The Universe: What Remains to Be Discovered?

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Hello, I'm Robin Ince.

And I'm Brian Cox.

And welcome to the podcast version of the Infinite Monkey Cage, which contains extra material that wasn't considered good enough for the radio.

Enjoy it.

This is the Blue Dot Festival and this is the Infinite Monkey Cage.

This is the first time for quite a while that Radio 4 have done a panel show in an open field.

Not actually.

Remember Parsons at Woodstock?

There was Nicholas Parsons at Woodstock.

Yes.

Some of the older people here will remember that of course halfway through the who's set Nicholas walked on and said I have to admit I am going to give there the both deviation and hesitation there for trying to put us

down

that was a correct challenge the Grateful Dead you have 17 hours now on my generation

quote unquote Reading 97 quote unquote Nigel Rees and Daphne and Celeste of course a lot of people forget about Nigel Rees being there but the reason that Daphne and Celeste were bottled off was due to a poorly thought quotation from GK Chesterton.

I've got to say to you not to spoil the myth or anything but I said I even I'll make some jokes up say anything so I could say kind of you and yours Donington

yeah you and yours I think Donington monsters of rock we just we're joined by Lemmy to talk about tinnitus

Lemmy Lemmy Lemmy

Gardener's Question Time Oasis Networth a classic

Gardner's question time opening for oasis a lot of questions about things that grew in the garden, many of them not legal.

So this is the first time that we have done the Infinite Monk Cage in an open field.

We have done festivals before, but basically you can't...

This is, how many of you have actually been to Jodrell Bank before?

Isn't the Lovell telescope one of the most beautiful pieces of human imagination turned into a structure to interrogate the universe that you've seen recently

We went we went we actually stood in the right in the middle of the dish didn't we what was about six months ago?

Yeah, yeah for our Einstein program.

We did it It was great we did this program about Einstein and afterwards we're sitting in the canteen and I asked Brian to explain a little bit more about general relativity and he did it very beautifully and someone had gone to go and get him a pie because that's how famous he is.

He doesn't have to get his own pies, they are brought to him.

And he leant forward, still smiling, bit into the pie and went, ow, ow, ow, it's boiling, it's boiling, right?

Which I thought was very beautiful because there's something wonderful about seeing a human being who understands the idea of the heat death of the universe,

but not the speed of the cooling of a pie.

So it was great though, it's such a beautiful structure.

It is a beautiful structure.

The fact that it can see out to the edge of the observable universe, as we talk about, 13 billion light years away, it's a tremendous thing.

I'm not going to give it it away though that is

what we're gonna be talking about is what we are yet to find out about the universe what we we still need to know about the universe so the official title is the universe what remains to be discovered brackets not dark energy or dark matter close brackets

because fans of monkey cage will know we've done that about six times and so our producer said we're not allowed to talk about dark matter and dark energy dark matter is 70% of the energy density in in the universe.

Dark energy is 70%.

Dark matter, yeah?

Do not tell anyone you saw that.

It's the most secret thing.

Oh my goodness.

What a brilliantly knowledgeable crowd this is.

Dark matter is 25%.

So we've got about 4.9% of the universe that we're restricted to talk about, but we'll make a good.

There's another reason we're not going to talk about dark energy, because even after every show we've done about dark energy, people have gone, well, what exactly is dark energy?

And you've gone,

yeah, it's a little tricky, that one, it's a little tricky.

So we have a great group of people.

Again, Ledger, and please welcome to the stage Associate Director of Georgia Bank Tim O'Brien, astronomer Paul Abel, actor and author Ben Miller, and singer and songwriter Charlotte Church.

And we're going to open with Hotel California.

So Paul,

that's a horrendous boys own tribute, act.

So we will get, this is, as I said, it is quite a bizarre thing.

We've never done this.

We are doing it properly.

Well, as properly as we've ever done it, but as it's going to be a discussion about what we have yet to find out about the universe.

And so we'll start off.

We'll in fact talk about the music that you heard when we came on

is a fantastic recent piece of music called Hello Moon, but it is not merely music.

And Tim, Tim O'Brien, I want to ask you, tell me a little bit more about why an audience here, a jodrel bank in the shadow of the Lovell Telescope, why they should be fascinated by what they heard as we walked on.

Because somewhat bizarrely, maybe, that dance track is made up of a remix of space sounds, some of them recorded with this telescope.

So the beat, the beat, the thud, thud, thud, thud that you hear is actually the thud of pulsars, the flash of stars that exploded thousands of years ago.

They spin like cosmic lighthouses hundreds of light years away, and we detect the the flashes with the telescope, take those radio flashes, and turn them into a sound.

And that sound gives that rhythm that we then built into that dance track.

So, should perhaps describe pulsars in more detail because they're fascinating objects in their own right.

Yeah, I mean, they're um, they're sort of basically things that are they're about the size, they're about the sort of mass of the Sun, so about one and a half times the mass of the Sun, but only about the size of a city,

so only about 20 kilometers across.

So, if you can imagine getting a giant pair of oven gloves or something and getting hold of the Sun and squashing it down to the size of a city, that's a pulsar.

Mass of the Sun, 20 miles across or so, rotating how fast it is.

Some of them rotate, the fastest ones rotate more than 700 times a second.

So, it's something that the mass of the Sun, the size of a city, spinning more than 700 times a second,

radiating out sort of beams of radio waves from the magnetic poles.

And as those beams sweep round, just like a lighthouse, you get a flash, flash, flash, flash.

And if we look at the local telescope over there, how distant are the pulsars that you can listen to?

So they're something like they range from a few tens of light years away to several thousand light years away.

So that's the radio waves we're picking up with that telescope have taken in some cases thousands of years to reach us, traveling at the speed of light, 300,000 kilometers every single second.

Well, Ben, your most recent science book is about trying to define what life is

and indeed looking at it as well from the perspective of possible extraterrestrial life.

Now, talking about pulsars, Justin Belburn, someone who said, well, initially what was called LGM1.

And I wonder if you can give us a little bit of background of

why a pulsar may have been given the tag LGM1.

Yes, well this is a brilliant story.

Dating back to a time when we were first switching on our radio telescopes and starting to look at the sky.

And of course, we just didn't know really what we might find.

And one of the possibilities was a signal from an alien civilization.

What if there was an alien civilization out there with radio telescopes broadcasting some kind of signal?

So I think this was something that all radio astronomers of the time were aware of.

And Jocelyn Belbinel,

as you say, set up a radio telescope.

This was in the late

about 1967.

She was doing her PhD, actually, and she was looking for a special type of a very active galaxy called a a quasar.

She built this very sensitive, for the time, radio telescope, and she was there at night, and she had the chart recorder paper, because there was no sort of electronic instrumentation.

You know, this was like a proper good old-fashioned chart recorder going along.

And she began to notice, when she looked at the readout, there was about two centimeters of what she called scruff

that appeared on the paper, which was this very, very intense signal.

And of course, then she lay in wait, and one night she managed to be there just at the right time to to switch the chart recorder pen so that it could really pick up the detail of the signal and it was a pulse.

Which is exactly what you might expect if an alien civilization had set up some kind of beacon, some kind of lighthouse, some kind of indication, here we are, come and have a chat.

So they called this source LGM after little green men.

It was slightly tongue-in-cheek I believe at the time, but there was a very real possibility and Jocelyn Belbinel was furious because she needed to get a PhD

out of setting up this experiment, and she felt absolutely

gutted because some alien civilization had decided to signal to her at exactly the frequency she was looking at and ruined her experiment.

But I remember we do a stargazing live here, as some of you might know, and we had a, about three or four years ago now, wasn't it, when we discovered a planet in the Kepler Space Telescope data?

And we asked Tim, we were all sat there going, I'd be brilliant if someone had a radio telescope.

And so Tim said, yeah, okay.

So we

swung it around to this planet.

And then at some point, the BBC said, what happens if we detect a signal?

In where?

In the broadcasting regulation?

Does it say we're allowed to do it?

Time would look at what to do.

What would a radio astronomer do?

What would you do?

You're the director of this telescope.

If you heard a signal, would you immediately go on Twitter and go,

there are aliens out there?

Well, okay, probably,

but officially.

In fact, we would want people to know, right?

So we would not keep it secret.

I mean, people think somehow we've signed some official secret site that says if you detect aliens, don't tell anybody, there'll be mass panic.

We haven't done that.

Nobody here has signed that.

We would want people to know because it'd be the most incredible thing we'd ever discovered.

But what you would do first, actually, is check you've got it right.

So, you would think you would actually think about it in the same way that the people at Cambridge, Jocelyn and Tony Hewish, but those people they looked at it and thought they did name it that, but they thought, you know, is it really aliens?

And they thought about it for months and they kept it quiet for months because they wanted to check what was going on.

So, there'd be a period of checking, you'd get your mate with another telescope to have a look, see whether they could see it.

But then, actually, you'd, you know, I think what we do, in fact, I had somebody else ask me this question quite recently: what would we do?

And it's not really written down.

So we'd be inventing it as we went along, to be honest, and we'd say, okay,

is it real?

We'll go to the International Astronomical Union.

We'll tell the union and see what they think.

So maybe

there's no protocol.

You would think...

I think we've signed up protocols.

Did we find?

I think we looked, and the only people we could find who had a protocol were Vatican City.

But they had some regulation, didn't they?

Bring the Pope.

So I don't know whether it's comforting or not that we don't have a protocol for what to do if we pick up aliens.

Is it comforting?

What people think?

Yeah, it's like the idea that if you had broadcast that on stargazing, that the second signal you get from an extraterrestrial life will be a cease and desist letter and being sued for they've invaded our privacy on Andromeda.

Yeah, or something like going, that Darrow Green's always on.

Charlotte, the first time, in fact, the very first time that we met was at another music fest, End of the Road, where at one point you were watching Sophie Ann Stevens and singing along, and someone turned to you and said, You've got a nice voice.

And you just said, Thanks very much.

But the first conversation we'd never met before is you kind of came up to me very quickly in a glittery outfit and just went, I love physics.

And

you know, people know that, obviously, that you've been interested in such a broader thing.

What was it about physics?

What is it that drew you into kind of the world of things like cosmology?

Do you know what?

It happened when I was at a news agent's and I was buying some completely pointless, worthless celebrity beauty magazine thing.

And I saw a copy of The New Scientist and I thought,

what am I doing?

Why am I just, I'm just, I wanna have a go at that.

And it sort of changed my life.

And I just found it, I just was absolutely fascinated by everything in it.

And that sort of then just ignited my, you know, just this idea of learning about all of this stuff.

And it was possible that, you know, I didn't have to be, you know, a proper boffin or

have to go to university to be interested and be able to educate myself, you know, even a little about these massive concepts.

But also, I found like an immense amount of comfort

somehow in this, you know, especially when it comes to things like quantum mechanics and just how odd some things about our

universe and reality and some of these huge ideas, these mind-bending ideas,

I found loads of comfort in.

Do you remember the first because there are certain facts where you just think this is a good entry point for anyone who doesn't think science is for them, like recently with gravitational waves, I was reading a piece by Marcus Chow, and when he was talking about the point of the merging of the two black holes, and that at that point of merging, the power output would have been the equivalent of 500 times the power of all the stars in the universe.

That's a really good opening idea.

If someone's not interested in that, you go, we won't be needing to ever talk to you again.

So, was there

an idea that you just saw and you thought, what, this changes so much?

I think for me, it was the idea of entanglement.

The idea of entanglement was just like, oh,

that is so cool.

It could be how far away.

Yeah, so yeah, the idea of entanglement just really, but also, and I suppose this is where lots of cod signs comes into it, which I also sort of love as well, just to explore.

But just it's how you can actually relate that to maybe like the human world or you know the the emotional human stuff that goes on.

So I actually wrote a a song with my partner called Entanglement, which is basically a sort of like a love song, but it's sort of about two entangled particles as well.

We should Paul, because

the main subject of this discussion is things we don't know.

And that idea, quantum mechanics, the way that that interacts, I suppose, with cosmology in the sense of relativity, that's one of the big things.

Perhaps you could start just by giving the one-minute description of why quantum mechanics and our best theory, the framework for cosmology, general relativity, doesn't fit together.

Right, okay.

So

a big admission on behalf of all theoretical physicists in this area, we don't have a quantum theory of gravity.

We do have quantum mechanics, it's brilliant, it's the reason why all your mobile phones work.

We have general relativity which is the reason why all your sat-navs work and they got you here today on time.

They both fundamentally disagree on the nature of space-time.

And that's really rather embarrassing, because it means you have to sort of choose whether you want to do physics of the very small or physics of the very large.

We don't want to have to do that.

It's very, very embarrassing to have be in that situation.

The reason why black holes are key to this is because around the event horizon of a black hole, we have quantum mechanical effects that are happening as well as gravity.

The two have to work there, they have to coincide there.

So this becomes a very good place to look for a quantum theory of gravity, how gravity works at quantum scales.

And when people started doing this in the 70s, one of the most remarkable results that came out of this this hybrid of the two theories, quantum field theory, was that black holes are not static, they're not dead, they radiate slowly over time.

And the fact that the smaller the black hole is, the quicker it radiates.

So far from being static dead objects, any primordial black holes that may have formed at the time of the Big Bang might now be evaporating.

And as they get smaller, the evaporation process runs away and they explode in a shower of gamma rays.

I mean, cosmological terms, it's not that impressive, but if one went off in this field, it would be enough to take out us, the stage, and most of this side of the planet.

So

a bit of respect for them, but these gamma ray bursts do exist out in the universe.

We don't know if they could be the final death throes of black holes.

I think I went over a minute, didn't I?

No, no, no.

Tim, gamma ray bursts, they're one of the big mysteries.

So perhaps you could describe gamma ray bursts from an observational standpoint.

Yeah, I mean, these were things that were discovered in the late 60s, and they were actually discovered by satellites that were put up to look for people violating the

test band, you know, testing atomic weapons.

So they were seeing flashes of gamma rays, thinking that they were coming from the Earth.

And in fact, it was a sort of pantomime it's behind you moment

because they were behind the satellites out in the distant universe.

So every so often, one of these things explodes, flash of gamma rays.

We had no idea what they were for decades.

We still don't know exactly, but we do know they're far away.

So they're scattered all over the sky.

That means they're not in our Milky Way.

They don't sort of track the Milky Way across the sky.

They're all over, very distant, probably explosions.

Our best guess is that there are explosions of massive stars, supermassive stars at the ends of the lines.

By very far away, how far do you mean?

Oh, I mean

many millions of light years, and in probably in most cases, billions of light years.

So, you're you know, when we when we think of it, when we look out in time, of course, the class in out in space, I should say, the great thing about astronomy is you're seeing back in time.

So, you know, you've got like a telescope that's a time machine, you look far away, you see far back in time.

So, these things are back a good fraction of the age of the universe.

So we're seeing billions of years into the past when these things are exercised.

Well I want to quickly ask

something.

Because we were talking about the idea of looking back in time, we should also cover the notions of time and the debates over

our understanding of how we believe we experience time.

Yes.

And then time as an idea within physics.

Yeah, I...

Time in physics is very interesting because we have sort of kind of like have two forms of it.

So and I think it's probably just me being stupid, but I've never really understood how time in quantum mechanics works.

It's not really like time in general.

Can anybody help it?

Can I just say how remarkable this entire event is?

To be standing on a stage and all these people listening to descriptions of the inability sometimes to match up quantum theory with our understanding of the nature of time.

It's not at all what it was like when the stereophonics played in.

We should say, have you got the now the one minute version of what on earth you mean by that sentence

what is it about time and quantum theory that's confusing well it's time in general i'm going to do it from the other way around time in general relativity is really well described we know if you move quicker time moves slower for you and other people observing you they have their own measurement of time but i'm still not clear really why what time is in quantum mechanics and how it ought i mean we we need time in there because it's what we call a unitary theory things happen a b c d but they they have to be time reversible as well.

That's another important point.

So you have to be able to go back the other way.

But we don't see those sort of processes happening on larger scales.

So I

Ben.

Is it right to say that in both quantum mechanics and general relativity,

there's nothing to stop you going back in time?

I mean, there's nothing within the actual theories.

Do you see what I mean?

Are all processes time-reversible?

No,

it's actually closed time-like geodesics are extremely...

I shouldn't have said that, it's a bit tough.

No.

In special relativity, it's

the fact that the speed of light is a constant for all observers.

Yes.

Ultimately, it is the thing that stops you being able to go back in time.

It's built into the geometry because you then would reverse causality.

But you can't bend that geometry in curved space-time.

So if you've got a powerful gravitational field, you can bend your future light cone into the past, but we think those space-time solutions are not stable.

We We don't think that it's real.

Really, we just frown upon it and hope that there is no such thing.

Since nobody's arrived from the future, is that not a good practical

tandem?

I got shouted at for saying that by a relativist because they said no, because it seems to be true that you can't go back further than the first time machine.

No, well, it depends on quantum effects.

Whose past are you going into?

What do we really mean by past, present, and future?

Because it's not clearly defined.

And

again, I've come to slowly believe for my brief foray into this area that our problems we're experiencing in finding a quantum theory of gravity lives with time.

And I think maybe

changing it or removing it, or at least some sort of alternative understanding.

Removing time.

That is what you say.

Don't say it like that, Ben.

It's not weird.

Can you do that?

Now, do you...

No, not now.

Because you can't even define what now is?

Don't remove time underworld of your own in two hours.

It'd be a disaster.

You didn't have to come up here to be insulted.

Yes, you must have heard the show before.

It's an interesting idea, though, isn't it?

That time...

The idea of removing time is the same.

But it's the most basic thing.

It's probably the thing that we find easiest to experience and describe, and yet physics has no

good description of it's different.

What better states does it?

It's a different theories, I suppose.

You've got

the second law of thermodynamics, haven't you?

You've got the...

Yes.

Yeah, someone's shouting.

This is a brilliant audience.

I was

heckled.

What about the fact that entropy always increases in a

closed system?

Aren't they lovely?

I went up to terrible.

And

I would hazard, Paul.

Hazard?

Hazard.

I would hazard that one of the very canny things about that solution in the 70s was it actually combined the second law law of thermodynamics with quantum theory and general relativity all in one go.

Because

part of the key to the puzzle was defining the entropy of a black hole, right?

Yes, it was.

And the whole area, after we realized black holes worked,

radiated, created a whole new area called black hole thermodynamics, where we have the equivalent versions of the thermodynamics of all the things we understand translated in sort of a gravity version.

But there's still problems.

Something's still wrong, because one of the big problems we have is something called the information paradox.

Is everyone here familiar with that?

Well that's safe in line.

This is like the middle of the section of that isn't it?

We'll do the popular quantum mechanics at the beginning.

We'll close with some really beautiful like kind of high cosmology but right in the middle we will go for a little bit of it.

Yeah,

let's try the B side.

So the interest

The interesting thing is is what happened so quantum mechanics says you can't lose information.

If you've got a particle, things like its charge, momentum, that can't vanish from the universe.

But if you throw it into a black hole, it's gone from the universe.

And when this radiation comes off black holes and they evaporate, there's no correlation between the stuff that fell in.

So this is a big violation of quantum mechanics.

Again, something very strange is happening that we don't understand.

Can I just check, if I do fall into a black hole, is it true I'll be spaghettified and stretched?

It depends on the size of the black hole.

And if it's rotating, if it's rotated as a big car black black hole, then you might survive the buffeting.

It'd be funny to see you spaghettified.

Well, that's what I just want to know about.

Don't mean that's not around the black hole.

Charlotte, I just loved it when you said, can I just check?

What are you

doing?

Well, you know, when you've been on a weight loss program and it has worked, and you think, well, maybe if I were taller.

What about

the idea that with Hawking radiation that

the two particles are entangled and so the one would come out of the black hole and the other would remain in.

Yes, but there's something to do with that can't be possible because

the particle can't be entangled with two things.

So, does that what does that mean for what you're saying?

Yeah,

come on, come on.

Do you want to go, Tim?

No, you go.

I think the idea, you know, so just to describe this idea, in quantum theory, so now everywhere, there are particles popping in and out of existence all the time.

And you can measure those effects, so we know that's real.

Changes the way that light, the spectrum of hydrogen atoms and things, so it's a real thing.

But on the edge of a black hole in the event horizon, you can imagine them popping into existence, and before they have time to go away and return their energy to the vacuum again, one of them falls in.

And that means that the one that's fallen in can't get back to annihilate with this one.

And that's what Hawking radiation is.

Yeah, but that idea was that they can still be entangled in some way, which means that you do something to this one, something happens to this one, even though this one has gone into a region where they can't come up with a bunch of things.

We wondered if perhaps that's how the information might be retained, but no one's really sure.

There's a recent thing called the firewall hypothesis.

I think it's rubbish.

I don't care for it at all.

And you have this idea.

We'll get letters.

What?

We'll get letters.

I'll write them back.

The firewall Easters.

I don't mind.

They're all over Twitter, the firewall Easters.

Well, they will not you've put that idea into their heads, yes.

No, I don't, because part of the problem with the firewall is that you have to suspend the equivalence principle.

And that is at the heart of general relativity, so no.

Right, that's the B-side done now.

That's the great Port Dentist House of World.

But with a fantastic guest appearance from Charlotte Church halfway through, which is what you want them to be.

Charlotte, when you're dealing with, like, what was the moment where when you were reading, well, not just the new scientists, do you have kind of stop-start moments where you get to a certain idea and it becomes so

delightful

that you go, right, this is where you stay for a while.

You're trying to be kind of, you know, Renaissance human across many ideas, but you then go this particular idea of quantum behavior, for instance.

Well, I was reading something about the idea of the big bounce as opposed to the big bang, which literally made me like clap and whoop with joy.

And it was about the idea that

you know, at the point of singularity, there is no there is zero mass but infinite energy.

And you know, it went when that happens, then you know, you've got that's the end of you know general relativity and so the idea of trying to circumvent how you get so you avoid the singularity and just reading like lots of different people's ideas of how you do that

would just just yeah it made me have a little

these are questions Tim about the the origin of the universe but which is obviously a difficult question to answer but even the origin we mentioned earlier the origin of structure in the universe which is a very interesting area of study at the moment so the so what came first?

We have this idea that there's a big bang, then the universe expands and cools.

You get atoms forming 380,000 years after the big bang, but then there's no structure for a long time.

And then, what happened?

The first stars, the first galaxies, black holes.

I think this is one of the most beautiful sort of ideas at the moment, actually.

They're not very poetic names for this period in the evolution of the universe.

So, we can see back to 380,000 years after the Big Bang.

We look at the fading glow of the Big Bang, it's the cosmic microwave background, and we can see that.

And we have spacecraft that map that, and we learn a huge amount about the universe at that time.

But after that time, as the universe is expanding, it's mostly hydrogen and some helium.

It sort of gradually gets more and more diluted, it cools down, but it's dark, there's no stars, it fades away after the brightness of the Big Bang.

And you go through this period we call the Dark Ages, where the universe is dark.

And then eventually, we think probably something like 500 million years later, the first first stars are born because the dark matter, and I know we're not allowed to talk about dark matter on this particular episode, but the dark matter sort of clumps together, and then sort of normal matter, if you like, falls into that.

And so you get these sort of dense spots where the first stars form.

When the first stars form and they start to fuse hydrogen and helium, they light up the universe.

And we call that cosmic dawn.

So you go from the dark age, the Big Bang, through the Dark Ages to cosmic dawn.

And that period,

although we know a lot about the Big Bang, we know very little.

We haven't observed the Dark Ages and cosmic dawn.

And that's what

we're building a new telescope.

The international headquarters of it is here actually at Jodderal, the Square Kilometre Array, big array of radio telescopes in South Africa and Australia.

And one of its key science aims is to observe the cosmic dawn to see the effects of the first stars lighting up the universe.

And which is so beautiful.

I'd never heard that phrase until today.

It's the first time.

So, when did that become part of cosmic dawn?

Again, that the beauty which you know can replace so much mysticism.

But just with that terminology alone, you go, That's a better narrative than my previous Odin-based one.

But we do think now, so is it widely accepted that stars form before galaxies?

We do think the galaxies come after, which is a very counterintuitive idea.

Yeah, yeah, no, so but of course, we haven't observed it.

So, we have supercomputers, we put in all the physics we think we understand.

So,

obviously, clearly, we've heard there's lots we don't, but

we do already understand a lot.

We put that all in the computer, we churn the computer through, we make a model of a big chunk of the universe, and we see what happens in the computer simulation.

And yeah, that's what pops out.

These stars are formed, these galaxies sort of structure together, you create this large-scale cosmic web, it's called.

It's like a if you have a bubble bath and you look at the form and you see the bubbles, the sort of interfaces between the bubbles are where the galaxies and the stars form, with these big voids between them.

We can see that directly.

So we have the simulations, but we haven't got the observations of that period.

And of course, you know, we shouldn't just believe theorists.

We should make observations and see whether the universe is really like that.

I mean, it's a vast universe that we look out to.

I wanted to go back, actually, Ben, because you wrote a book recently on life in this vast context.

It must be the case there's life somewhere.

But if we talk about civilization, the question really, I know Frank Drake

defined civilization as something capable of building a radio telescope.

That was his definition, in the sense that at least you could communicate.

So, what was your feeling?

What position did you come to on the likelihood of us making contact with these telescopes, seeing another civilization?

Well, I think a bit like you, I feel that

microbial life, bacterial life, that seems to kick-start itself.

If life on Earth is anything to go by, and finally

it's all we do have to go by at the moment, if that's any guide, it seems like that happened pretty quickly on Earth and it seems like that's almost a property, I mean to quote you, your ancestors are rock.

You know,

it's quite possibly volcanic vents on the seafloor of the very early Earth that produced the first cells.

It feels like that process, the harnessing of

everyday chemical reactions

into a life form happens almost on a continuum from as soon as you create a rocky planet planet with

tectonic activity you start to get that basic kind of life.

The real question and it's very very hard to answer I think with the limited amount of information we have is the leap from these almost two different kinds of very simple life that started the archaea and the bacteria here on Earth which then merged

it seems in one single event from which every other complex organism then evolved that that only only appears to have happened once.

And so, the question is: how rare is that event?

This is, in principle, an answerable question, isn't it?

And SETI,

using telescopes like the Lovell, the SETI, was frowned upon for many years, whether it was seen as a fringe activity.

Is it still?

And do you do it here?

And is it legitimate now?

So, SETI is the search for extraterrestrial intelligence, often with radio telescopes.

The problem, the reason you might say it might be frowned upon, is because you could spend your whole career

using up all the time on radio telescopes like this one, searching for signals from aliens and never getting one.

Because we have no idea if aliens exist, we have no idea if they're sending us messages.

And so that's why, in a way, it's frowned upon.

Because there's loads of other interesting stuff we could be doing with the telescopes.

But actually,

in fact, it's now part of the key science aims of many telescopes.

So we have done SETI with this telescope.

We did the thing called Project Phoenix, which we searched all the thousand nearby stars with a few telescopes around the world, including this one.

We didn't pick anything up, otherwise, it would have told you.

So,

that would and but the square kilometre array of that's one of its science aims.

It will do SETI.

So, although it'll do other stuff at the same time as well, it's got this clever system of being able to look at multiple things at once.

See, I want to ask you how putting together the images that you get from

the signals, so you know, that itself is not as you know,

that translation

from the radio signals to the image of the objects that you're talking about?

Yeah, um, so I don't know you know, in a way, you're seeing the invisible universe, so you've people are probably familiar with like thermal imaging, so infrared cameras that see at night.

So, you're seeing the infrared glow that we're all radiating now, so you can see this at night with that.

In a similar way, you're just seeing the radio glow from the sky, so it's a different type of light, so it's just at one end of the electromagnetic spectrum away from visible light, but it works in exactly the same way.

So, you could use a radio telescope like the one behind us here, and you could scan it across the sky, and you could measure the brightness of the radio sky and build up a picture that way.

Or, in fact, what we do is we connect this telescope to other ones across the country

in a big network.

We connect it across to other telescopes across the world,

they join forces, and we create a telescope the size of the planet.

Charlotte, I wanted to just how do you feel about the idea of what human reaction might be to

love because we think that we certainly, every time we've found not merely similar species, but even our own other humans, if we've considered ourselves superior to them, we have very often not treated people well.

So the idea of sentient extraterrestrial creatures that may well even be superior to us, how do you think human beings, that first announced me, do we end up with that kind of awesome Wells moment of panic during the broadcast of War of the Worlds?

Yeah, yeah, definitely.

I think everybody,

people are pretty fearful on this planet right now, and I should imagine that if you throw that into the mix, then they might completely lose their minds entirely.

I think it would be wonderful.

I read something interesting out of Harvard.

Some lady was saying that

she thought the most likely life on another planet that we'll ever discover won't be biological because there are so you know there are far fewer planets which could sustain biological life that actually what you'd be looking at is far more like super intelligent robots like AI who could live in all different sorts of terrain

who would not and the reason that they haven't contacted us is because they're so far advanced that they they really don't care they're totally disinterested in having a conversation

so we're just like a sample on a slide from pond water yeah but I quite like the idea of yeah super intelligent robots you know just patrolling the skies but I think you've got your prog rock album waiting for you there definitely

but you said that you know you think people are panicked but it could be quite a unifying thing I mean it's probably likely that we'd, it's probably a radio signal or something most likely, which means they're

untouchable, as it were.

We're not going to be able to visit these things.

Yeah, but knowing there's other

civilizations out there, do you not think that might be a unifying thing?

I think it would be completely wonderful, but I think that so many people have watched so many disaster movies.

I'm specifically thinking about Mars Attacks, which is one of my favorite films ever.

I think

the idea of knowing that something else existed and then that that tantalizing thing of not necessarily being able to know anything more or contact or do anything would just be

oh I think it would drive people mad.

There's something Bertrand Russell talked about the idea that what we almost need even if it was a fictionalized version I think this was done in the Outer Limits or Twilight Zone as well which is the idea that just out there is an extraterrestrial species that may invade at any moment and that might be the only thing that actually brings human beings together is because they think there's something else that's going to try you.

You create a bigger enemy, essentially.

Which is a bit sad in a way.

I don't want to be able to come together without having to create a new one.

It's funny, this festival is called the Blue Dot, isn't it?

Which reminds you of that famous sort of Carl Sagan passage where it was sort of seeing ourselves as a planet suspended in this

empty galaxy that sort of really

made us reimagine ourselves as a species.

I think when you you see another, you know, when we see evidence of another living species out there in the furthest reaches of a galaxy,

I think it would be a tremendously unifying thing for us for very positive reasons, because we really have to think about what our aims are, what we're here for.

And I think there's so much division in the world and in society at the moment.

And I think we could really benefit from having some sort of protocol, having some kind of UN meeting, some subcommittee, where we decide what we represent and what we would like to communicate to alien civilizations out there.

And basically tell them we want to leave Europe.

But these lines, I mean, this is, you mentioned it, and as I said, we brought it on with this, you know, the Earth is a very small stage in a vast cosmic arena.

Think of the rivers of blood spilled by all those generals and emperors so that in glory and triumph they can become the momentary masters of a fraction of a dot.

And then just said, it has been said that astronomy is a humbling and character-building experience.

There's perhaps no better demonstration of the folly of human conceits than this distant image of a tiny world.

To me it underscores our responsibility to deal more kindly with one another and to preserve and cherish the pale blue dot, the only home we've ever known.

And that to me should be

if you

if you gathered every not just every human being should read this book and every every politician if they even just just read the introduction of this book, when you do think that you know

the few people who've been able to leave the planet Earth, you know, Tim Peeps and Chris Hadfields and you know, Gene Cernan, and they have been the very few who've been able to see the whole of the planet Earth in their field of vision and the way that has changed them.

It's a fascinating thing.

Well, we have a final question.

Well, yeah, we are coming towards the end.

So, the final question,

you won't have known it, this structured discussion.

It was about things that we don't know.

Oh, yeah!

But But the final question said, Ron, is if there's one thing about the universe we don't know now that we could find out,

what would it be?

For me personally, it would be a quantum theory of gravity.

How does gravity work at the quantum level?

I'm close to wanting it to be aliens, but for me, no.

It's a bit dull, sorry.

But yeah,

working quantum theory of gravity.

Tim.

Okay, we're not allowed to talk about dark energy.

No, you can.

You can,

I loved watching your page.

Okay, so the thing is, right, the really embarrassing fact is that despite all the stuff we do know, all this stuff that we're made of that we see around us now makes up about five percent of the mass-energy density of the universe.

So, five percent of the universe is the only stuff we understand,

right?

So, the rest of it is dark matter and dark energy.

We have no idea what dark matter is.

We've known about it since the 1930s.

It's stuff that has mass, it has gravity, but we don't know what it is.

We found this other thing back in 1998.

We also didn't know what it was, so we just called it after the thing we already didn't know what it was.

So we called it dark energy.

And this is the stuff that appears to be causing the expansion of the universe to accelerate.

And I think, given that that's 95% of the whole bloody universe, I think we really ought to try and understand what that stuff is.

Charlotte?

I might sort of carry on a bit from that, and this is this is complete, like this is complete chord science,

but I would like to find some link between

so the dark matter and dark energy.

And I sort of see that in a similar way to how we have literally no idea about what consciousness is as compared to how much of the rest of our mind we know about.

So I'd quite like to figure out what consciousness is and possibly make a bigger link to physics as a whole.

Why not?

You know, it's a theoretical question.

This suddenly feels because of these high stools, it does also feel like a bit of a blind date thing, where Brian's going to go, well, I'm going to go with number one, because I thought the quantum theory of gravity answered.

So, Ben, are we alone?

That's what I want to know.

Are we alone?

You know,

we could be

right here, right now, there could be messages, there could be communication from alien civilizations that we're not even aware of.

I find that just

an amazing thought and

it's been said many times before, but either possibility is incredible.

I think most famously by Arthur C.

Clarke, either we are alone or we're not.

And either is absolutely mind-blowing.

Well, we're going to bring it to a close with something we didn't even get around to talking about, which was the golden record.

And of course, now it will be a golden iPod or USB, and that would all be required.

But we were wondering what should be placed on the next golden record that will be sent on whatever might be the next Voyager.

And Charlotte came up with an idea for what song she believed should be on that record.

So

please welcome to the singing microphone I believe and also joined by her writing partner, someone who performs with a great deal, Johnny as well.

So this is Charlotte's belief of what we should place on the next Golden USB.

Sometimes I lose myself in me, lose track of time.

And I can't see the wood for the trees.

You set them alight,

building bridges as you go.

Too weak to fight you.

And I've got my personal hell to deal with.

And you say,

walk my path,

wear my shoes.

Talk like that, I'll be an angel.

And things

can only get better.

Can only get better.

Now I've found you.

You

things

can only get better,

can only get better

now.

I found you

ready

things

can only get better

now.

I found you.

Ladies and gentlemen, Charlotte Church

and Johnny that

was

held a bit like stars in your eyes because it turned out not everyone knows the song is one of the magic.

I mean these things are going to be going

to be.

I was going to say I didn't know you were going to do that.

We did keep that quite quiet.

Thank you very much Blue Dot.

We've had this the first time we've done it in the open air in a field.

And

we have been

very happy to have with us Paul Abel, Tim O'Brien, Ben Miller, Charlotte Church.

That's the final show of this series.

We'll be back at Christmas.

Thank you, Blue Dot, and goodbye.

In the Infinite Monkey Cage

Till now, nice again.

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