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  • It's that time of the year again.

  • It's the Nobel Prize is always tells my phone up.

  • You never know, but again overlooked.

  • Yeah, I just need to check the number I called it.

  • Yes, I'm feeling a bit smug about this because about five minutes before the announcement, I suddenly had this feeling who was going to win on.

  • Sure enough, they did.

  • Or at least they want half the prize anyway.

  • And the other half of the prize went to a guy called Jim People's Good Call.

  • That's a siege in people's get path.

  • Nobel Prize.

  • He's regarded, I think, is the father of modern cosmology.

  • Did you put a bet on or I should have done shit.

  • Really?

  • Yeah, but no, I didn't.

  • It was literally five minutes before the announcement.

  • It wasn't that clever of prediction, because I was certainly wasn't the only person predicting it.

  • And it's been bean sort of one of the runners and riders for a number of years now, But I sort of thought it was their time.

  • It's a slightly strange award, and actually so, the citation reads, was awarded for contributions to our understanding of the evolution of the universe in Earth's place in the cosmos, which could be pretty much for anything.

  • Really, because that covers pretty much everything there is.

  • But Jim Peebles is a cosmologist.

  • Andrei is really one of the towering founding figures of modern cosmology in that he did a lot off the work.

  • He was part of the group that was predicting the existence of the cosmic microwave background.

  • He did a lot of work about the growth of structure in the universe Thean impact of dark matter on how structure would grow So really, I mean, he is if you if you teach a course on cosmology, in large part, you're talking about his work.

  • The model, which is fitting the debtors so well, has his influence on every single part of it.

  • He is a theorist, but he's one of those theories who actually maintains a very close link to the observation.

  • So some of his work has actually, he's written papers which are presenting observational data, but MME.

  • Or in a fairly theoretical framework, so you would think of him as a theoretical astrophysicist.

  • He's just demonstrated that in modern cosmology, these air, the key ingredients, we look like we need.

  • And he was there at the start of each one of them, playing a role so he could be properly regarded as the father of the subject.

  • The expert says they're on your board.

  • Well, the other of modern cosmology.

  • Yeah, that's what they defended to come.

  • I did a tutorial.

  • Today we have tutorial system here at nothing and where all the first years get to have a usually six in the group.

  • I screwed up.

  • I had to do 12 because and so I thought, Well, you've got to tell them about the Nobel Prize.

  • A ceased the bit.

  • I know about it.

  • If you were talking about Jim people, you wouldn't say I he did so and so because there's just so much has contributed.

  • So the other half of the prize was shared between Michel Mayor and Didier Kilo.

  • Andre worked on studying exoplanets.

  • They still work on studying exoplanets planets outside the solar system on it was awarded for.

  • And then we get the exact wording here for the discovery of an exoplanet orbiting a solar type star.

  • So it was really their discovery in 1990 fire was what kicked off the entire field of explain it studies because, like extra planets these days, like candy and they're like there are many, many thousands of them.

  • At that point, it was only one, actually, that's not quite true because there were other planets and that z interesting the way they worded the citation.

  • This is an ex, a planet orbiting a solar type star.

  • The first exit plan, it was actually found orbiting a pulsar, a neutron star rotating neutron star, which is a very weird system.

  • And no one really expected to find planets around pulsars on.

  • So it was clearly something very strange.

  • And so although it was interesting, it was like everyone was Well, it's nothing like the solar system.

  • So it's not really a planet in the sense that we would understand it.

  • There are also tentative discoveries of planets orbiting giant stars that preceded the maior que lo discovery.

  • But this was really the first announcement of one which we would sort of equate with something like the solar system.

  • So it was a solar type star, very like the sun with a planet in orbit around it.

  • Do you happen to know, like what star it was it was obviously a nearby.

  • It was It's 51.

  • Pegasus is the star on the Planet School 51 Pegasus B is about 50 light years away.

  • It's very ordinary stars to say it's a G type stars every like the sun, a little bit more massive.

  • Only 1.1 times the mass of the sun is a tiny bit more massive, but really almost a twin of the sun.

  • Very book standard kind of star.

  • What method did they use toe discover?

  • So they use this radio velocity method there now a whole slew of methods that are used for discovering and studying exoplanets.

  • But one of the foundational techniques and the one that made this first discovery was his radial velocity technique, where if you got a star, when you think of a planet in orbit around it, the sort of simple pictures and the stars stationary in the middle of the planets orbiting around.

  • But of course, they're actually tugging each other on sort of orbiting around their mutual center of gravity.

  • What that means is that the planet is tugging the star backwards and forwards as well as the the start talking the planet backwards and forwards.

  • So the star is actually oscillating.

  • And so sometimes it's moving towards you.

  • And sometimes it's moving away from you on by studying the specter of the star looking those little dips where there are a spectral lines in the star, you can see whether they're being shifted.

  • Dr.

  • Shifted towards the red end of the spectrum or the blue end of the spectrum.

  • So you make sure that backwards and forwards woman of the star on that gives you a measure off the mass of the thing that's orbiting around it as well as how rapidly it's orbiting around it, by how quickly the thing also lights backwards and forwards.

  • You know, that's a That's a good method, I imagine.

  • Imagine that method had been thought off for quite a while, and all the astronomers in the world have access toe telescopes and telescope time.

  • What did these scientists do that made their may would be first like what method or trick or idea that they have that made them the winners.

  • So there's a couple of aspect here.

  • Firstly, people weren't really looking that hard at the time because there was no expectation that you'd actually be able to detect much because we had this.

  • So if you think about what's easy was easy to detect in this case, you want something where there's a strong gravitational pull between your planet and the star to tug it a long way, So it's gonna be a big planet.

  • So there's two things you wanted to be a big planet.

  • So is massive.

  • So it'll take nothing back with a voice that actually you want them close together.

  • So the pull of gravity strong so that the movements are bigger.

  • And so what you really want is a planet like Jupiter close to the star.

  • Now, at the time, we only knew about one solar system, and Jupiter, in our solar system is a long way out, as is the way with scientists.

  • You know, if you've only got one of example of something, you convince yourself that that's the way the universe works.

  • So we had all these ideas at the time back in the 19 nineties and before that, Actually, Jupiter, like planets, only existed in the outer reaches of solar systems and things close to their stars of roll little things like mercury on earth, which you wouldn't be able to detect.

  • And so because of that, there wasn't really a huge expectation that we'd be able to detect this kind of effect of what these guys actually found was something that's about half the mass of Jupiter very close to a star.

  • And so, actually and subsequently, of course, we found many of these hot Jupiter like planets.

  • So Jupiter like planets, which is close to the star.

  • And so it turns out that actually the universe doesn't work the way we thought it did back then.

  • And there are mechanisms where even if a big planet forms a long way out in the solar system, there are meth mechanisms by which you can kind of McGraw migrate inwards towards its stock s o.

  • They found something that no one was really that much expecting to find, which is why there wasn't a huge rush to try and find these things.

  • The other thing is they had some very clever instrumentation.

  • They actually built a custom built spectrograph that allowed them to measure very small Dr Shifts.

  • They were down that sort of tens of meters per second that they were measuring these one was in the stores, which did require very good instrumentation, very stable instrumentation where you can actually calibrate things with that kind of accuracy to really measure those very small ships.

  • So you couldn't have just had, like, an off the shelf night of Vot and have found us.

  • You probably could now with vot.

  • But in the 19 nineties, no, he really wanted the custom built into It wasn't on that larger telescope.

  • It was I think it was a two meter telescope.

  • So even by then, those standards the standards of the 19 nineties, it wasn't a particularly huge telescope, but it was just a very clever spectrograph.

  • And they were looking for something that no one else is really looking for as an astronomer.

  • And you're an astronomer.

  • In the nineties, I was.

  • Do you kick yourself and think, Oh, I could have done that.

  • That would have been like a week's work, and I could have I could have been the one to find it.

  • So the interesting thing is, before their paper in the 19 nineties, in the 19 eighties, let me show you another.

  • So let me show you their paper.

  • So here's their paper published in 1995 A Jupiter, Mass.

  • Companion to a solar type star.

  • Nobel Prize right there and it's you know, it's actually not particularly long paper.

  • It's not got many pretty pictures in it.

  • Photographs.

  • Not even a picture of the star.

  • Even a picture.

  • No, nothing spectacular about it at all.

  • I mean, you know, nice looking data.

  • There he is there.

  • So here's the walking backwards and forwards of the star, so sometimes it's going away from us.

  • Sometimes it's coming towards us and you can see So that is the scale 50 meters per seconds.

  • Are this small ships that you actually measuring here?

  • So that's the wobble that they were measuring.

  • So here's the interesting thing that was the 19 nineties.

  • In 1989 this paper came out the unseen companion off telephone number, a probable browned off, and it turns out they had actually also discovered a Jupiter like planet.

  • He's on there as well there he's actually my O is on there as well.

  • He's one of the authors, but the primary move with this guy called Dave Latham was actually in an office just over the corridor for me at the time because I was a PhD student and he was a proper serious scientist at that point.

  • A si FAA in Boston.

  • He wasn't very excited about this result when he was a bit excited, but he was, actually, you know, because I'm the game, it comes back to the fact that no one was expecting to find planets and the reason why he didn't know that he'd found a planet.

  • So brown dwarfs a sort of one up from planets that sort of failed stars.

  • And no one was.

  • People were expecting to find Brown dwarf because we find buying restores quite a lot of the time, and they have different mass ratios.

  • And it wouldn't be terribly surprising if once in a while the little one turned out to be not quite making it as a star.

  • So people were not that surprised to be finding stars with brown dwarfs in orbit around them because they're basically just very closely related binary stars that we know exist failed binary.

  • It's a 1/2 of its kind of failed to ignite.

  • So 1/2 is a star of the other half didn't quite make it because they weren't expecting to find planets.

  • He convinced himself he hadn't found a planet.

  • And the reason why there's an ambiguity, because you might think, Well, you know, we know what masses brown dwarfs, that we know what matters.

  • Planets I wouldn't have known.

  • Turns out there's an ambiguity in this method, and the ambiguity in this method is I kind of drew this when I was waving my hands around.

  • I did it like that.

  • But we don't know whether the systems like that or whether it's sort of do it that way that way like that.

  • Of course, if the planets orbiting that way, you don't see that the star is still moving, but it's being tugged in the plane in the sky, so you don't see these doctor ships.

  • So this is Amber.

  • You and of course, you could have anything in between.

  • So actually, if you see a certain movement, it could be like if it's, you know, you see a certain movement.

  • It could be a relatively low mass thing that's in the plane in the sky.

  • So we're seeing all the movement of the style, or it could be it's almost in the play much more massive thing and actually these things, well, jerking around all over the place.

  • But we don't see most of the motion because most of it's in the plane in the sky rather than towards us or away from us.

  • You've got to get lucky.

  • It's kind of you needed to be punching you in the face rather than wobbling around to get the biggest signal.

  • You really want to be lucky and just catch.

  • Catch a thing here, John.

  • So you see the biggest signal because it's a hat.

  • Less ambiguity.

  • You can't tell really directly from the observation whether you're seeing a brown dwarf kind of in the plane in the sky, close to the plane, the sky or a planet close to a John on.

  • Because they had the expectation that they shouldn't be finding the planets, they convince themselves that they were seeing a brown dwarf star by Henry 30 close on.

  • It was a bit unlikely because, actually, it has to be surprisingly close to face on for it to work, but they sort of convinced themselves they do actually say somewhere in the paper, or it could be a large planet, so they do actually at least make you know, say, we might have found a planet.

  • The extra thing that my own Kahlo did is they also looked at the properties of the star, so they actually could measure how fast the star is rotating because you can see 1/2 of its stars rotating.

  • 1/2 of it's coming towards you.

  • The other half's going away from you, and so you can actually see the what you end up seeing is a kind of a broadening of the lines.

  • So instead of seeing the line wobbling, you see part of the line being shifted one way part of it the other way.

  • The net effect of that is you see a slightly broader line so they could measure the rotation of the stall kind of the least.

  • But again, that's the same thing.

  • What is it, a start rotating in the plane in the sky?

  • Or is it rotating a John?

  • But they knew some of the properties of the star.

  • You could just make observations of it, find out what kind of star it is, and we know how far stars typically actually rotate that are of that type.

  • So they have these measurement off this kind of one component of how fast the thing's rotating on.

  • That could be either a very fast rotating star, that sort of pole on, or it could be a relatively slowly rotating star.

  • That's a John, but we know intrinsically how far stars like this actually rotate from that.

  • You can figure out that actually, this system is relatively close to a John.

  • So there's one more leap here, which is that as long as the Stars axis of rotation is the same as the planet's axis of rotation, which, for example, it is pretty much in the solar system.

  • The sun's rotating about kind of the same access that the solar system is, then that actually tells you that the system has to be relatively close to a job.

  • And once you've got that, then you know you found a planet.

  • So that was the sort of the extra bit.

  • I guess that is what really got them.

  • The Nobel Prize plus, actually just the confidence to say we've found something that no one expected to find.

  • So in the future of one day we go and visit other systems and other planets and weaken somehow do this.

  • This will be this plant, this particular Nobel prize.

  • I wanna be a good one to visit, wouldn't it?

  • To be, like historic wanted to be, like visiting, like for humanity.

  • This was This was a historic site for us.

  • It probably.

  • I mean, it's not the easiest one to get to because it is 50 light years away and we know No.

  • We now know about planets.

  • You know, there are only a few light years away s so it's probably not the 1st 1 that would ever get visited.

  • But, yeah, when it becomes routine, it will become one of the stops on the tourist trail.

  • I suspect there's Of course, there could be other planets in this system.

  • We've just seen this one fairly massive Jupiter like planet very close to the star, which really wouldn't be very hospitable because it's gonna be a gas giant and it's gonna be very hot and very unpleasant.

  • But who knows?

  • There could be other planets further out in the solar system.

  • Father of modern cosmology.

  • Does that mean there's an older cosmology like Where does it waited?

  • Waited old cosmology, transition to modern cosmology.

  • I'm giving the transition time around the 19 sixties, which, by the way, is another important time for the sort of the e book of Higgs and Cable and Brows and Uncle Aaron people.

  • The discovery of the cosmic microwave background radiation.

  • I think that kind of transformed the field from being one that was full of speculation on dhe promise in solving Einstein's equations without really knowing what the background material waas in the universe to first.

  • The first time we established that this radiation, this remnant of the hot Big Bang that emerged when the first atoms were formed, safe 400,000 years after the Big Bang and then just propagated outwards for the next 3.8 billion years that the detection of that in the 19 sixties 1965 facts.

  • It was announced by Penzias and Wilson that where the associated a temperature to this radiation that I think is what you might call I'm calling here.

  • That's kind of the start of modern cosmology, and people's was there.

  • In fact, it's no very well known, but the paper by Penzias and Wilson, which is one page long way, are busting a gut writing all these long page, one page paper about the third or fourth line, having announced that they discovered this radiation that they don't really know what it is.

  • They say that in the preceding paper in the Journal, which is Jim People's Paper with Decay and Roll and Wilkinson, they say they've come up with an explanation for what this could be.

  • And it is.

  • In fact, you know, the microwave background radiation at the temperature around at the time.

  • They say 3.5 Calvin.

  • And suddenly it's now about scene is about 2.7 Calvin.

  • But that's that's okay with 3.5 plus and minus still 0.1 so that when they were perfectly okay, But people's was there.

  • And in fact, not only was he there, he he's the one that, actually in the previous paper, the one that literally appears before it, which is a mind blowing four pages long.

  • So that's a huge paper.

  • By comparison, he's the one, along with his co authors, who suggest that actually, this remnant radiation is linked to the hot Big Bang and and that it's got these thermal properties.

  • It it's that I think, which is really key that that you can pin down.

  • There has been one of people's main contributions here that he recognizes ever significance of the radiation has been linked to the early universe Onda</