Joe Rogan Experience #2363 - David Kipping

1. 0:00 – 3:49

   James Webb’s first big surprises: early galaxies and impossible quasars

   1. NANarrator0:00

      (drumbeats) Joe Rogan podcast, check it out.

   2. JRJoe Rogan0:04

      The Joe Rogan Experience.

   3. DKDavid Kipping0:06

      Train by day, Joe Rogan podcast by night, all day. (instrumental music plays) And we're up.

   4. JRJoe Rogan0:13

      What's up, man? How are you?

   5. DKDavid Kipping0:14

      It's good. Yeah.

   6. JRJoe Rogan0:14

      Pleasure to meet you, sir.

   7. DKDavid Kipping0:15

      Pleasure to be here. Thanks, Joe.

   8. JRJoe Rogan0:16

      I really enjoy your content online. It's been really fascinating, so I've been doing a deep dive into a lot of your videos over the last few days and-

   9. DKDavid Kipping0:23

      Yeah.

   10. JRJoe Rogan0:23

       ... enjoying the hell out of it, and, uh, particularly enjoying... Uh, I wanted to talk to you about so many different things, but one of the most pressing things, one of the reasons why I wanted to bring you in, 'cause you are very knowledgeable in all things space, is the James Webb Telescope, and, uh, all the different stuff that they've been finding, particularly about these galaxies that were formed very shortly after the... not shortly, you know-

   11. DKDavid Kipping0:47

       Yeah.

   12. JRJoe Rogan0:47

       ... not within our, our lifetime shortly, but-

   13. DKDavid Kipping0:49

       Right.

   14. JRJoe Rogan0:49

       ... cosmologically shortly after the Big Bang, that, uh, it seems like we have to figure out why these things are forming. Is the universe older? There's all this different kind of speculation. Maybe the Big Bang is not 13 point whatever billion years old, but maybe 22, 24. Like, what, what is your take on all this?

   15. DKDavid Kipping1:11

       Yeah. The, the James Webb Space- Space Telescope is such an incredible instrument. The data has just blown us away. You know, when you build this thing and you look at it un- unfolding in space, you think there's so many ways it could go wrong, that we all were just like... You know, there's, I think there's 215 moving parts or something had to unfold. So, you know, just the fact that it-

   16. JRJoe Rogan1:29

       In space. (laughs)

   17. DKDavid Kipping1:30

       Yeah. (laughs) The fact it just all worked was just remarkable.

   18. JRJoe Rogan1:34

       Right.

   19. DKDavid Kipping1:34

       And then when we got those first images, they just kind of blew us away as well, 'cause they, we had sort of these engineering expectations of what it would do, but the data was just even better than that. So when it, you know... Of course, the first thing you want to do is point it to the most distant part of the universe and see what's out there-

   20. JRJoe Rogan1:48

       (laughs)

   21. DKDavid Kipping1:48

       ... in those darkest patches. And so when it did that, yeah, it started finding a couple of things. It started finding quasars, which are kind of the, uh, the center of these very active gala- galaxies. These are super massive black holes that have loads of crap falling in, and they're spewing out all this energy. They're kind of feeding super massive black holes. And so we started detecting those way earlier than we thought the universe should be able to build them. Because to make a super massive black hole, I mean, these things are like a, a hundred million solar masses. Imagine that, a hundred million suns-

   22. JRJoe Rogan2:18

       Pew.

   23. DKDavid Kipping2:19

       ... have c- have not only been born, but died, gone through their entire life cycle, died, collapsed into a black hole, and then those black holes have presumably somehow merged together into this super behemoth of this hundred million solar mass thing. So we're finding those just, you know, 300 million years after the Big Bang. And that, that was like, "Hold on. That, that doesn't make any sense. Like, how, how can this be?" And similarly, with the, uh, with the galaxies, we were seeing these images. These galaxies, and you can date roughly how old they should be based off the red shift. So, the l- you know, the universe is expanding, so therefore, if something is very far away from us and the universe is expanding, its light gets stretched more and more and more as it journeys over space. And so we can use that red shift to kind of date how old these things are. When we use those dates, we look at these images, again, they seem suspiciously too, too old. You know, you really shouldn't be able to form these things that, that early on in the universe. And so that kind of puzzled us. Um, I think for the galaxy thing, there was a bit of a resolution there. One of the, uh, resolutions is that we probably, um, miscalculated how, how easy it is to form these galaxies in the first place. So we had these models for galaxy formation. We had these models for how stars should form, how quickly they should live. But it was all essentially calibrated on what we see around us, like right here in this part of the universe, in the local universe. And then we kind of realized that those same models probably need to be tweaked if you're going to apply them to the early universe, where the density is so much higher, the, the gas temperature is much hotter. Everything's just, you know, completely different in the early universe.

2. 3:49 – 6:07

   Eddington limit, black-hole growth, and why rewriting cosmic age is unlikely

   1. DKDavid Kipping3:49

      So when you kind of make those corrections, it actually looks like maybe it's actually possible to make those galaxies earlier than we thought. So I think the galaxy problem is a bit easier to explain. I think the quasar problem, to me, is more interesting. How do you get those super massive black holes so early? Um, there's a certain kind of maximum rate you can feed these things called the Eddington limit, and that's sort of, you throw mass into a black hole, and so much energy is going in, some of it spews back out. And the energy which spews back out stops other stuff coming in. Right? So there's a maximum limit. You can't build a black hole faster, in principle, than this Eddington limit. And yet, when you do the calculation, these black holes must have been fed what we call Super-Eddington, so faster than Eddington. So something's wrong with our models, right? Either, e- either we've got the universe age wrong, which I think is possible, but I would say that's probably a much less likely solution, or we've got the astrophysics wrong.

   2. JRJoe Rogan4:44

      Why do you think that the universe's age is a less likely solution?

   3. DKDavid Kipping4:48

      Because we've got this, this... You know, like in particle physics, you've got the standard model, which includes like all the particles and the electron, the baryons, all this kind of stuff. And in cosmology, we have a similar kind of model. It's called Lambda-CDM. And so the Lambda stands for dark energy and the CDM is cold dark matter. So this is our standard model, and we have used it to explain so much stuff in the universe, Joe. I mean, we're talking about the cosmic microwave background, um, oscillations in the sky, like these baryonic acoustic oscillations, the stretching of the universe, Cepheids. You can use it to explain so much stuff, and it works beautifully. I mean, it works down to, like, the 0.01% level. So if you say the universe age is wrong, you have to give that up. So maybe it is, maybe it is wrong, but if you give that up, you have to come up with a radical new idea which can now explain all of this stuff at that same level of precision. The much more likely answer, in my book, is that astrophysics, like the, you know, gas swirling around, the plasma colliding with each other, that's just more complicated, in my mind, than the, than the actual model of just the simple expansion of the universe, which actually is a fairly simple geometric model.

   4. JRJoe Rogan5:58

      Fairly simple in that you can use whatever methods that we're using currently to measure everything that's out there and it makes sense.

   5. DKDavid Kipping6:07

      Yeah, yeah.

3. 6:07 – 8:45

   How new telescopes keep breaking models: the Hubble Tension

   1. JRJoe Rogan6:07

      But-If we're let- if we're using something like the James Webb Telescope, so we're getting a much deeper view of the universe, how limited is the James Webb in comparison to the James Webb 2.0, 3 point-

   2. DKDavid Kipping6:21

      Yeah.

   3. JRJoe Rogan6:22

      Like, are we going to have to continually revamp what our, uh, our understanding of this process is?

   4. DKDavid Kipping6:29

      Yes, we will. And that's, that's, what, that's-

   5. JRJoe Rogan6:31

      That's exciting.

   6. DKDavid Kipping6:31

      ... what I love, right?

   7. JRJoe Rogan6:32

      Right.

   8. DKDavid Kipping6:32

      That's what scientists love. Ev- every time we've built a telescope that is, you know, uh, 10 times more precise than the last thing, every time we've done that, we have been surprised. And so these early galaxies are a good example. Um, the cosmological experiments that are going on now, one of the big, like, surprises is this thing called the Hubble Tension. Have you heard of that, Hubble Tension?

   9. JRJoe Rogan6:50

      No.

   10. DKDavid Kipping6:50

       So Hubble Tension is measuring the expansion rate of the universe, how fast are things flying apart. And you can do it two ways. You can use the, uh, cosmic microwave background, so that's the earliest radiation that we can detect, this is that stuff that's about three Kelvin warm you can detect in the microwave, and this is the light which has traveled basically when the universe was 380,000 years old. It's that light, and we see it in all directions. That's how we know the Big Bang kind of didn't happen in one place. It happened everywhere 'cause you just see this light coming in from all directions. And from studying that, that radiation, you can, you can kind of get a model of the universe, and then you can calculate using this model how fast should the universe be expanding today if I run the clock forward, and you get a number. And then if you do that same experiment but locally, you actually measure the stars, you measure the supernovae around us, these pulsating stars, and you actually measure how fast this stuff is expanding, you get a different number. They don't line up. And so this is really weird. So somehow something's wrong, right? Either our measurements of the local universe must be wrong in some way, or this model that we're using to calculate the whole history of the universe, something is wrong with that model. So this is a very famous growing problem in cosmology. It's now what we call a five-sigma level, so that means the chance of this being random is just, like, zero essentially. It's just, this, this is a real effect, and now we just have to figure out who's wrong. Is it the observers or is it the theorists?

   11. JRJoe Rogan8:16

       Wow.

   12. DKDavid Kipping8:17

       It's an exciting time.

   13. JRJoe Rogan8:17

       Where do you, where do you fall on this?

   14. DKDavid Kipping8:19

       (sighs) Y- yeah, it's hard. I'm, I go, I swing between both ways, (laughs) you know? I would talk to my cosmology colleagues, and they'll, you know, depending on who I talk to, they'll convince me either way. Um, so I think the-

   15. JRJoe Rogan8:33

       That's disturbing that people are convinced. (laughs)

   16. DKDavid Kipping8:37

       (laughs) You know, if it's, if- Right.

   17. JRJoe Rogan8:38

       ... these new telescopes keep showing us this new puzzle-

   18. DKDavid Kipping8:41

       Yeah.

   19. JRJoe Rogan8:42

       ... it's kind of, uh, it always bothers me when someone is, like, rigidly convinced.

4. 8:45 – 12:44

   Scientific bias, humility, and the exomoon false alarm story

   1. DKDavid Kipping8:45

      Ev- everyone has a certain pet theory, right-

   2. JRJoe Rogan8:48

      Bias.

   3. DKDavid Kipping8:48

      ... ... they're trying to push.

   4. JRJoe Rogan8:48

      Yeah.

   5. DKDavid Kipping8:49

      Every, I mean, we all have biases, right?

   6. JRJoe Rogan8:50

      Of course.

   7. DKDavid Kipping8:50

      Yeah. So-

   8. JRJoe Rogan8:51

      Human beings.

   9. DKDavid Kipping8:52

      Yeah. I mean, if you've spent ... It's hard, right? If you've spent 20 years of your life, your, you know, most of your academic career-

   10. JRJoe Rogan8:57

       Yeah.

   11. DKDavid Kipping8:57

       ... studying this one thing, it's really hard to turn around and say, "You know what? I screwed up," right? "Those 20 years of measurements, they were all wrong, and I have to eat humble pie." That's not easy, but it has happened in some cases. One of my fave- favorite stories about this is, uh, the fir- the first exoplanet that was ever claimed, a planet around another star, uh, one of the first ones, it was, um, wrong. So it was, it was a, a pulsar that had a planet, a supposed planet around it on a six-month orbital period, so exactly half the Earth's orbital period around the sun. And they saw this signal in their data, this, this pulsating star was doing something weird, and they figured out there was a six-month period around it. So the, the dude published this paper, uh, Matthew Bailes, brilliant astronomer, and he realized later on it was wrong. And instead of it being a real planet, he hadn't quite corrected the orbital eccentricity of the Earth. So the Earth is not in a circular orbit. Its eccentricity is .0167. It's a tiny number. But that number hadn't been accounted for in the calculation. And so he had to stand up in front of hundreds of astronomers at this famous IAU meeting, and he admitted he was wrong, and he got a standing ovation for doing that.

   12. JRJoe Rogan10:06

       Oh, good for him. Yeah.

   13. DKDavid Kipping10:07

       It's awesome. It's one of the few times I've heard of someone doing that, and I think it's dope. I think we need to encourage people to concede that.

   14. JRJoe Rogan10:13

       Well, with something that's so massive and is such a puzzle, this is just bound to happen-

   15. DKDavid Kipping10:18

       Yeah.

   16. JRJoe Rogan10:19

       ... if you get people that are rigidly attached to their belief systems, in, in terms of, like, a very limited understanding of a fantastic thing that is almost beyond imagination when you think about the-

   17. DKDavid Kipping10:29

       Yeah.

   18. JRJoe Rogan10:30

       ... just the sheer size of the universe and the age of the universe. I mean, when we're talking about aging, and we say 13 billion or 22 billion, th- those numbers don't even register in your mind. They're not real.

   19. DKDavid Kipping10:42

       Yeah.

   20. JRJoe Rogan10:42

       You know what I mean? It's like, that you see a one and a three, and you kinda get it, but you don't get it. There's no way.

   21. DKDavid Kipping10:48

       You, you can't intuit it, yeah, yeah.

   22. JRJoe Rogan10:49

       No, it's not possible for our puny little minds to imagine 13-plus billion years. It's just too crazy. So if you're rigid with that, like, God, man.

   23. DKDavid Kipping11:02

       Yeah.

   24. JRJoe Rogan11:02

       Like ...

   25. DKDavid Kipping11:03

       I mean, pa- part of the journey in being a scientist is, is knowing what your own biases are. And I, I remember, you know, one of my threads in my career has been trying to look for exomoons, moons around these exoplanets, which would be a first if we got them. So that's a, you know, it's a big deal, right? You know if I succeed at this, there could be like, you know, golden prizes, awards ceremonies. Like, you, you kinda get that glimmer in your eye, like, "Oh, man, this could, like, I could be memorialized for this success."

   26. JRJoe Rogan11:27

       (laughs)

   27. DKDavid Kipping11:27

       And so that's, that's alluring, right? That's tempting.

   28. JRJoe Rogan11:30

       Mm-hmm.

   29. DKDavid Kipping11:30

       It's, it's kind of the same temptation as fame. And I remember once we had this signal, uh, it was Kepler-90, uh, no PHTB was the name of the planet, and we had this signal, and it kinda looked like just what we expect for an exomoon. I remember I was so excited, I had to, I was at Harvard at the time, I had to walk out the building, I had to go to a park bench, and I had to just take, like, deep breaths.

   30. JRJoe Rogan11:51

       (laughs)
5. 12:44 – 16:02

   Exoplanet diversity: hot Jupiters, mini-Neptunes, and how unusual our Solar System may be

   1. JRJoe Rogan12:44

      (sighs) What do we know about the consistency of solar systems and galaxies being formed? We know they vary in size. Do we understand why, and we understand what causes them to form in the first place?

   2. DKDavid Kipping13:01

      Yeah. We're still learning that. The... You know, we had this picture before we started finding exoplanets that everything would just be like the Solar System. You know, you have these, these eight planets, circular orbits. You have the rocky planets on the inside, the gas giants on the outside. And we came up with this really elegant theory, this kind of nebula theory, to try and explain that. And did a great job, explained everything. But then as soon as we started finding exoplanets, I mean, one of the first type of exoplanets we found were these hot Jupiters. These are Jupiter-sized planets which are about 20 times closer to their star than Mercury is around the sun. And when those were first announced, nobody believed them. People were like, "You can't, you can't get a Jupiter there. Like, Jupiter's supposed to be 5 AU. How do you get it parked on, almost onto the surface of the star? It doesn't make any sense." No, none of the planet formation models could explain that. And it took until we found about 10 of them in a row that people started slowly changing their minds, and the proof of the pudding was when one of them eclipsed its star. So, one of them actually passed right in front of the star-

   3. JRJoe Rogan13:55

      Oh.

   4. DKDavid Kipping13:55

      ... right at the moment it was supposed to, and we saw an eclipse. And when that happened, everyone was like, "All right, it... This is, this is real." But then we had to figure out how the hell do you do that. So there was a long, it was a long skeptical curve to get to that point. And now we think the way to make those things is there's probably Jupiters on the outside of the Solar System. They come too close to each other, their gravitation... They're like kind of wrestling almost, they kind of excite each other. One of them gets kicked out in a random direction and it can get flung into a highly eccentric orbit. And a highly eccentric orbit over time will circularize. So it doesn't wanna stay on a, a concentric orbit. It wants to turn into a circle through the tidal interactions with the star. So these things probably circularize really close onto their stars. But this is unusual, only happens about 1% of star systems we see this. But it's an example of how diverse things are. Um, another example is mini Neptunes. You ever heard of those planets?

   5. JRJoe Rogan14:44

      No.

   6. DKDavid Kipping14:45

      So mini Neptunes are these planets which are in between the size of the Earth and Neptune. Neptune's about four times bigger than the Earth, so these things are about twice the size of the Earth. We don't have anything like that in the Solar System, so we don't know what it is. Is it a big rock? Is it like a super-Earth, a mega-Earth? Or is it a scaled-down version of Neptune? Is it like an ocean world, maybe, of some kind? And turns out that planet is the most common type of planet in the universe, as far as we can tell.

   7. JRJoe Rogan15:12

      Whoa.

   8. DKDavid Kipping15:12

      And we don't have one.

   9. JRJoe Rogan15:14

      Wow.

   10. DKDavid Kipping15:15

       So that's kind of weird, right? I mean, it seems like there's so many aspects of our Solar System that are unusual. Even having a Jupiter, only 10% of stars have a Jupiter, as far as we can tell.

   11. JRJoe Rogan15:25

       10% of how many stars that have been observed?

   12. DKDavid Kipping15:28

       Oh, at this point? I mean, we've observed hundreds of thousands of stars, um, and we know of about 6,000 exoplanets. So of that population, you correct for the success, you correct for the ones you've missed. Even so, I mean, these Jupiters are the easiest ones to find, right? They're the big boys, they're easy, they wobble the star a ton, so they're pretty easy to spot. Um, so we're pretty confident that sun-like stars, it's, it's kind of not typical for them to have these Jupiter-sized planets, and we've got two of them.

   13. JRJoe Rogan15:53

       Hmm.

   14. DKDavid Kipping15:53

       So that seems interesting, right?

   15. JRJoe Rogan15:54

       Yeah.

   16. DKDavid Kipping15:55

       To our, to our own origin in this Solar System. And suddenly having eight planets? That's pretty unusual. We don't see many systems with that many planets packed together.

6. 16:02 – 19:01

   Binary stars and JWST direct imaging: a candidate planet at Alpha Centauri A

   1. JRJoe Rogan16:02

      How many solar systems are binary solar systems, as opposed to having a single star?

   2. DKDavid Kipping16:08

      Yeah. Yeah, about half of all stars live in binary systems.

   3. JRJoe Rogan16:12

      Really?

   4. DKDavid Kipping16:12

      It's very common. So actually, Alpha Centauri AB, that's the nearest star system to us, and it's actually a trinary. There's Alpha AB that go around each other really close, and then there's Proxima Centauri, which is on the outside. And actually, just this morning, Joe, just this morning, there was an announcement of a giant planet around Alpha Cen A. It's a candidate. We don't know if it's confirmed yet, but it's, it's kind of in the habitable zone, so the distance where, in principle, you could have liquid water on the surface of a rocky planet.

   5. JRJoe Rogan16:43

      So it is a candidate f- for a planet? Or like, it, it has been-

   6. DKDavid Kipping16:48

      Yes.

   7. JRJoe Rogan16:48

      ... it, so it hasn't been completely confirmed as a planet?

   8. DKDavid Kipping16:49

      James Webb just spotted it.

   9. JRJoe Rogan16:50

      Oh.

   10. DKDavid Kipping16:50

       James Webb spotted it just, just the, just come out today. So there's three photos that James Webb took. Maybe they'll be in this article somewhere. He took three images and in one of those images, it captures an actual photo of the planet. You can see the planet in direct light.

   11. JRJoe Rogan17:05

       Whoa.

   12. DKDavid Kipping17:05

       That's how powerful James Webb is.

   13. JRJoe Rogan17:08

       Let me see that.

   14. DKDavid Kipping17:08

       And it's a nearby star, so it's easy to image. Yeah, right here, so... That S1, that's the planet you're looking at.

   15. JRJoe Rogan17:16

       Wow.

   16. DKDavid Kipping17:18

       So you can see you have to block out the star in the middle, 'cause the star is like a billion times brighter than the planet is, so-

   17. JRJoe Rogan17:22

       (laughs)

   18. DKDavid Kipping17:23

       ... you have to suppress it with all this advanced coronagraph technology that James Webb has. But when you do that and you zoom right in, you see this little planet there? That's, uh, it's probably about the same size as Saturn. It's probably a big boy.

   19. JRJoe Rogan17:33

       I love how they went with a real clickbaity headline with Avatar planet, the other, the other article that you pulled up. What was it saying?

   20. DKDavid Kipping17:40

       I was quot- I was quoting that one, so I know-

   21. JRJoe Rogan17:42

       Planet from the Avatar movies may exist in real life (laughs) . Like, shut up. You're just trying to get people to click on that.

   22. DKDavid Kipping17:47

       (laughs)

   23. JRJoe Rogan17:47

       It's a f- It's kinda weird that they have to do that.

   24. DKDavid Kipping17:50

       (laughs) .

   25. JRJoe Rogan17:50

       But like, this is the world we're living in now. Everyone has such a short attention span.

   26. DKDavid Kipping17:53

       Right.

   27. JRJoe Rogan17:53

       You're fuddling through your Google feed like, "What's new?"

   28. DKDavid Kipping17:56

       (laughs) Yeah, it's gotta connect to something pop culture. Otherwise, people are like, "Ugh."

   29. JRJoe Rogan17:59

       Yeah, it's gotta get you somehow, like some, there's some editor.

   30. DKDavid Kipping18:03

       It's probably more like, you know, um, The Three-Body Problem, the-
7. 19:01 – 21:45

   Bode’s Law, asteroid belts, and the idea that stability sets planet spacing

   1. JRJoe Rogan19:01

      So do, uh, because they vary so much in the, the way these galaxies and the way these solar systems are constructed, do we know why they're constructed in the first place? Like, why, why do they form in that way? Like, why does Bode's Law work? Does it still work?

   2. DKDavid Kipping19:21

      It kinda works, but it makes some bad predictions.

   3. JRJoe Rogan19:23

      Can you explain Bode's Law to people?

   4. DKDavid Kipping19:24

      Yeah. So Bode's Law is essentially looking at the separation between the planets in the solar system. So Venus, for instance, well, uh, Mercury is about .4 AU, uh, Venus is .7, the Earth is one, and Mars is 1.5. So there seems to be a pattern, and I think it's, like, a fraction of 1.5 or something in terms of, like, take the last one and just multiply it by 1.5, and you roughly get to the next one.

   5. JRJoe Rogan19:43

      And is it dependent upon the mass of the planet?

   6. DKDavid Kipping19:45

      No.

   7. JRJoe Rogan19:46

      No?

   8. DKDavid Kipping19:46

      It's just, it's just purely their spacing. So it, it was, uh, yeah, it has some problems, though. It doesn't particularly work that well. It predicts there's a planet where the asteroid belt is, and obviously there isn't one there, but maybe you could argue something happened.

   9. JRJoe Rogan19:57

      That's probably why the asteroid belt's-

   10. DKDavid Kipping19:59

       But it-

   11. JRJoe Rogan19:59

       ... there, right? Doesn't that make sense?

   12. DKDavid Kipping20:00

       You could argue... Yeah.

   13. JRJoe Rogan20:00

       This episode is brought to you by Uber Eats. Summer is here, and you can now get almost anything you need for your sunny days delivered with Uber Eats. What do I mean by almost? Well, you can't get a well-groomered lawn delivered, but you can get chicken Parmesan delivered. A day in the sun? No. A bottle of rum? Yes. Uber Eats can definitely get you that for almost, almost anything delivered with Uber Eats. Order now. For alcohol, you must be legal drinking age. Please enjoy responsibly. Product availability varies by region. See app for details. (clears throat)

   14. DKDavid Kipping20:37

       Um, but then more, more problematically, people have tried to apply this to exoplanets. So you've got these multi-planet systems, and we know of, like, maybe three or four planets, and there's gaps. And so you can say, okay, let's use Bode's Law and predict, okay, there should be a planet right here. And then people have done the observations. They've, like, dialed in and put all the telescopes on and been like, "Where's that planet?" Sometimes they found the planets there, but usually not. It doesn't, it's not that predictive.

   15. JRJoe Rogan20:59

       How common are asteroid belts?

   16. DKDavid Kipping21:02

       We don't know. We can't detect asteroid belts.

   17. JRJoe Rogan21:04

       Right, that's hte question.

   18. DKDavid Kipping21:05

       They're too small. Yeah.

   19. JRJoe Rogan21:05

       So in these gaps where a planet should be, what if there was an asteroid belt in every one of them?

   20. DKDavid Kipping21:09

       Yeah.

   21. JRJoe Rogan21:09

       That would kind of change everything, wouldn't it?

   22. DKDavid Kipping21:10

       That'd be wild. I'd love that, yeah.

   23. JRJoe Rogan21:12

       Yeah.

   24. DKDavid Kipping21:12

       Then, then we'd be back to Bode's Law.

   25. JRJoe Rogan21:13

       Yeah.

   26. DKDavid Kipping21:14

       I mean, but Bode's Law, I guess it's, it's actually really a statement. There's a great, um, dynamicist at Princeton, Scott Tremaine, and he showed this, that if you just try to pack planets as close as you can, like, just shove them in like sardines into the solar system, some of them will become unstable and just get kicked out, and the ones that are left will follow Bode's Law. So it's, it's not so much a, um, a statement of like, you know, some deity is putting these planets at the right places. It's that if you just cram stuff in as much as you can, that's what you end up with. Like, you just can't cram planets any closer together.

8. 21:45 – 24:32

   How solar systems form—and the missing steps from dust to planets

   1. JRJoe Rogan21:45

      So what is our current belief system when it comes to the formation of solar systems?

   2. DKDavid Kipping21:51

      It appears to be very common. I mean, when we look at the data we have from the Kepler mission, NASA's extraordinary successful mission, it detected itself something like 4,000 exoplanets. And that tells us that on average, every single star has a planet. So as far as we can tell, this is, it, it's pretty hard for a star not to have planets. It's, like, par for the course for that to happen.

   3. JRJoe Rogan22:12

      Right.

   4. DKDavid Kipping22:12

      That was a big breakthrough. Um, the second thing is, as, as we kind of alluded to, there's a huge diversity in them. A natural story we normally describe for how they form is that there's some, you know, giant molecular cloud, we call it, so basically a giant cloud of hydrogen in space, stuff that could have been blown off from a previous supernova or something, or maybe even in the early universe, just primordial gas from the Big Bang, just this leftover hydrogen gas. And if there's be some areas where there'll be slightly higher density and some areas with a slightly lower density, just due to random fluctuations, and the higher densities will self-gravitate. Sorry, so gravity wants to make... It's like a greedy algorithm, wants to make everything get denser and denser and denser, super greedy. It's relentless. Gravity never stops. And that's why eventually we end up with black holes, right? 'Cause it just, it just refuses to lose, black hole. (laughs) Gravity just always wants to win the game. So eventually, these clouds collapse, and the thing that stops them from collapsing into a black hole is that you start getting fusion in the center, right? 'Cause the temperatures get so hot as you compress this gas that you basically make a star in the center. And the stuff that's left over on the outside, that disc of material, because the star kind of blasts out of its poles and kind of pummels all the gas from north and south, you end up with a disc of material. The centrifugal forces, like spinning a pizza ball, which kind of force it into a disc. And then from that disc, you start to coalesce. Again, just some areas are slightly denser, some areas are, are slightly less dense. And gravity again takes over and starts to collapse things together. So we have this story, but there's lots of parts of the story that we don't understand. So we know how to go, for instance, from, um, from pebbles, if you start off with pebbles, and imagine them kind of bouncing around, we can imagine sticking them into boulders. We kind of understand how that could happen, but we don't quite understand how to do some of the steps, like go all the way from dust, which presumably at one point it was just dust. How do you go from dust all the way up to pebbles all the way up to these boulders all the way up to planetesimals? That whole story, we don't understand. We get, we've got bits of it where we think we understand it, but the whole thing, we don't.

   5. JRJoe Rogan24:08

      Are there any working models or any theories?

   6. DKDavid Kipping24:10

      Yeah, this is a hugely, huge active area of research.

   7. JRJoe Rogan24:13

      Yeah.

   8. DKDavid Kipping24:13

      People are simulating dust on supercomputers, trying to stick it together, figure out what happened. Um, but it's chaotic. I mean, you've got...... trillions and trillions of particles of dust randomly moving around. And solving the equations to calculate their motion is one of the most challenging things ever. Maybe AI will help a big part with that.

9. 24:32 – 29:27

   Star sizes, red dwarfs, and hunting the first ‘pristine’ stars

   1. JRJoe Rogan24:32

      That would be interesting. Is it also a factor of the size of the sun? Like, our, our star is fairly small-

   2. DKDavid Kipping24:39

      Yeah.

   3. JRJoe Rogan24:39

      ... in terms of the, what we know about the universe. One of the most amazing videos that I, I tend to, to send people online is the video that shows-

   4. DKDavid Kipping24:48

      I know the one you mean.

   5. JRJoe Rogan24:49

      You know? Or, it shows-

   6. DKDavid Kipping24:50

      Yeah, yeah.

   7. JRJoe Rogan24:50

      ... Earth in comparison to our star-

   8. DKDavid Kipping24:52

      Yeah.

   9. JRJoe Rogan24:52

      And then, it shows our star in comparison to slightly larger stars. Then it goes on and on and on, 'til you get to, like, Betelgeuse and you get to some of these-

   10. DKDavid Kipping24:59

       It's wild. (laughs)

   11. JRJoe Rogan24:59

       (laughs) It just gets so crazy. Like-

   12. DKDavid Kipping25:01

       You're like, it's gotta stop at some point, but it keeps going. (laughs)

   13. JRJoe Rogan25:03

       Like, it's like a galaxy-sized star. (laughs) Like, what is that thing?

   14. DKDavid Kipping25:07

       Yeah. (laughs)

   15. JRJoe Rogan25:07

       It gets so nutty. It's so big.

   16. DKDavid Kipping25:09

       It's, it's strange, yeah. Yeah, it, I mean, our star is... I mean, those big stars, those are actually rare, right? So those are the giant stars of the universe, and most stars are not that big.

   17. JRJoe Rogan25:18

       What is the biggest one that we've found?

   18. DKDavid Kipping25:20

       Oh, I don't know the name. But yeah, I think you're talking about stars which are probably, uh, filling up to the orbit of Jupiter type size.

   19. JRJoe Rogan25:27

       (laughs) Yeah. So from here to Jupiter?

   20. DKDavid Kipping25:29

       Yeah.

   21. JRJoe Rogan25:29

       Oh my god. Just imagine a star from our sun that goes-

   22. DKDavid Kipping25:35

       (laughs)

   23. JRJoe Rogan25:35

       ... all the way out to Jupiter.

   24. DKDavid Kipping25:38

       It's nuts, yeah. (laughs)

   25. JRJoe Rogan25:40

       Wow!

   26. DKDavid Kipping25:40

       And these things are barely stars at that point. Like, if you actually, if you could zoom in a spaceship and look at the surface, it would, it would, it, the gravity would be so weak at that point, right? 'Cause the, the mass hasn't changed at the star. In fact, for anything, it's lost mass. So it's barely got enough gravity to hold that thing together. So the thing is, like, fluctuating. It's like a giant sheet that someone's waving up and down. So, that's why those stars have these wild flu- uh, fluctuations in, in, uh, brightness 'cause they're just kind of undulating on their surface.

   27. JRJoe Rogan26:09

       What is this one, Jamie? Is this the largest one?

   28. NANarrator26:11

       It's the biggest one, yeah.

   29. DKDavid Kipping26:12

       That's namely the biggest one, I guess, yeah.

   30. JRJoe Rogan26:13

       Stephenson 218. What is the little tiny one on the far left?
10. 29:27 – 35:17

    Ultimate telescopes: using the Sun as a gravitational lens & fast flyby probes

    1. DKDavid Kipping29:27

       Yeah. The ultimate, I mean, I love this idea of thinking about what would an alien do. How would an alien observe the Earth if they had, you know, unbounded technology, what would be the limit? And a lot of us think that the ultimate telescope would be, uh, to use the sun as a telescope. So the sun has intense gravity and it bends light. So this was an experiment that Arthur Eddington did to prove Einstein right. Uh, general relativity. He took photographs of the stars during, um, a lunar total eclipse, and he noticed that stars seemed to shift right next to the sun. And so, he used that to figure out how much light bends. So whenever you have light bending, that's a telescope, that's a mirror. So you can take light that's coming from behind the sun, it'll bend to a focus. And that focus point, we know where it is, you can calculate it. It's about 550 times further out than we are around the sun, so 550 AU. And along... If you just travel out in a line from that point, it's called a focal line, you put a telescope there, it would essentially have the collecting area-... of the sun. So you could image continents, rivers, even cities on a nearby exoplanet if you could put something there. It'd be wild. That is, that is the ultimate, in my book, for what an alien would do. If they wanted to observe Earth, they would just, behind their sun, they'd stick one of those telescopes and they'd be able to monitor a hell of a lot about the Earth from there.

    2. JRJoe Rogan30:47

       And this is just with our understanding of telescopes and our understanding of viewing things. And clearly, you could imagine a world-

    3. DKDavid Kipping30:55

       With known physics, yeah.

    4. JRJoe Rogan30:56

       Yeah.

    5. DKDavid Kipping30:56

       With known physics.

    6. JRJoe Rogan30:56

       You can imagine physics that are a million years more technologically advanced-

    7. DKDavid Kipping31:00

       Sure.

    8. JRJoe Rogan31:00

       ... and innovations that we can't even comprehend-

    9. DKDavid Kipping31:02

       Yeah.

    10. JRJoe Rogan31:03

        ... can't even conceive of-

    11. DKDavid Kipping31:04

        Yeah.

    12. JRJoe Rogan31:04

        ... that change everything.

    13. DKDavid Kipping31:05

        I mean, I mean, even with this telescope, you can't see people, right? You wouldn't be able to image Earth. You wouldn't be able to read, like, the headlines on a newspaper on someone's doorstep. It's not powerful enough to do that. If you wanna do that, you'd have to visit the system. And so we're talking about doing that as well. So there was this Project Starshot that wanted to fly a probe directly towards the nearest star, fly by super fast, snap a photo, and beam it back. 'Cause that way, you could actually get even better resolution, right? You could really dial in and see roads and structures on the surface.

    14. JRJoe Rogan31:33

        How long would it take for that beam to get back to us?

    15. DKDavid Kipping31:36

        Well, it's four light years away, 4.2 light years away.

    16. JRJoe Rogan31:38

        So it would take four years for us to get the image?

    17. DKDavid Kipping31:39

        Yes, and it would take about 20 years to do the journey at the speeds they were talking.

    18. JRJoe Rogan31:42

        Wow.

    19. DKDavid Kipping31:42

        They wanna go 20% the speed of light. So they'd take 20 years, take a photo, so 24 years altogether.

    20. JRJoe Rogan31:49

        Wow.

    21. DKDavid Kipping31:49

        So this was Yuri Milner's brainchild, and his dream was that he could see a photo in his lifetime of another Earth-like planet.

    22. JRJoe Rogan31:54

        Wow.

    23. DKDavid Kipping31:54

        And that's pretty much the best way we have to really pull that off in human lifetime.

    24. JRJoe Rogan31:58

        Is the work being done to try to make that happen?

    25. DKDavid Kipping32:01

        Yeah, so I'm not sure the current status of Starshot. Um, Yuri put $100 million up, I believe, for, you know, his own money, and I think Mark Zuckerberg came in on it, and they were like, "We're gonna try and do this." Um, I wasn't part of that project, but I was inspired by it. And I actually, um, came up with a twist on it recently called TARS from Interstellar. (laughs) You, you know TARS from the movie?

    26. JRJoe Rogan32:25

        What was TARS?

    27. DKDavid Kipping32:25

        It's like a robot thing-

    28. JRJoe Rogan32:27

        Oh, okay.

    29. DKDavid Kipping32:27

        ... that's in the movie. It's called TARS. And so I came up with, uh, a twist on, on their idea. So let me explain their idea quickly first, and then I'll give you my twist. Their idea is like, if you really wanna go to the nearest star system, you're not going to do it with a giant spaceship. That's just, you know, uh, we can't build anything that advanced right now. The most realistic thing we can do is to get a tiny, thin sheet of material, like imagine like, um, a piece of Mylar, a piece of, uh, aluminum foil, and blast it with light, with a laser. And so they're talking about sort of 100 gigawatts of laser power, right? So just kind of crazy amounts of energy.

    30. JRJoe Rogan33:01

        Is it there?
11. 35:17 – 44:00

    Fermi paradox, megastructures, and why we don’t see obvious cosmic engineering

    1. JRJoe Rogan35:17

       SimpliSafe system with professional monitoring and your first month free at simplisafe.com/rogan. That's 50% off with your first month free at simplisafe.com/rogan. There's no safe like SimpliSafe. I mean, I mean, the possibility of life has always been, like, in front of our face. There's just, the, the cosmos is so great and so massive. You've got the Fermi paradox, like, where are they? Why aren't they here? And then you've got what's happening here on Earth, and it just always makes me wonder, like, how far do things actually get before they fall apart? Do they always fall apart?

    2. DKDavid Kipping35:52

       Yeah.

    3. JRJoe Rogan35:52

       Has it... Or do they always become non-biological and not have the need for all the things that we do that show signs of life?

    4. DKDavid Kipping36:01

       Yeah.

    5. JRJoe Rogan36:01

       Like, there's certain gases that biological life exceeds. Like, what, what could, what could be out there, could be something beyond our wildest imagination, like many iterations of artificial intelligence-

    6. DKDavid Kipping36:17

       Yeah.

    7. JRJoe Rogan36:18

       ... many down the road, to the point where it's not even recognizable as life and doesn't even have to have a physical form?

    8. DKDavid Kipping36:24

       Mm-hmm. Yeah, obviously if it's completely unrecognizable, there's nothing we can really do to detect it. But, uh, when we look, I mean, we basically know two things about the universe in terms of life in it. We know that we have not been colonized, right, as far as we can tell.

    9. JRJoe Rogan36:36

       Allegedly.

    10. DKDavid Kipping36:37

        Yeah, allegedly.

    11. JRJoe Rogan36:38

        Depends on whose, uh, YouTube videos you watch. (laughs)

    12. DKDavid Kipping36:40

        But let's talk... (laughs) ... let's, let's talk about, like, a hard colonization-

    13. JRJoe Rogan36:45

        Yes.

    14. DKDavid Kipping36:45

        ... where it's, like, literally-

    15. JRJoe Rogan36:46

        They're everywhere.

    16. DKDavid Kipping36:47

        ... it's transforming the freaking planet-

    17. JRJoe Rogan36:49

        Right.

    18. DKDavid Kipping36:49

        ... into machines.

    19. JRJoe Rogan36:50

        Correct.

    20. DKDavid Kipping36:50

        Like, that clearly has not happened here, right?

    21. JRJoe Rogan36:53

        Right.

    22. DKDavid Kipping36:53

        We're not gray goo on the surface.

    23. JRJoe Rogan36:54

        Not yet.

    24. DKDavid Kipping36:55

        So we know that hasn't happened, yet, and we also know... And the universe, you know, the, the galaxy's old, it's 13 billion years old, so there's, there's a heck of a lot of time for that to happen. You know, one of the, one of the strangest, uh, facets of our technology is that it's already fast enough to explore the whole galaxy. If you take Voyager 1, Voyager 2, it was traveling at 15 kilometers per second. So that would get you across the entire diameter of the galaxy in two billion years, and the galaxy's 13 billion years. So Voyager 2, at Voyager 2 speeds, crappy alien technology out there could already have spanned the whole thing if they just arrived early enough. So it is a problem, um, and this is called Fact A, Hart's Fact A. This clearly hasn't happened, so that's one thing we know for sure. And the other thing we know for sure is that when we look out, we don't see, you know, we look at these stars like Stevenson and, uh, Proxima Centauri, we don't see engineering on them, as, as far as we can tell. We don't see stars which are obviously got megastructures around them, obviously been engineered in weird ways. We don't-

    25. JRJoe Rogan37:57

        And when you say megastructures, you're talking about, like, literally an artificial planet-sized thing?

    26. DKDavid Kipping38:01

        Yeah. I mean, huge structures could be built around these things, like Dyson spheres, and people have talked about doing it for messaging. Like, you could put, like, sheets of material that were planet-sized, and as they block light from the star, that would create, like, a Morse code, where you can actually message people for billions of years. You would just build these stable sheets of material, and they would just orbit round, no power system required, right, an orbit doesn't require power. It would just orbit around for billions of years, and every time it eclipses the star, there could be some intricate pattern of pulses. And so that way you could communicate for, for a very long time. You know, we've, we've thought of all these wild ideas, and we just don't see any of that. So it does seem, as far as we can tell, that the universe is completely natural, and that is mind-blowing. Because you're right, like, it seems if it's happened here, why the hell shouldn't it happen elsewhere? Why isn't someone else-

    27. JRJoe Rogan38:50

        Right.

    28. DKDavid Kipping38:50

        ... with AI going crazy? Why hasn't someone else gone even further than that, gone to the next level? So, and the thing that really drives me wild with this is, is the Earth is like a paradise, right? If you look at it, these are the stars, these are the planets. The Earth is unusual. Most stars do not have an Earth-like planet.

    29. JRJoe Rogan39:05

        Correct.

    30. DKDavid Kipping39:05

        It's at, like, a level of maybe one, two percent at best. And yet here we have the Earth. It not only is an Earth-like planet, it has the right conditions for life, it has life on it, so an alien could use their sun-sized telescope to figure that out. They'd know we were here. They would know not only we're here but that there is complex life on this planet. So for three and a half, three billion years, there was just simple life, just single-celled life on this planet. Multi-cellular life is a recent thing. So presumably that's rare, right? If, if most of the time it's single-celled, most of the planets out there presumably even if they have life on them are in that state. And then further, there's us here (laughs) , right? And we're going through this, this transitional point as a human society. So you think if you're an anthropologist, this would be, like, an incredibly fascinating world to study.
12. 44:00 – 1:24:22

    UAPs as a scientific problem: false positives, pilot reports, and instrumentation

    1. JRJoe Rogan44:00

       But when you hear about, uh, particularly the ones, the, the stories of UAP or UFO encounters, the ones that intrigue me the most are the ones that are military pilots. The people that know the difference between a flock of birds and weird anomalies. When... Y- Are you aware of the Tic Tac incident?

    2. DKDavid Kipping44:19

       Yeah. Yeah, yeah.

    3. JRJoe Rogan44:20

       Yeah. So when you hear about things like that, and you... Uh, in my mind, there's a couple possibilities. One, super advanced blacklisted military... Some sort of a propulsion system that they've been working on for decades, completely in secrecy, and they're testing them o- off of areas where you have a lot of military activity-

    4. DKDavid Kipping44:42

       Mm-hmm.

    5. JRJoe Rogan44:42

       ... which is where these things do take place.

    6. DKDavid Kipping44:44

       Yeah.

    7. JRJoe Rogan44:44

       One of 'em was San Diego, that's the Nimitz, and the other one, the Ryan Graves footage, the stuff that they get, that's on the East Coast.

    8. DKDavid Kipping44:50

       Mm-hmm.

    9. JRJoe Rogan44:50

       But it's all in areas where they already do military training exercises with fighter jets. So it, it would make sense that that's where you... If this was the United States government doing that stuff, they would do that. But when you get back to, like, 2004 and you're talking about something that can go from 50,000 feet above sea level to sea level in w- less than a second. Like s-

    10. DKDavid Kipping45:10

        Yeah.

    11. JRJoe Rogan45:10

        I think it's seven-eighths of a second it went. You have, uh, visual confirmation, you have radar, you have video of it, you have two different jets that see this thing, they... No one knows, understands what it is. It flies directly to their cap point, where their meet-up point was supposed to be. The whole thing's nuts.

    12. DKDavid Kipping45:26

        Yeah.

    13. JRJoe Rogan45:26

        It's, it's aus-

    14. DKDavid Kipping45:27

        I, I would love to know what the hell happened.

    15. JRJoe Rogan45:29

        Yeah.

    16. DKDavid Kipping45:29

        I think, like everyone, I'm fascinated by it.

    17. JRJoe Rogan45:31

        You can't throw it away. It's one of those ones you can't throw... I, I throw most of them away. Most of 'em... I, I, I love UFO stories 'cause they're fun.

    18. DKDavid Kipping45:40

        Yeah.

    19. JRJoe Rogan45:40

        But most of them, like, could be anything.

    20. DKDavid Kipping45:42

        If there's something shady going on, yeah.

    21. JRJoe Rogan45:42

        Could be anything. Could be people want attention, could be military exercises, could be mass delusion, could be people just love to be special and have had some sort of an encounter.

    22. DKDavid Kipping45:54

        Yeah.

    23. JRJoe Rogan45:54

        Which they do. It gives them some sort of social credit to have some sort of an encounter with a, a thing and they exaggerate, and people love, love-

    24. DKDavid Kipping46:01

        Yeah.

    25. JRJoe Rogan46:01

        ... to exaggerate.

    26. DKDavid Kipping46:02

        Yeah, I'd love to make this ingestible to science. That's sort of been my goal.

    27. JRJoe Rogan46:07

        Yeah.

    28. DKDavid Kipping46:07

        Like, how can science take a hold of this? And, you know, when we do these experiments... I mean, I told you about this, this moon that I thought I'd found, and it turned out it was the instrument being crazy. Right?

    29. JRJoe Rogan46:15

        Yes.

    30. DKDavid Kipping46:15

        'Cause sometimes instruments do crazy stuff-

Episode duration: 3:00:08