hear it, does it really make a sound? It's like, does it even really matter? It philosophically, does it matter whether this stuff is out there? And if you think about quantum interpretations of the universe, they, some interpretations would basically say it doesn't even exist. If It's not observable. It's superposition is basically completely ill -defined and you can't even talk about it being a physical object in a sense. So, there's that kind of perspective of it, but another perspective is profound because if the universe is infinite and not just infinite in scale, but there's mass and energy all over the place and there would be an infinite number of creases and an infinite version of David's out there.

1:28:52And with enough like monkeys typing on a typewriter, infinite opportunities, everything will happen again and again and again and again and again, an infinite number of times and sometimes they'll be slightly different, sometimes they'll be exactly the same. And that's a strange concept. It means none of us ever really die, right? There is someone who has the exact same life experiences you, who is you in every measurable sense of the word, down to the atom, down to the electron. They are the same as you. And yet they could be offset 100 years into the future, or 100 years into the past, or whatever this really means in terms of time, because we're such wide separations at this point.

1:29:32But we would all basically be alive forever somewhere. So you can get into kind of like metaphysical, philosophical aspects of it, which are which are very strange to Pundra as well. Yeah, it's a... I'm writing saying that there is, I don't know what the cubic meter space that I inhabit is, but there's only so many ways that matter can be arranged inside of the space that I occupy, and if you have an infinite universe, therefore there must be at least at some point this. Is this not Boltzmann brains? Is this not something else as well that kind of ties in with that? Yeah, it's a similar argument to the Bolson brains.

1:30:10The Bolson brains argues that it's really thinking about the far future, typically when people talk about Bolson brains. But if you imagine time running forever and ever into the distant future, then random particles will sometimes coalesce in random ways to eventually form a conscious brain. And what's kind of strange about that idea is that the conscious brain doesn't even have to exist for very long. It could exist for just a microsecond and then fall apart. But in that microsecond it could have all of your memories, every experience you've ever had would be hard coded into its wiring. And so it would believe it was in this room.

1:30:48It had had all the experiences we had had. And it would be indistinguishably, there'd be no way to disprove that. And in fact, when you really think about the infinities involved, there's far more boxman brains than there are rational human brains. It's far harder to have a human go through all the steps of actually living a life. It's just to emulate the life. And so by that account, it's much more likely you'd be a Boltzmann brain. The original simulation hypothesis. Dear God. Right. It is kind of like simulation hypothesis. But a lot of astronomers have turned very sour to this idea. And a lot of the arguments against it fall into like entropy camps and that, you know, if you really look at the far future of the universe and look at the heat death, you can't just have entropy reversed like this, and even in spontaneous ways, in a probabilistic sense, it just really shouldn't happen once you get to these kind of extreme times where the particle density drops down so much, each particle eventually will just be in its own universe, so it can't possibly coalesce into these Boltzmann brains if it's the only particle around.

1:31:50So when you think about the practical implications of the cosmological model that we think is most likely answer for the future of the universe, the Boltzmann Brains idea starts to fall over a little bit. Have you read the five ages of the universe? I haven't. No. That's the Fred Adams Greg Lofflin book. Oh, I know. I probably know the paper because they wrote a paper which is the deep time of the universe. And that's a classic paper that I've given to most people many times. It talks about, yeah, the decay of the proton, the far future of how the last stars all go out and the possibility from New Star.

1:32:31I know the paper quite well. I haven't read the book. This is like the normy translation, probably, of that paper. It's just, I think it's maybe 25 years old. Now, in the 90s, I think the book was written. It's written excessively, but it's have you going for a muggle like me? But I love thinking about far futures. I absolutely, there's something so awe -inspiring and dreadful about it. And it's in the same way as spatially looking up at the night sky makes you feel small and insignificant. This is the same, but doing it with time, like your tent -for -a -ly insignificant. And yeah, just thinking about how much further they go ahead.

1:33:16You had that beautiful story. I must have listened to it five or ten times, the one about the civilization that waits until the very, very final stars are going to die. That stuff to me, far futures thinking is one of the coolest thought experiments to do. Yeah, it's a bizarre concept to think that we are at the beginning of the story. It kind of feels Because like everything is often presented to us as we should treat ourselves as mediocre. So if you're born in a random country, it's pretty unlikely you're going to be born in a tiny country like the Virgin Islands or something because it's just the population is so tiny there versus being born in a country like United States or China or India or something.

1:34:02You're much more likely to be born there. So that's the mediocrity principle. But when we apply the mediocrity principle to time, it just doesn't work. So the history of the whole universe should stretch out for trillions and trillions and trillions of years even you know 10 to the 10 to the 10 to the 10 type years we're talking about here and We live in the not just the first chapter and not just the first page but like the very first like a letter of that whole story and that feels really odd it feels incongruous with our Expectation that we should be typical and we shouldn't expect to be special and yet when we look at our timing it is clearly very special.

1:34:40And there's no reason why in all of that in a vast, deep future, we couldn't arrive much, much later in the story. You can imagine, as I said, these red dwarfs, which will live for trillions of years. Why shouldn't they have planets and liferine them for a very long time? In that paper, and I'm sure the book is well -greg Loftin talks about the idea of brown dwarfs, colliding together and birthing new stars. And that'll be a very rare event, but over the vast, vast epic of time, actually form a significant population of stars, which form. And in all of that deep, deep future, Boltsman Brains, it seems odd that we would live right at the very, very beginning of the story.

1:35:22And I think about that a lot, I'm trying to make sense as to what it means. It seems to suggest that either our idea of mediocrity is fundamental mental or wrong that we should not assume we're in the middle, that maybe it's okay to assume we're special in this sense, which is strange as that sounds, or perhaps there is something about the deep future, which is inhospitable. The universe, there's two ways that the universe could just become inhospitable over time. And it may be not necessarily through stars, because we think there'd be plenty of stars, but maybe a roaming civilization, just like a vibrant.

1:36:00Who was up all planets which could potentially have life? That would actually work really well as explanation. If a roaming AI went around the universe and it happened spontaneously in many different parts of the universe at a certain amount of time, an AI just arrives and it spreads off and it just knocks off everything and it just converts everything into computers. And it would actually make sense as to why we lived when we did in history of the universe. Or if there was another catastrophic event like the universe went through like a false vacuum decay event, which essentially means the universe itself becomes unstable and we have almost like another big bang type event in the next 10, 20 billion years.

1:36:44It's kind of improbable when you do the math that should happen. But that again would rationally explain why we live when we live. And so the mediocrity principle does seem in strong tension with this chronology. And I think that's probably why you and many others and myself include get so in it, so alluring this idea and so something about it, something profound here, there's a lesson and we just can't quite see what the lesson is, but there's something here for us to pick apart and there's some deep truth that we're missing that this is telling us. Is there not something to be said about the rate at which new stars and therefore planets are being born that that will sort of drop off over time?

1:37:25Therefore being shunted toward the start is more likely. It's kind of more fertile ground. That's only true. So, suddenly, star formation rate is already in decline in agar, in agaroxy. It's already in decline. So, the peak of star formation rate has passed, which is already kind of sad, right? The good times have peaked in terms of the economy of the... We're in a stellar depression. Yeah, right. Kind of depressing to think of it that way. But despite that, there's just so much time ahead of us that even if you reduce the rate to 10 % of that which is now, that if you have a trillion times longer to go, you're still going to have like a lot of stars.

1:38:09So even though there is a peak, it's not a symmetric peak. I guess that's the thing to get your head around. it's a very, very long tailed peak, and it takes a long time to decline all the way down to zero star formation. And so if you actually add up how many stars live in the tail of that distribution, there's far more stars than planets born in the tail of the distribution than there are born at the peak of the distribution. And so then it gets really curious, like why, why, therefore, should civilizations also be correlated in their birthrate to planets? So you might expect that naively to be true.

1:38:47How right is it to say that we would be one of the first civilizations to come about, assuming this sort of mediocrity principle, but then also I've heard that stars and planets have been born, lived and died many times over before ours was even created. Therefore, we should see some civilizations out there that they've had chance to get to where we are and way beyond. Yeah, it's only a way of resolving many puzzles. Like why do we not see a galactic empire spanning the galaxy that has done this star -lifting thing we talked about earlier or just converted stars into giant machines or built infrastructure or have starship lanes across the galaxy?

1:39:33We don't see any of this. We have been doing setty for 50, 60 years and we don't hear any radio signals from other parts of the galaxy either. I mean, there's possible there's someone out there, but they're very quiet. It's not a chattory, loud galaxy out there. And this raises a puzzle, like it may be one explanation. This is really the Fermi paradox we're talking about now. One explanation is that we are the first. And not only would we be the first, that would necessarily imply that intelligent civilizations are very, very rare, right? Because the galaxy is already 13 billion years old, almost the same age as the universe.

1:40:08So that implies that it's a one per 13 billion year event, which is incredibly unusual then if that was the case. So it is possible with first, I tend to lean more on the idea that I think lots of, if there is life out there and civilization start there, I think getting to this point is not that hard. I think it probably does happen. But the real question is the future for us, the future of humanity, whether we can continue on this path that we've been continuing on, in a, in a, this is unsustainable trajectory that we've frankly been living in over the last few centuries, certainly. It seems questionable that we can keep doing this.

1:40:49One way to resolve this is to try and live in balance with your planet, of course, and try to be like a more sustainable civilization. I think having, you know, as well as with nuclear weapons, like having nuclear weapons, is just immediately unsustainable, because as long as there's a 0 .00, whatever it is, percent risk of someone clicking the red button each year, given enough time, it will happen. It's just the same thing. Like given enough time, there will inevitably be a nuclear war as long as the nuclear exists. It's just a question of when, not a question of if, it's just going to happen.

1:41:23So that's already kind of terrifying. And really, what we're doing to our planet is kind of similar. We are affecting the habitability of our planet by this huge experiment of modifying the chemical composition or atmosphere. And that's also kind of concerning. It might, not, I don't think it's going to cause an extinction event for humanity. I'm not a do -missed in that sense, but I do think it would probably put pressure on our economy. It'll mean we'll probably take resources away from science, from, you know, exploring space, and I think we'll become more and more insular, and then you can kind of imagine why civilization would never spread between the stars because they get so distressed and so hung up on just keeping alive, basically, and trying to maintain some level of comfort level to what they're used to, that the idea of spending 10 % of your income on something which might seem frivolous like building a moon base or a Mars base just becomes a lower and lower priority.

1:42:20And certainly that's happening with our own budgetary definitions over the last sort of five, ten years or so, we're seeing less and less money go to basic sciences in the United States. And so this is also a worry that it could be that very, very slow decline. And I think that could be a possible explanation for the Fermi products that this happens quite often. Civilizations, they're inherently unsustainable, and they run up into themselves, and it's themselves that are the ultimate threat to their own growth. But on the other hand, that means that if someone cracks this and they do become sustainable, we probably would never see them.

1:42:55Because someone who is completely sustainable would be invisible. If you're in complete equilibrium with your planet, then there's nothing to look for. I mean, if we want to look for a civilization, what do we look for? We look for the solar panels because that's in DC equilibrium with the planet because that's not the natural material on the surface of the planet or you would look for a nuclear bomb going off. That's in DC equilibrium with the natural state of the planet. But if a civilization truly reaches a completely 100 % sustainable state, there is no signature to look for that would be indistinguishable from a natural perfectly natural biosphere.

1:43:33So that's intriguing. We may not be actually detect those civilizations because they're so good at looking like a natural planet. Given the time that you spend thinking about potential futures for civilizations, the ways that they may or may not be in equilibrium, does it give you a... an additional sense of seriousness and trepidation sort of about what whatever we do here on earth, the fact that you kind of can see cosmically, galactically this sort of knife edge of just how easy it would be to not end up keeping going the way that maybe we would like to. Yeah, I think it's such an awesome responsibility when you think about the pressure of just existing in a way as a species.

1:44:24It is, you know, I think that's my own life a lot and maybe you do as well that if you've played computer games growing up when I said I did, it does feel sometimes that life is a bit like a computer game. Like it's kind of wild and in a computer game, you realize there's certain rules and you realize what you're allowed to do and what you're allowed to do. it's kind of sometimes a little bit crazy that you actually I could like complete the game. I could basically finish the whole thing. I could you know, build this massive city or massive empire, whatever it is you're playing in the game. And life is kind of like that.

1:44:55When you realize the rules of the game, you realize there's nothing really stopping you from completing everything you want to complete in the thing. And I think as a species, it's wild to think that we have that. As far as we can tell, The rules of this game that we're playing do not prohibit us from one day Colonizing the entire galaxy if we wanted to there's nothing in the game that prevents us from doing as far as we can tell There's nothing that prevents us from having a civilization which would last for a trillion years of building wonders that would you know light up the universe essentially and Yet none of that has happened and so it is it is interesting that we have this awesome power as we still have free will, I believe.

1:45:40I still believe in free will and choice. And so I believe that we have the opportunity, if we decide to take our civilization wherever we wanna take it and become that dream civilization, or maybe whatever it is we have, for me, maybe it is a civilization that spans the galaxy, maybe few, it's something else. But whenever that dream is, we can achieve it. And so that just reframes for me a little bit, the power we have. I think we often feel powerless, us. But when you realize it's just these rules and there's nothing in the rule that prevents this, it's exciting. It means it's up to us what we do.

1:46:17It's still our choice, what we do with this planet, what we do with our society. It's all up to us. There's a lot of responsibility that comes along with that. Yeah, it can feel sometimes paralyzing and then crushing the weight of that. like, wow, I could, you know, if you were told you were child progedy and therefore you're expected to become the greatest genius in Einstein, that could feel like an enormous pressure. You can only fail from that. Yeah, to live up to your father's expectations, as many of us have felt that that pressure, but there is no father that this is just us. There's no, no one's expecting us to do anything because it is just us.

1:47:00We're in a game, it's a one -player game. It's just us in the game. There's no one else out there as far as we can tell. So we can do whatever the hell we want to do. And if we want to destroy our planet, we are totally capable of destroying our planet. If we want to live in squalor and have a terrible economy and society and burn the environment down, it is within our power. But it's equally within our power to do something completely different and have the future that we dream of. That's what I believe. And so I've always found that uplifting, actually, that we have the agency, as the keyword, the agency, to be whoever we want to be both personally as individuals, I think, but also especially as a civilization, but it's a collective agency to work together to form whatever we want to form.

1:47:49Yeah, that's the coordination problem, right? It would be, what a shame it would be if we jump through all of these evenly spaced insanely unlikely, suburb of the galaxy into having the moon that's tidally locked into, having the sun that's the right size and where the right distance and then the pro -criotic life into the eukriotic life and then all the way up, all the way up, all the way up, and then tribal biases and in -group out -group signaling and you know, it just the fight, what feels like the final hurdle before you go, because I'm going to guess, this would be an interesting question, I suppose, that if we were to get ourselves to something close to multi -planetary life, how big of a step change in our long -term survivability odds do you think that that makes?

1:48:43I think a significant one. It's hard to put a number on that. I think that it would obviously save us from certain threats that we could either put ourselves into the earth or could come from out with forces. So now, that would force might be an asteroid impact. Most obviously, inward forces could be some kind of massive conflict or a virus or something like this. So it certainly provides some fencing off of that kind of danger. But of course, there are other threats beyond that. I mean, we all know that with COVID, it wasn't self -contained to a single country, right? And so if there was a virus, whether it's a mind virus or a physical biological virus, it still would most likely have vectors to spread to neighboring colonies, even in the solar system.

1:49:31That would, this seems quite plausible that the entire solar system would still be in danger of suffocating by such a threat. And of course, an outward threat could be a supernovae or a gamma ray burst, which would equally put the whole solar system at risk. So it's definitely an advantage, but it's not enough. If your sole priority is to perpetuate the flame of consciousness, as Musk would say, then you'd want to not just be into planetary, but into stellar, to truly achieve that, and even eventually into galactic to achieve that. But then you have to question, why hasn't a civilization done that?

1:50:08Because as we say, we don't see evidence for regions of the stick guy, which have been colonized in this way. Although perhaps they're just doing it in such a way that they don't want to be detected or hiding from us in some way. But as far as we can tell, this kind of empire building doesn't seem to happen very often. But I would hope that we can continue to keep this consciousness going, because I think there's so much, It's such a boring universe without it. I think it lights up the universe to have some some thought and some agency in there. Yeah, I agree. I Again, every time that I think of the potential far -flung futures of what we could be really helps to give perspective.

1:50:50It really is kind of the sort of philosophical imaginative equivalent of looking up at the night sky and making yourself feel small and putting your problems into perspective and realizing just how much you should probably be thinking of a broader horizons in all directions in all different types. And it's oddly, existentially reassuring, I think, in some ways. At least I find it, I find it as. Yeah. Yeah, one of my colleagues says about time a little bit as well, and he said to me, I think with our lives, sometimes individuals, we feel this way that I'll get to this point, and then I'll be happy.

1:51:28I'll get to this point, and then I'll do this. There's always like that thinking of the future as a point of rest or a point of achievement. And one of my good friends, he said to me, you know, this is it, like you're, you're in your 30s, this is life right now. Like don't, don't let life slip you by because you're so focused on the future. And I think as astronomers, I tend to live especially in the future because we think about this deep time. But don't live your whole life thinking about making sure obviously it's important to have enough money for a time and then be comfortable with things like this.

1:52:02But don't obsess your whole life about that because you're you're miss out on what's happening right in front of you and somehow being present and and seizing what's in front of you isn't is an equally important lesson because at the end of the day life is incredibly short and I'm turning 40 this year and that's like making me think like wow like where's the last 10 years just gone like that just disappeared under under the abyss And you do start to realize that like, this is it. You only get this one life and it's going by pretty fast and you don't wanna mess around. There should be a sense of urgency, I think, in your life.

1:52:42That's how I try to live my life with a sense of urgency that every day is kind of precious and matters and you're not gonna get a second chance at this. Yeah, I love that. Can we talk about my new favorite pet obsession, which is ton 618? It's this massive galaxy or massive star. It's a black hole. Oh, the black hole. Yeah, I don't know too much about this black hole, though, to be honest. I think it's just the biggest one that's being logged. But when you look at the size of this thing, I think it's, it's eventorizing is larger than the orbit of, it's basically larger than our entire solar system.

1:53:19Like this thing is just beyond beyond, like our Gantuan from interstellar, basically. Yes. Yeah, yeah, yeah. just beyond obscene. And the more that I learn about the again far futures and then looking at black holes and kind of the very odd way that they break much of the intuitions that even someone that knows this little about me as me about physics has, they're just so fascinating. Like the unanswered questions about black holes are just beyond fascinating. Well, there's such bizarre objects. I mean, they really seem like a nightmare that's come to real life. They're so strange, like a hole in space -time, and many people include Einstein didn't believe they were possible until we really started to see more and more direct evidence for their real existence.

1:54:09So they're very strange, and I think the massive ones have been a puzzle or mostly in context of what astronomers, research astronomers are talking about, the most common thing I hear about with massive black holes is the puzzle of how they got so big, especially as fast as they seem to have got that big. So when we look at the images from the James Webb Space Telescope, we do see evidence of massive black holes, what we call quasars, these active galactic nuclei, which basically fed, so this material falling into the black hole and it forms these very powerful jets, and we can see these jets and that allows us to kind of weigh how heavy the black hole likely is.

1:54:46And we see evidence for black holes which are just so large in the early universe that it doesn't seem possible that there was enough time given the age of the universe then to have built something that big, that massive. And that has been a puzzle. It's simply for galaxies as well. You know, galaxies and black holes tend to go together for the supermassive black holes. It's kind of an open question like a chicken egg problem as to what comes first. Is it the galaxy that first forms in the center you end up with a black hole or does the black hole come first and that leads to a seed to the rest of the galaxy or maybe a bit of both maybe a bit of both is going on, but certainly when we look at these early images we're seeing evidence of both unusually massive black holes and galaxies in the early universe and it's puzzling that the universe can form stuff this fast.

1:55:33There are some ideas around this that are maybe a bit more exotic that people are floating around like one idea is a primordial black hole So this is something which could have actually formed from essentially the conditions of the big bang itself so very soon after the big bang There's it's a very dense soup right the universe when it first formed and it gets less and less dense as it expands And so maybe some of those densities are a little bit dense to the others little pockets and those pockets could collapse down and form black holes directly, no stars involved, just from the raw material of what came out of the cosmic super -the -big bang.

1:56:10And those things could be potentially both very big and very small. They could even be earth sized, earth mass, black holes, or they could form things, or they were able to turn 618 -gargantuan -style black holes as well. So people are struggling and they're reaching a little bit for some of these more exotic theories right now. and we have many surveys still planned with JDST, it's still only two years into its sort of 20 year mission. That's hopefully got ahead of itself. And so this is definitely an area of active research right now. And I don't really wanna predict what the answer will be at this point because it's hard to tell.

1:56:48I don't think a lot of people saying we should rip apart models of cosmology and I don't agree with that. I don't think the Big Bang theory is fundamentally wrong or the models we use, we call like the standard model of cosmology essentially, is fundamentally an issue. I don't think you have to throw that out to explain these things, at least not yet. And I think astronomers have very good reasons to not want to do that, because then how do you explain the fact that it explains 999 other things perfectly? Like that's really, how do you explain all that other stuff so well, so perfectly well if you throw out this model.

1:57:24So I think it's probably issues of, you know, some of the early galaxies, especially that were being discovered, it was actually the star formation models were probably in error. So we take the rate of how we think stars form and we take the local star formation rate of what we see around us as kind of a proxy for that. So you say, if you have a certain amount of density, a certain amount of gas, you expect to form this number of stars. And we see that around the solar system locally. And then we take those models and we extrapolate them onto these very, very distant galaxies on the side of the universe.

1:57:58And reasonably, astronomers have pointed out that's probably not a good idea because why should we expect the way in which stars form from this mature metal rich, you know, very old gas cloud to it all be similar to the way that the very, very first primordial stars formed and when you modify your models to account for those differences, you actually can explain where these early galaxies came from. So I think it's probably an issue of not the fundamental cosmology being wrong, but the way in which we think that stars and black holes form within that cosmology, probably being needing updating.

1:58:39At least I hope that's the case, because if we have to throw out cosmology completely, it's both exciting, but we make problems. It's a big headache to explain all the other stuff that it works so well for. Do you class yourself as an experimentalist? Is that sort of the camp within which you sit? Yeah, you know what? I don't like labels at all. So maybe a bit controversial in the sense, but a lot of astronomers, maybe astronomers are a label I'm okay with, but a lot of astronomers would would split themselves up into categories of theorist, modeller or observer. There are probably your three categories of astronomy, a theorist, modeler or observer.

1:59:16A modeler kind of sits in between those two, the theorist who do pen and paper, math, and they're working stuff out on the blackboard. The observers who are going to the telescope collecting data, and the modelers who are trying to connect the two worlds to each other. And I do all three. So that's why I don't really like a specific label. And I also just think in general advice I give to students is that it's not useful or conducive to work with such a label. If you tell yourself you're an observer, then it's like someone saying, I can't do math. I hear this all the time. There's so many students who come into the classroom and say, I've never been able to do math.

1:59:52It's all gobbling up to me. And if you approach the world with that mindset, then of course you won't be able to do math. It's a self -fulfilling prophecy. You've predestined that you can't do math. And so I think calling yourself an observer can have negative connotations like that. negative self -contentations that you think, therefore, I can't do X, Y, or Z. So I prefer, personally, to really not work with those labels, not because I'm trying to be pretentious, but just because I think it doesn't serve any purpose for me, for me, think about the things that I can and can't do. And even with astronomy, I'd prefer not even to really be an astronomer, because I like a bit of philosophy, I like thinking about astrobiology, I like thinking about the connections to biology in the chemical world as well.

2:00:40So I don't really want to be unsacistics. I'd write a lot of just almost pure statistics papers. So I don't want to be in any one camp. And I think that's how it wasn't in a back in the day. There was just these polymaths that just worked on everything. And that was beautiful because they could see connections between things that you would miss. And if we live in an academic world right now that really promotes extreme specialization, you know, not only are you an astronomer, you are an exoplanet astronomer. an exoplanet astronomer, an exoplanet atmosphere astronomer, and only an atmosphere astronomer, you're a cloud astronomer.

2:01:16It gets like more and more niche, and like literally I'll bump into students at meetings and postdocs who will say, you know, oh, I'm a cloud specialist, and that's great, but you know, don't you think about other aspects as well, because how, if you're not thinking about the chemistry in the surface, how can you possibly connect that to the chemistry the atmosphere. All these things are connected to each other in some way. So, yeah, a bit of a rant there, but I just don't think it's particularly useful personally to operate with a label. And it's kind of one of my pet heaves that in the world of academia we have become overly specialised in niche and our interests.

2:01:56Yeah, that's a specialisation being for insects. I spoke to Eric Weinstein I'm twice about this. I remember I spoke to Sabina Hassenfelder a while ago about this too. It seems to me that the theoreticians, less maybe so on the astronomy side, but as I'm hearing you speak today, it's so evident that there's just tons of cool, interesting stuff that's being found out, that's being tested. And you have a sort of VIM and VIGAR about, it's so cool. Your passion's infectious. That's why I love your YouTube channel. But then I look over to kind of M theory, string theory, hardcore theoretician side of stuff, and it just seems like, I can say this because I'm not a physicist and I'm not getting even trouble, but it just seems like this weird boring groundhog day circle jerk of people not really making legitimate progress in any one direction from what I know.

2:02:49It's incredibly sort of tribal and quite politically kind of driven, oddly the people that are trying to sort of transcend or helping us transcend humanity, some of the ones that are the most captured by it. It just must be of all of the different areas that you could have found yourself in physics. It seems like there's lots to do, lots of new territory in ground to cover, very much are kind of like Captain Cook, New World's sort of let's go find some cool stuff out over here. Mentality as opposed to, yeah, this very slow moving quicksand that may be going backward, maybe going in the wrong direction, who knows on the like hardcore theoretician side.

2:03:32Yeah, I think academia is littered with many issues, many problems. It is by far away from a perfect idyllic system. I mean, when I was a kid, I actually did wanna be a professor, I thought about that. I never thought I'd be doing it to be honest. I never thought I'd get to that point. It seemed like you'd have to be like some kind of super junior or something to become a professor. But it seemed idyllic in that I imagine you just sat in your office and thought about the universe all day. And that's not really, sometimes you get moments to do that. But most of the job is not doing that. And people don't act with pure intents.

2:04:10People aren't all driven just by this pure scientific ideology. Like any industry, like any corporation, any field, there's personalities, there's cultures, there's people trying to play politics, trying to protect their little area and try to shoot down your little area. And that's distressed. A lot of academics do become disenfranchised and disillusioned with the whole game and and eventually leave the field and go on to become much more successful, working in a hedge fund company or finance, especially my colleagues that's very popular to basically just cash out. You call these math skills, why not use it to make bank, right?

2:04:50Because it's actually not that hard to do so. Finding all of these stupid planets. We can't make money off the back of those. Right. And I think, and I know very clearly there was a colleague of mine. He was brilliant and he felt this way. He said, like I wrote this package that everybody, the software packages, statistical packages that everybody in the whole community is pretty much using at this point, they've been cited thousands of times. There were entire conferences organized about his paper and about his work. And yet he could not navigate his way to a successful faculty job despite that, because people would say, well, you're just a software engineer in the field.

2:05:29or you're not real, you're not a real astronomer. And so there was that kind of pretentiousness of, you're not doing the kind of hardcore, maybe string theory, M theory, pen and paper stuff that maybe people might imagine when they think about a physicist looking like. And so those stereotypes have been problematic if restricted him enormously, of course. And he said, I just don't know what I'm supposed to aim for. I just wanna know what is it that I am supposed to do? Is it supposed to get citations? because I've got that. Is it because I'm supposed to be invited to talks? Because I get, so what am I supposed to do?

2:06:04And he was so frustrated, and eventually said, I'm done with this. I'm just left the field. And I think that's a different example, but software engineers, we are now trying to promote that actually. So the Simon's Foundation, which is down the road from us here, they're now starting up faculty jobs that are supported privately, just in software engineering, in astronomy, and other sciences as well. But they're really putting money to support these types of positions because they are so important. But even in my own little world of exo -moons, which is like the most niche thing in the world, you could imagine working on.

2:06:40I spend not all my time working on that, but I spend a significant fraction of my time working on that. But I don't want to do one thing. But when in that little world, there's probably only a few dozen of us on the planet who are thinking about exos means in a professional setting. And even within that little world, it's been not always the most, you know, pleasant experience in mixed colleagues because I think sometimes when it is a very small field, people do get very competitive. And if you're a, if it is a small pond, the temptation is to have that we just have to have one big fish. And where if it's a big pond, people maybe play a little a little bit more easily together or maybe like a large collaboration tries to become the big fish that takes over.

2:07:19But certainly through an niche field, and I think string theory and M theory have become, there's not many students we recruit now that are interested in work on that topic. But I think whenever you have a field that does become fairly insular, politics and the darker side of human behavior doesn't inevitably play out. And that happens in all fields. So it's not, I don't think it's necessarily isolated to theoretical physics, end theory, string theory. I think it happens in every aspect of science to just different degrees. And it is something which I hate. And I always try to avoid as much as I can.

2:07:58But even doing stuff like this, doing YouTube videos, podcasts, even that will create friction, right? Because people will be like, well, you're not doing real science. You know, you should be just, all your time should be dedicated to doing pure research, which obviously I disagree with. Like, if we don't talk about our research, we don't talk about the universe and get people excited about what's out there, what the hell is the point of this? Like, no, we're not training the next generation, we're not inspiring anyone, we're not, you know, ultimately bringing in funding to support our activities.

2:08:28So, and also it makes me a better scientist when I do this kind of work. But everything you do, there's always going to be a site, there's going to be that site that wants to downplay it and poor cold water on it. But I think just having a thick skin is probably the best advice I can give anyway. If you just get to a point where you just don't care, which is kind of the fact that you do what I've got to, then you just like, I know, this is the right thing for me. I'm just gonna do it. I know this is the right thing. And I think that's hard to get through. But when this politics playing out, that's the only advice I have.

2:08:58It's just try to like, keep your head down and just push through those headwinds. Yeah, it's strange that Puritans and politics exist even in physics, which we would hope are kind of above that or outside of that maybe in a different dimension. I did want to ask about how your YouTube channel, which is maybe million subscribers, all of the different things that you do, how balancing that with tenure track, I mean, have you got people that just purposefully take your modules and your courses because they love your YouTube channel and they want to be near Professor Kipping. How have those streams crossed over?

2:09:36Has it helped you get access to really phenomenal grad students to come into your lab? It must be a big usefulness there? It has been. When I make the videos, I always make them assuming nobody watches them. At least nobody I know watches them. That's for sure. I make them in a sense that I them to be high quality and the highest product I can, the best I can do with it. But I always assume that no one in New York watches it. And so it's always very strange to me when someone talks to me about it. Bumps into you, sometimes it's in the street, someone will ask you about it, not that often, I'm not super famous for anything.

2:10:16But and especially when I go to an astronomy conference and other astronomers say I watch to a video. And that's always a surprise because I was like, well, I almost feel bad because that video wasn't meant for you. It's cool that you watched my video, but that video was not meant for a professional astronomer. Not as I think long in the video, but you were just not the audience that I was like gearing that to when I made that video. So I almost feel like bad when they watch my videos, that they see a presentation style as a speaker, which is not reflective of how I would give a colloquium or a seminar or something in a way.

2:10:52But it has been useful and we've been able to one of the one of the major ways it's been useful is actually through donations to my team. So we have a research account called the Cool Wars Lab Research Account here at Columbia University and people donate anywhere from five bucks a month up to I think our maximum is 500 bucks a month, we have a few of those. Where can people know? So if they want to donate to your lab, why should they go? Yeah, it's coolwildslab .com is the website, and then there's a link called support in there. You can hit. So if you head over to there, you can support us. And the amazing thing is that you are, you know, this isn't money that I get.

2:11:30So this isn't like a Patreon where you get to pay through it. Gold and throne in your office, some miracle, and we're like, no, no, I don't see any of this money directly. It all just supports, it all just supports research. That's it. So we're supporting like paying for the students, stipends to keep them to hire them to recruit them. We're paying for super computer time, cluster time for disk space, publication costs, travel cost to conferences. We're supporting bridge program students. So we're doing all this activity with it. And especially it's been great because it's allowed us to get off this academic wheel that we've sort of been alluding to of how do you pursue your research passions?

2:12:09One of my research passions is, as we talked about, searching for life in the universe. But believe it or not, that's very hard to find funding for, especially for intelligent life in the universe. It's still kind of got a giggle factor aspect a little bit to it. And it's pretty hard to persuade NASA or the National Science Foundation to hand over much money to do research in that area. But it's, I think, one of the most interesting questions we can do, and many people agree. And so the funding we get from the public has allowed us to basically pursue the questions that we think are the most interesting rather than the questions which we know are most likely to get funded.

2:12:48Right. So that's typically when I'm writing a grant, that's typically how we have to write grants. You typically have to write the grant to be, this isn't what I'm interested in. This isn't even particularly interesting to anybody, but I know this is the boring science that they will likely fund. And it's usually boring because it's low risk. It's something that you just know you can do. And anyone could frankly do it, who's a professional astronomer, is just arduous. And it's not even, frankly half the time, particularly that interesting half the stuff that you get done with these grants. But you know it's kind of a guaranteed slam dunk hit that you will have a guaranteed science product at the end of this work.

2:13:27Whereas high risk work is by nature, you don't know where it's going to go, what the product's going to be, but you're asking much bolder and ambitious questions. And if we just always cut short and just go for the simplest stuff with the guaranteed results, we're never going to really advance the field and advance our ambitions in space. So I've been very proud and honored to have those donations to support our work, and that's been a big influence. And of course, it has been useful for recruitment to some extent as well. Yeah. What is this satellite time, this observation time that I know that you just got a big allowance for.

2:14:08I saw your video about it. Yeah, so it's a telescope time on the James Webb Space Telescope. So James Webb is the success of you. This is like playing Glass -Tamboury, right? Main stage. Oh, yeah. This is this is the pyramid stage. Yeah, this is big. So the James Webb Space Telescope, six and a half meter telescope is an infrared telescope. It was launched a few years ago now, it's in its second year of science operations. And we proposed for each of the previous two years, we had proposed as well to search an exo -plata for an exo -moon. We had previously claimed evidence, tentative evidence of exo -moon in two other systems.

2:14:48But we hadn't really got to the point where the evidence was overwhelming. And to do that, you really want something with a precision of the best Husky, which is James Webb. So we put in this pitch, but the problem is, I mean, there's, as I said, there's hardly anyone working on XM. So it's very unlikely this gets peer reviewed that the peer reviewer is going to be someone who's particularly fond of XM. There's not right. Okay. So there's a little bit of politics there in terms of like getting selected time. And so I have to say we were very pessimistic. We put in, And we had this planet that I actually discovered.

2:15:21I discovered this planet myself in 2016. It's called Kepler 167E. And I knew it was the perfect planet to look for an XMN, just coincidence, I guess, that I found out. But the planet is as similar to Jupiter as you could possibly want. Has the same temperature as Jupiter, the same mass within 1 %, the same radius, the same orbital eccentricity, everything about it is just Jupiter, Jupiter, Jupiter. So if this planet is like Jupiter, it should have the same kind of moons that Jupiter has, and we could prove that JWST could detect those moons. So this was why it was so exciting. It was the only system this was true of.

2:16:02So we actually went through 5 ,000 or 5 ,000 exoplanets that had been discovered to date, and we calculated for each one of them, what's the biggest moon it could have? Could JWST detect that? And there was only about half a dozen or a dozen of planets that came out as potentially doable. And this one was by far the best, by far the best of the top. But only transits, which is the event we use when it eclipses its star, it only does that every three years. So if we didn't get the telescope time in the next cycle, which is in October, we would have to wait three more years to 2027 just to have another shot at doing this again.

2:16:40And, did you see, you know, I hope it's still around, it should still be around 27, but you never know, like it's been hit by a meteor already once and damaged one of the mirrors, so we just don't know for sure. We want to see this thing happen over and over again to get short of evidence of its existence. So we were surprised but very excited that they granted us a huge wallop of telescope time. We asked for 60 hours of telescope time, and they gave us it. And we need 60 hours because this planet is so far from its star that it takes a long time for it to eclipse over its star. Remember that the lunar eclipse, the total eclipse we had when the moon passed in front of the sun that we had in America just recently, that's a four minute transit basically.

2:17:24Whereas the event we're looking at lasts for about 20 hours, I think. So it's, you know, it's a 20 hour eclipse that you have to stare at. And then there's, you want to have like 20 hours either side to sort of calibrate your data and look for the XO moons. What would happen if you found XO moons? I think the hope is that this is just the start of what happened in the field of XO Plants. So, go back 25 years ago where, at 1995, a little bit for 30 years ago, you have the first XO Plant being discovered, 51 Peg Cb. Before that, hardly anyone was work on XO Plants. It was considered fringe. It was considered like looking for alien life, and not a serious science.

2:18:03And despite that, most people thought, well, they should be out there. It seems obvious that planets should be out there, but it's intrinsically risky to try and claim you're the first person in anything, in a scientific discipline. So I think, with XA moons, I see an analogy that we will hopefully be able to make the first one. And now, cycle forward 25, 30 years after that first discovery, you have 5 ,000 plus exoplanets being used, being found now exoplanets represent probably about a quarter of all astronomy funding, depending on how you count it. But about a quarter of all astronomers and astronomy funding goes to exoplanetary science.

2:18:4230 years ago that was zero. So there's been a blossoming of an entire field and it's not just for the sake of a field. We've learnt so much about, we've completely revolutionized our understanding of planetary systems. We thought the solar system was the way it happened everywhere. We thought that was it and that's totally wrong. That's totally wrong. The solar system is, if anything, like a weirdo on the block. It is just profoundly altered our world view of who we are in the universe. And it has now opened up the door to potentially detecting life in the next 10 years or so using these next generations of telescopes.

2:19:17Examoons will surely offer up so many surprises that we can't even anticipate yet. They may be seats for life in their own right, as we've already talked about. They may influence the possibility of life on the planets they orbit, the moon and the earth remember, there's a connection there as to how that could be interacting with one another. And then finally, if we want to eventually take a photo, which I think we do, we want to take a photo of an Earth -like planet one day, we have to know about the moons around them. Because if I take a photo of a pale blue dot of light, a distant image, I will be able to resolve the planet from the star with these impressive next generations of telescopes we're planning, but I will not be able to resolve the moon from the Earth.

2:20:02They will be too close together for the telescope to resolve. So that pale blue dot of light will actually be a pale blue gray blob of light. It will be the mixture of light from the moon and the Earth. And when we look at that light, if we don't understand there's a moon in there. We're going to completely misinterpret what the hell of that light even means. If you don't recognize that there's a moon in there, in fact, it could even cause us to think we've detected life when we haven't. So I think this is a very, very important question to figure out, both for scientific goals, but also for our goals of trying to understand our uniqueness and origins in the in the universe.

2:20:44us. How exciting, man. David, I love your stuff. I love your YouTube channel. Let's bring this one into land. Where should people go? They want to check out everything that you do and follow you and support. Yeah, so you head to my YouTube channel. That's called the Cool World's Lab at Cool World's Lab and you can find that channel over there. We also have the Cool World's podcast, which we started over the last year. Again, just grab that on YouTube or iTunes wherever you are. And finally, you can also just check Check out my Twitter handle, David underscore Kipping and head to my website, koowardslab .com, if you want to learn more.

2:21:16Hell yeah, David, I really appreciate you. Thank you. Thank you. And Doug, here we have the Lemo Emu in its natural habitat, helping people customize their core insurance and save hundreds with liberty mutual. Fascinating, it's accompanied by his natural ally, Doug. Uh, Lemoo, is that guy with the binoculars watching us? Cut the camera! They see us! Only pay for what you need at LibertyMutual .com Liberty Liberty Liberty Liberty Liberty Savings very underwritten by LibertyMutual Insurance Company and Affiliates Excludes Massachusetts