The Nobel Prize has just gone to three astronomers Reese, Pull Water and Schmidt, who between them get the whole prize.

And I think the way it spits up is pull.

Motor gets half of it on recent Schmidt.

Get 1/4 each.

Actually, it turns out one of these three years of mate of mine, Brian Schmidt and I were graduate students together many years ago.

In fact, he was, you know, a year or so below me in graduate school, so little Brian has now won their well prior to shot past me to glory on.

Clearly, I've not been doing the right things in my career, but I'm very pleased, for it means one of the nicest guys I know.

So I'm delighted that you got is everyone in the building talking about this today?

If you bumped into people in the coffee room and they're all saying, What do you think?

I want to talk about it, but it seems like a lot of people haven't been.

I came into the TV room and told all the grad students and it didn't seem to care very much, but maybe it was too early in the morning.

They've won the prize for very carefully, measuring the brightness of ah, handful of little dots and learning that they're not as bright as they expected them to be.

And this just has very fundamental implications for measuring the fate of our universe.

Brian's very interesting guy.

Uh, actually, he lives in Australia now.

Hey, has many talents, one of which is, for example, you runs his own vineyard.

He makes his own wine, which I'm told is very good.

I get to actually taste it, but I'm told it's extremely good.

And in fact, Brian and I have a bet because I bet a number of years ago that this result was wrong on.

So I have a bet of a crate of his wine from his vinyard against the really good bottle of malt whisky that his results were going to go away.

And I think now he's won the Nobel Prize.

I'm gonna have to pay him, to be honest.

So the science that they've been doing is that these guys have been studying a particular cup of supernova.

I think would have type one a supernova.

Essentially, it's just a particular kind of supernova.

You're just exploding stars stars at the end of their lives.

On this particular designation refers to a particular kind of supernova, which has a rather unusual property, which is that they're all the same.

And it's quite unusual in astronomy to have things ritual the same, you know, most types of supernova, for example.

Some of them are bright to someone fainter.

The interesting thing about this type of supernova is that when you've seen one, you've seen them all.

So actually, they all seem to blow up in exactly the same way.

That kind of dull because you doesn't send you.

If you've seen one, you've seen them all.

But actually that's also what makes them exciting, because one of the things we struggle with in astronomy is things which are just kind of a standard things that we can actually compare to one another, so that what's known in astronomy as standard candles, they're all the same brightness.

If you have something that is a standard candle, it means, you know what?

It's intrinsic luminosity.

It's intrinsic.

Brightness is because when we make observations of objects in the universe.

Sometimes if we don't know how far away they are, we don't know if we're looking at, you know, a bright searchlight very far away or a little glow worm right next door.

But if we know the intrinsic luminosity, if we know that what we're looking at is 100 watt bulb, um, then we can fold that into how far away that object is based on how bright it appears to be.

But what's thought to happen is it thought.

These are binary stars.

You got two stars in orbit around another.

One of them's a white dwarf.

No, white Worf is the end product of mean.

You know, a medium class star like our sun at the end of its life, puffs off its outer layers, collapses but can't collapse all the way because of something called electron degeneracy pressure holding it up.

So this white dwarf stays there for a while and the others just a normal star.

And during the course of its lifetime, this normal star is losing some of its material onto the white dwarf.

Now think about white walls is that they have a maximum mass at which they're stable, called Chandra, seek our limit, and that's 1.4 times the mass of our sun.

And so as long as it's less than that, it'll just sit.

There was a white dwarf, and this other star will dribble Maura, Maura, Maura stuff on it until eventually it will dribble that little bit too much on That'll tip it over this edge and at that limit, this is an unsustainable system, and it triggers an enormous thermonuclear reaction and causes this star to explode.

And that's why we think they're all more or less the same.

Because actually, it's always at this same mass where these things go unstable.

So it's not like they're different masses of white dwarf exploding.

It's just when they tip over this Magic Maskell the child's sake, our mess that they will blow up a supernova so they're all the same.

And these things can be as bright as an entire galaxy for a couple of weeks.

And because they've come out of this sort of standard origin process, this is why they're very good candidates to be standard candles.

The supernova physics, although it's interesting, is not the thing They got the price for the thing.

They got the price or is using them as the standard candles, using them as a way to sort of measure the entire universe on because they're so bright, we can see them at enormous distances away.

We can see them right across the universe, which means we really can use them to probe the properties of the universe as a whole.

They found that the ones in the distant universe were slightly dimmer than expected, given their distance And what this is telling them what this is telling us is that something?

The universe itself has expanded more than we think it happened.

It should have.

This was surprising because actually, cosmologist before this thought that the universe was de accelerating, going slower because if you can imagine, universe is expanding.

Which you know that from Hubble in the 19 thirties that the, uh the mass would push stuff and make it go slower.

But they found was accelerating, which was completely unexpected.

The genius of it waas that it's very, very in ambitious project to do.

I mean, ah, it involves optical telescopes.

By the way, this is the first number prize ever that use off the cool telescope in astronomy has been once for radio, but never for optical.

The challenge of actually making these observations and gathering enough supernova thio make the measurements that you need to is quite a difficult one because supernova rare particularly type one a supernovae which which is what's needed for this project.

The genius behind it was that they use the telescopes in a way that was novel, that they went and they search for these thes stars blowing up.

And if you, you know, 20 years ago when they started this kind of thing, if you told a telescope allocation committee I want to take pictures of Galaxies and then re take pictures of Galaxies to find supernova, and in the distant universe they would have thought you were crazy and they think they did have a hard time getting telescope time to do this.

What these projects did was put together an industrial supernova factory, in a sense, so they got telescope time.

They had big enough cameras that they could serve a large patches of sky around New moon when the skies dark and then go back and revisit those same patches three weeks later and then simply by blinking the two images together, you look for a little tiny change, a little doctor coming up, perhaps associated with galaxy, which is gonna be that supernova.

And because you're serving such a large patch of sky, you statistics tell you that you will find some super No, but you don't know exactly where they will be.

But you will get a sample and those samples.

Then you take away to other telescopes and you follow them up because what you want to do, the important thing for supernova as a standard candle is to catch them at their peak brightness.

When these guys first started finding the results in the 19 nineties, this was a complete game changer.

You know, it was not what anyone was expecting.

Everyone was expecting that actually, gravity was going to be slowing down the expansion of the universe and therefore probably you know, that they should be measuring the deceleration effect.

And they started measuring this acceleration effect, which is kind of overturned that almost are complete understanding of cosmology.

Ondas Adam led us to a worrying about things called cosmological constant and dark energy and all the things that now now going into modern cosmology that seemed to be leading to this accelerating expansion of the universe.

But this was really the observational result that set that whole ball rolling bronze gonna be a busy man today.

I suspect he's gonna I haven't yet bothered to try and put a call through to him because I think he's gonna have plenty of people on the phone to him today.

When you get in contact about this whisky, then I think I'll wait a few weeks.