All language subtitles for BBC.The.Sky.at.Night.2023.Question.Time.1080p.HDTV.x265.AAC.MVGroup.org

Hello and welcome to the
British Science Festival

here at the University of Exeter.

We've got a wonderful
live studio audience.

CHEERING

We've got some pretty difficult
questions, but an out-of-this-world

panel that's going
to try and answer them.

Welcome to a very special
Question Time edition

of The Sky at Night.

Thank you very much.

Thank you very much, indeed.
Thank you very much for coming.

Thank you very much
to everybody at home.

Welcome to the show.

It's lovely to be here in Exeter.
Lovely to be in the West Country.

We've been digging around,
looking for West Country

astrophysical claims to fame,
as it were.

We've got a few good ones.

First of all, Norman Lockyer
is a name that some people may know.

Oh, wow! OK.

Norman Lockyer, who established
an observatory here in,

when was it, 1912?

By the time he moved down
here, yeah. Yeah.

In Sidmouth, which is just
down the road from here.

He is famous for discovering
a new element in the Sun,

which he called helium,

which is named after
the Greek sun god, Helios.

And this is his spectrograph.

Isn't that amazing?
It's a beautiful object.

And if you hold it up to the light,
you can actually see,

if you're careful you can see a
beautiful spectrum, it's amazing.

There you go.
I'm going to pass it to you.

We have to be very careful
because the owner of that

is somewhere in the audience
panicking right now...

I can see it!
..and will be very cross.

So there we go, Norman Lockyer.

Slightly closer to home,
the Sylvania estate,

which is on the outskirts of Exeter,
has some rather familiar road names

which I rather like.

We've got Armstrong Avenue,
which is very good.

There we go.
Neil Armstrong. There we go.

We've got Aldrin Road, which also
should be Avenue, maybe.

And we have got Collins Road,
as in Michael Collins.

But better than both of those facts
is our wonderful panel

we have with you today.

Give them a round of applause.

We're going to introduce them.

What a panel we have for you.

We have got Chris Lintott,
long-term Sky at Night anchor.

How long has it been? Too long?

20 years or so.
It'll be 20 years?

Yeah.
Crikey! There we go.

Claim-to-fames?

Too many, too many to name?

But you've recently been made the,
what is it, the 39th...?

Gresham Professor of Astronomy.

So there's Christopher Wren,
back in the distant past,

then lots of other people and,
yeah, free lectures for everybody

going back to the 16th century.

39, it's a bit of an annoying
number, though. Well...

You kind of want to be 40th.

I was thinking it's like American
presidents, so it makes me

Jimmy Carter, which
I think I'll take.

That's pretty good. Yeah!

Even more impressive than that,
though, is you've got a podcast

called Dog Stars and you've got
a rather interesting

co-host called Mr Max.
Very quickly, tell us...

Yeah, he's the brains
of the operation.

This is him planning
the next episode.

He's a rescue lurcher who likes
people and crisps and beer,

in about that order.

And we go on walks and talk
about what we can see...

Well, I go on walks and talk about
what you can see in the night sky,

and he explores in his own way,
so...

And to my left, we've got
Maggie Aderin-Pocock.

Another... You've been on
The Sky at Night since 2014.

Space scientist,
Clanger aficionado.

But, now, I think your claim
to fame is amazing.

Tell us about your claim to fame.

You've brought your claim to fame.

Yes, I have, because earlier this
year I was...

Well, I got a rather nice surprise,

and I was actually made into a
Barbie doll.

Come on!

Very...

CHEERING

That is very, very topical.

Very de rigueur.
Yes, it's a good year to...

Because they do it every year.

They choose six people
around the world.

But this year they chose me.

And, for me, it was very exciting,

but I had a fear, and my fear was

in that moment of revelation,

because they're making it
in my likeness,

and what if I didn't like it?

Well, can you just send it...?

Can you go, "No, no, no, no, no,
take it away"?

So they lifted off the cover,

and I looked at it and I thought,

"Gosh, it does look like me,
on a really good day."

LAUGHTER

And, of course, we have
Pete Lawrence at the end there.

Now, how on earth
are you going to top that?

Have they made a doll,
an Oppenheimer doll, maybe...?

Not that I'm aware of.

They should do.

People would pay money for that.
Do you think so? Yeah.

You pull the thing at the back, pull
the string and it gives you wisdom.

"It's going to be cloudy tonight."

Yeah!
LAUGHTER

Yeah, that would work.

But I think you've got some
interesting claims to fame.

I was involved with Halley's Comet.

I was going up on flights
to go and see it.

And my claim to fame is that
the destination on the airport

departure board
was the furthest ever.

It said a flight to Halley's Comet.

Did they give you air miles?

No.
Really?!

You could have cleaned up there.
Never mind.

As well as our regular
Sky at Night guests, we have two

very special guests with us.

We have got Claire Davies
from the University of Exeter.

She is an expert on the formation
of stars and planets.

And more importantly than that,
she is a football expert.

You are a football...
Oh, totally.

Just tell us about your...
You're a player and a watcher.

I don't play any more.
Don't you?

No, I got an injury
as a teenager,

so that finished.

But I'm an avid supporter.

Big supporter of the England
team, particularly?

Both men's and women's. Yeah.

So the picture behind,
I managed to get to Wembley

for the Euros final last year.

So this isn't the World Cup final?
So this is watching them lift

the trophy, although we'd waited
until after they'd lifted the trophy

to take the photo.

OK, well, what did you think
about the World Cup final this year?

Were you jumping around,
going crazy?

I had a little bit of a dilemma
this year, so my sister got married

on exactly the same day.
See, that is just...

And the ceremony was at
kick-off as well,

like, you know, phone in my pocket,
listening to it on the radio

while we're all taking the pictures.

Did you have to do any duties?
Did you have to sort of...?

I was an usher at the beginning,
so I missed the first half.

But somehow, well, I heard
Mary Earps' save.

I am amazed how that... I reckon if
you have an empty calendar

with nothing in it
and there are two dates,

gravitational forces will bring
those dates together

and they will collide.

Especially if your sister
doesn't like football. Does she not?

Oh, no, that's a nightmare.

Claire, welcome to the panel.
Thank you very much for coming.

Well, if you want the excitement
of a World Cup final,

you couldn't ask
for more than this, really.

A Sky at Night panel show.

We've also got Hannah Wakeford
with us.

She is a specialist in exoplanets.

And you have travelled a vast
distance across,

well, almost another dimension -
the University of Bristol!

And as well as exoplanets,
you're not just a scuba diver,

you're a scuba diver-instructor,
aren't you?

So you're kind of the head honcho
scuba diver. Yeah.

So I've been scuba diving
since I was a teenager.

And this is a video of me in Hawaii,
scuba diving with the manta rays,

and flying right over my head

is Big Bertha,
is her name. Nice.

She was pregnant
at the time, and

her wingspan is
bigger than mine is,

so it's pretty impressive.

See, I look at that and, you know,
someone who looks at exoplanets,

someone who explores the night sky,

there are links, aren't there,
between scuba diving and the

kind of alien worlds in the oceans?

Yeah, and I tried to take
that to the extremes.

I decided to calculate how deep
I could scuba dive in the lakes

of Titan, a moon of Saturn,
which has lakes

of ethane and methane.

The density is very different
from water, but also the gravity

of the Moon is much less.

So you can go much, much deeper
before things start changing the way

that we see it here on Earth.

And there might be some
odd things living in there.

Well, we don't even know
how deep the lakes are.

There may be some technical
challenges to this,

but we'll fix it.

Anyway, that is your panel.

Thank you.

OK.

Let us begin.

We've got some
very challenging questions.

Right, we have got a question
from Neil Gow from Exeter,

somewhere in the audience.

Neil, ask your question.

Thank you.

Does the panel think that there
might be microbial life

outside the Earth
but within the Solar System?

And if the panel thinks that's
possible, do you think there's

any biosecurity hazards
about going to try and find

those microbes and bringing them
back to Earth to study them?

That is a good question.

I should point out, actually,
that Neil is a professor

of microbiology,
so he's slightly biased.

LAUGHTER
Slightly biased about

the microbiology.
It's a great question.

Chris, what do you think?

Well, we reported on a discovery
that might be relevant to this

a few years ago where the brilliant
Jane Greaves at Cardiff

found a chemical called phosphine
in Venus's atmosphere.

And we think of Venus
as this hellish, hot place,

but up high in the atmosphere,

if you get high enough, there's
a place where it's like a balmy

Devon summer's day most of the time.
A lot like Devon, yeah.

About 15, 12 degrees,
something like that.

LAUGHTER

And Jane found the signature, and
her team found phosphine there,

and this was controversial,
because on Earth,

phosphine is made by life.

It's not made by any other process.

And so this is possibly the
signature of some quite strange

microbial life,
high in the atmosphere of Venus.

It's still very acidic,
so it'd have to be acid-resistant.

Jane got criticised
from all angles because people

didn't believe this result,

but I saw her a month or two ago
and the phosphine is real.

They've got new observations
that show that it's there.

So it's either some weird
chemistry or it's alien.

So are we still...?
Is it still unclear?

Is the jury still out, as it were?

Well, I think we can be sure
that it's there, and it seems

to change over the course
of the day.

So, on a Venusian morning,
you see lots of phosphine

and then it disappears. Because
it was quite a measured paper.

It was. They didn't say,
"We've found aliens!"

Well, exactly, yeah.
Which was very helpful.

So that's one possibility.

There's also places like the
interior of the moon Enceladus

around Saturn, or some
of Jupiter's big moons

where we've actually

launched a spacecraft called
The Juice... Yeah.

..which is a European mission
that's going to go and visit several

of these moons to really
characterise the environment.

And once you drill through the water
ice and end up in the ocean, I think

anything could be living down there.

And we'll know more
when Juice gets there.

Very quickly, Maggie,
where do you...?

Well, you've got to look at Mars.
Yeah.

I mean, Mars is a sort of
firm favourite.

And with Percy, as I call it,
Perseverance Rover

sort of trundling over,
it's in Jethro Crater.

And as it trundles around,
that is an old river bank.

But it's a great place to look
for microbial life,

or old microbial life.

So they've been probing that.

But that sort of leads on to
the idea of going to Mars

and bringing samples back to Earth.

And that throws up a whole lot
of interesting ideas,

which I think, Hannah...

There's actually an office called
the Planetary Protection Office,

which has created a policy
for what we do to protect us

from microbial life from other
parts of our Solar System,

but also to protect other parts of
our Solar System from

microbial life from Earth.

And actually, the head of
the Planetary Protection Officer

at Nasa is also a microbiologist.

So, perhaps, Neil,
you have a different career

in your future. I'm not sure we have
a European Space Agency one,

so maybe we can appoint Neil in
charge. Yeah.

But things like not going
and prodding the water

unless you've really sterilised...

We decided earlier you don't get
a hat, you get a cape for that.

In the world of, like, badass jobs,
planetary... Like, the whole planet,

I'm going to protect...

And other planets.

And the moons. Don't forget the
moons. And the moons as well.

Pete, any thoughts on this?

Well, I don't lay awake at night

worrying about invasions
from Mars, etc.

And if that did happen,
I'd be prepared anyway.

Do you have a kind of spray
by your bed? I do.

I would be hopeful there
would be microbial life... Yeah.

..and I think we do need to be
careful because it's

probably fairly well
established to a harsh environment.

Great question.
It's really fascinating.

Right, we're going to move on.

We've got a question from
Almudena Velez,

who is studying astrophysics
here in Exeter.

Why do some stars have planetary
systems around them and others not,

and do they evolve together?

That is a Claire question,
if ever there was.

That's for you.

Well, I think you know...
Isn't she a student of yours? Yeah.

Oh, that's cheating!

So, really, I should be asking her.
Yeah.

No, so stars and planets
do form together.

She's correct in her question.

So they form in large expanses
of cool gas in the spiral arms

of our galaxy, and
other galaxies as well.

And these are called
molecular clouds,

and the density in molecular clouds
is different,

depending on where you are.

And in some regions, that density
will be critical enough

that you can collapse
on the gravity.

And as that collapse is happening,

it forms a disk around
a central core.

That central core becomes your star,

and the disk is... Well,
it's interesting if you study

planet formation, less interesting
if you study star formation.

So if you study star formation,
you're likely to say the disk

just dissipates somehow.

The star continues to accrete,
and at some point, fusion ignites

in its core and it starts
burning hydrogen into helium.

But if you're interested in studying
planet formation, then the disk

is where it's at.

You want to be probing the disk,
like, full-on.

Is the planet the kind of
leftover-y bits, the kind of...?

You could say that,

it's one of the by-products of star
formation, really, not to knock you!

Yeah, so that's a
star formation answer!

I like all these wars
between astrophysicists!

I mean, the beauty of it is, star
formation is such a wonderful

process that is leading to
what we're studying with planets,

and we've seen some amazing
star-forming regions.

This is one we're looking at,
Rho Ophiuchi here.

And this is an actual photo?

This is an actual photo
taken with JWST.

So this is a brand-new image of
this region in this kind of colour

and structure that we're seeing.

And what you can see in there
are the stars themselves being born,

and around them those disks
and those, you know, leftover stuff

that makes those planets
that we love.

That's amazing.
It's a beautiful image.

Well, thank you very much for that.

Right, we're going to move on to
talk about, well, a subject that's

very close to my heart, Voyager.

We've had a few questions
about Voyager's exploration

to the edge of the Solar System,
Voyager 1 and 2 that have now

crossed over into interstellar
space, into the interstellar medium.

It's been a bit of a tumultuous
year for Voyager 2.

Voyager 2 has had a bit
of a rough time.

Yeah, just tell us what happened.

Yeah, well, see, I remember
when the Voyagers were launched

and they've been sort of...
A long time ago. But I remember!

And so they've been travelling
out in space.

They launched in 1977,
travelling out in space.

Voyager 2 was the first spacecraft
to sort of go past Uranus

and Neptune and send pictures
back, sort of see the rings

and things like that.

So it's been a fantastic journey.

But earlier this year, a signal
was sent which actually caused

the spacecraft to move off axis
by two degrees.

Now, it doesn't sound like much,

but that two degrees
makes all the difference.

So, unfortunately, when that
two-degree angle happened,

they couldn't communicate
with the spacecraft any more.

So we couldn't get signals
from the spacecraft,

we couldn't communicate
with the spacecraft.

But they came up with an ingenious
solution, and the solution was

to shout at it, to send out
a really loud signal.

So, even with the offset,
the spacecraft could hear it.

They heard it, it went back
on angle, and communication

was re-established.

Yes. But we've had this
communication virtually

all my life.

And so the fact that we almost
lost it was quite, quite upsetting.

It's more than just a spacecraft,
you know, it is imbued with

kind of our, well, culture, really.

There's so much about the Voyager
missions that are so extraordinary.

We've kind of all grown up
with the Voyager.

The Golden Disk. Yes.

We're going to come
to that in a moment.

Actually, we've got a video
question for you now.

Up in East Yorkshire, we've got
another aspiring astrophysicist.

It's Kyle Page, who has a question
about the usefulness of Voyager

following this little mishap.

Hello.

My question is related
to the Voyagers 1 and 2.

I'd like to know, as the power
slowly reduces on the spacecraft

over the next couple of years,
is it possible for the Voyager

spacecraft to use some power to turn
on their cameras, to take pictures

again to send back to us
from a great distance?

Thank you.
It's a really interesting question.

And as well as all the science
equipment on board Voyager,

there are the cameras
which have been turned off

for a long time now.
Could you turn them on?

Is there any point
in turning them on, Chris?

It would be great to have
a postcard from out there.

I'm not sure it'd be scientifically
that useful, but it'd be great

just to see the inner Solar System
and the Sun from that distance,

but we're well past the point
where we can do that.

It's like if you've ever been out
with your mobile phone on 3%, 2%,

you have to choose really carefully
what you're going to do

with those, as... The people
nodding in the audience.

I think everyone's had
this experience!

Voyager's at that point.

You turn the camera on and we
will drain the battery instantly.

So we're running a few...

They're running a few instruments,
monitoring particles, monitoring

the magnetic fields out there.

We think there's enough power,
and they're desperately finding

new ways to try and save power,

but they think it might last
another couple of years

and then it will lose even
the power to talk to us.

We've got a picture.

This is the most famous picture
in all of astrophotography, really.

This is the famous Pale Blue Dot.

In that kind of band of light
you can see, there is one tiny pixel

that is the Earth.

And Carl Sagan had to campaign
for them to turn Voyager 2 around

to take that picture.

There's a cultural significance
to see that...

What was it, "a mote in a sunbeam"

he described it as,
with it just hanging there?

And everyone who's ever
lived on that dot. Exactly.

Hannah, you've got some thoughts
on this. Yes.

So what Voyager 2 is able to
actually tell us is the bow shock

of the Solar System itself.

So the Solar System is not static.

We are moving around the galaxy,

and that motion is actually causing

this kind of wave
to be pushed around.

We've got our own massive,
system-sized cometary tail,

and Voyager 1 and 2 have allowed us
to measure the edges of this

so that we can understand more
about our position

in our galaxy and how we, as
a solar system, are moving around.

Presumably, at some point,
we're going to lose the Voyagers.

They're going to go so far away,
but we'll be able to monitor

where they are, but not... No,
it's more that they'll run out

of power to send a signal that
we can detect and to listen to us,

so they will go silent
and disappear. OK.

They'll keep on their trajectory
and they will disappear silently

into the distance. Forever?

Yeah. They will outlive us.

They will outlive the pyramids.

God, that is terrifying! You can
calculate from their trajectory

which is the next star
they're going to reach, though.

So we can see whether they're going
to get anywhere.

But...stars are very far apart.

Well, as well as cameras
on board the Voyager spacecraft,

and all the science equipment,
there were something else

that were put on board
that you may have heard of.

We've mentioned the Golden Records.

These were these time capsules.

On these records were coded music
from the people of planet Earth,

and greetings and images
and all kinds of things.

We've got a question from
Kate Morrell,

who is in our audience.

There's something
she wanted to ask us.

Where's Kate?
Hiya.

Thank you.
Oh, there you are.

Yeah, my question is, if you were
given the opportunity today

to put something on to the
Golden Records,

what would you choose?

Good question. We're going to be
very short and punchy with this,

please, because we could spend
all day talking about this.

Maggie first. What would you put
on the Golden Record?

Earth's shadow on the VLT.

At sunset, you can see... VLT being?
Very Large Telescopes. OK.

Just came back and it was...

Anyway, so you can see the sunset,

but as the Sun is setting,

you can see the shadow of the Earth
projected on to the sky.

And when we were at the VLT,
you could actually see the mountain

we were on projected on to the sky
as a lump on the sort of

the trajectory on the sort of
topography of Earth. It was amazing.

Hannah, what would you put
on the Golden Record, if you could?

I'm putting things like Toy Story,
Finding Nemo, Wall-E. Nice!

I'm putting them some series
of things that they can watch,

but things that really showcase
the human emotion that's happening,

and Pixar does that best.

LAUGHTER

Others are available!
LAUGHTER

Claire, what would you put on?

Because of the evolution of rights
since the '70s,

I'd put a representation of the
LGBTQ+ community on there.

Very good. Very good. Thank you.

Pete?

I would put a very large monster
on there to show them that Earth

is not a pushover.

LAUGHTER
Nice!

Chris, very quickly? The thing
in the top right is a map showing

where we are in the galaxy,
based on pulsars.

It's quite complicated.

So, voicemail message, "If you get
this, please call us."

Yeah, "Your call is recorded
for training and quality purposes."

Actually, very quickly, there
was a very famous biologist,

Lewis Thomas was his name,

and Carl Sagan asked him
this very same question.

He said, "Well, if I could,
I would put the complete works

"of Johann Sebastian Bach on,
but that would be boasting."

LAUGHTER
So they didn't do that.

Right, we're moving on.

We have got a question
from Steven Moss, which is...

A little bit sci-fi,
a little bit like in 2001

with Arthur C Clarke's rotating
spaceship-type things.

Maggie, you build space stuff.

What do you think? Stuff, yes!

Well, it is an interesting idea
and it is a sound idea.

So centrifugal force is an apparent
force and it's actually

due to inertia.

But as... If you had a disk
that was spinning

and people were inside
this sort of annulus,

then they would feel
artificial gravity. Yeah.

Now, there was a chap
in the '70s called O'Neill,

and he came up with the idea
of making huge ones,

sort of like in these pictures.

I love it. These are...

So this is the stuff
of science fiction. Yeah.

But he was talking about having them
maybe sort of 8km in diameter

and 32km long, and housing
thousands of people.

And they could actually sort of live
on the outskirts of these sort of

giant structures
and sort of live in space.

And you could actually put these
Lagrange points where

the gravity
is sort of balanced out,

and they could just stay they're
in orbit around the Sun,

and this might be the future
for humanity.

I would totally live there, looking
at that, it looks really nice.

Looks pretty nice!

Can I say, when I'm prime minister,
I'm going to divert

all our money into building
one of those, just...

Jeff Bezos is doing this.

He's thinking about this
and he's got the money. Crikey!

It's one of those things,
that we've been talking about that

since the 1970s,
those sorts of things.

And maybe, maybe one day...
I think they solved it,

actually, on one of the
Bond movies, it was Moonraker.

Well, that's the greatest
of the Bond movies, clearly.

Roger Moore floats weightless
through one of the corridors,

goes through a door,
shuts the door, and he's got

gravity on the other side.

There we go.

I love...I love Moonraker.

While we're on the subject
of humans living in space,

I want to talk about the Moon
because there's been lots

of Moon news this year recently,
Hannah, just tell us, give us

a bit of a sort of rundown
on all things lunar.

Yeah, the Moon's really kind of
come back into vogue, I think,

when it comes to landing...

Has it ever been out of vogue,
the Moon?

So we hadn't gone to the Moon...

And I'm saying "we", I mean,
you know, humanity and people,

sending probes
for a really, really long time.

There's been this big gap in lunar
exploration, and we're starting

to see, like, a revamping of that.

And that kind of starts
with the Artemis programme

from Nasa, which is going to be
sending the first woman

to the Moon, which is going
to be excellent.

It's me!

It's going to be Maggie!
LAUGHTER

She would absolutely love that.

So they've actually done a flight
already which didn't have a crew

on it, but it flew around the Moon.

And the next test of the Artemis
programme is to send a crewed

mission to the Moon itself,
which would be really amazing.

But recently we just saw the
Indian lander at the South Pole

of the Moon. You can see it here.
The Moon is incredibly self-similar.

The closer you get, the more kind of
those holes start showing up.

It's an incredibly difficult place
to land, and there's been a number

of failures from other people
trying to land on it.

But we've got two more that are
heading to the Moon now.

We've got a Chinese mission
which is planning to do

a sample return.

So they're going to get a sample
from the Moon and return that

to Earth in 2026.

And then we've also got a Japanese
mission which is going to put

a lander on the Moon, and that's
going to be exploring

some of the surface. Are they
aiming for the South Pole?

I mean, South Pole, important
because water, we think,

is there, is that the kind of...?

Yeah, there's water mixed up
with the... Yeah.

..so don't think you can go and
scoop out some lunar water.

Damn it! You could go
scuba diving on the Moon!

You can probably make
rocket fuel for it.

I should say, there's obviously
European involvement as well.

So ISA is involved in the Artemis
programme and maybe putting a clone

of the International Space Station
in orbit around the Moon,

to act as a base.

We're also doing GPS for the Moon
because all of these landers

need to know where they are
and how to navigate.

But there's a whole host of things
because the Moon is not

a nice, smooth surface.

There are caves on the Moon,
there are ancient lava tubes

that people are planning to send
rovers to explore the old lava tubes

on the Moon.

So there is a whole
under-surface world up there

that we need to explore.

This is you and your
scuba diving again!

They're building...

They're getting...
I can't even get GPS on Earth,

or get Wi-Fi signal here.

Different budget. Yes.

Right, we're going to move on.

Actually, we'll stick with the Moon
for the moment.

We've got a question that's
been sent in from Ray Milton,

who lives in Matlock. Hi, Ray,
in lovely rural Derbyshire.

He asked...

So, Pete, this is obviously
a Pete question.

If you were standing
on the Moon's surface,

looking up in the sky where the
Earth was there, during

a total eclipse of the Sun,
the Earth would appear full

and it's really bright
and larger than the Moon.

And you'd see the shadow of the Moon
crossing the Earth's disk.

It's... The central part of that
shadow is about 100 miles across

on an average eclipse, and you'd see
a sort of area around...

You've got it up there, actually.
Yeah.

You've got an area around it
which is shaded and that's where

you'd see a partial eclipse
of the Sun if you were on the Earth.

So the Earth would look...
There we go.

That looks fantastic.

So this is from the
DSCOVR satellite.

It looks like it, yeah, yeah.

The astronauts on the space station
have reported seeing this as well.

So it's not as spectacular
as our view from Earth,

but it's pretty good.
It's quite impressive.

So, basically, if Ray was standing
on the Moon, he'd kind of see that?

Yes, he would.
Yeah, great. OK.

Supplementary question about this,

and this is what
I've been thinking about.

I mentioned Norman Lockyer
at the beginning and his discovery

of helium, looking at the Sun,
but I forgot to mention

that he did it when he was
looking at an eclipse,

and as well as eclipses being
dramatic and wonderful things for us

to look at, what interest do
scientists get from eclipses?

So, total eclipses, total
solar eclipses like the one

shown on screen,

those are one of the very few
opportunities we get

to look at the Sun's corona.

And that's what this white, wispy
area is that you're seeing

around that solar disk,
and that corona is a result

of the high magnetic field
of the Sun.

And so by looking at how the shape
of the corona changes year on year,

you can kind of study the
solar cycle through that as well.

And it was back in... I think
there's an eclipse in 1860s,

something like that, that they
finally realised that this corona

was associated with the Sun and
not with the Moon, because prior

to that there had been different
arguments for whether it was

an atmosphere of the Moon,
rather than the Sun.

And what about...? Hannah,
what about in the exoplanet world?

Are eclipses useful? Eclipses are
incredibly important for exoplanets,

and it's not total eclipses,
like we saw there,

but we're seeing here a video of
Venus passing in front of the Sun.

You can see the light dipping. Yeah.

If you look at that little graph
there on the right, it dips.

And as it gets to the edge,
the kind of light comes...

And the important thing is,
with that, what the amount

of light that we lose is the ratio
of the area of Venus

that is covering up the area
of the star.

So we can use that in exoplanets
to discover different worlds

around other distant stars.

We look at the stars themselves,
we measure the light from them,

and if a planet passes in front,
it causes this dip.

And from that dip we can work out
the size of that planet.

And if it happens again and again,

we can work out the orbit
of that planet.

So we're already starting
to learn huge amounts

about these alien systems.

And it is the most prolific way

of us discovering worlds
beyond our own.

Gosh, exoplanets.

It's this new frontier
of discovery, isn't it?

It's very, very exciting.

While we're on the subject
of exoplanets,

Matthew Stokes from
Worcestershire...

From Worcester, sorry!
..is also eagerly awaiting

exoplanet development.

He's got a very, very good question.

Or is it just ever going to be
kind of blobs in the distance?

Pete, what do you think?
Pete can do that.

Well, from the amateur perspective,
they're a bit out of reach

at the moment, but amateurs do
measure the drop in light

as an exoplanet goes
in front of its host star.

But there is a flight of fantasy
if you are an amateur astronomer,

because there are various stars
you can look at.

One, for example, is 55 Cancri,

which is indicated there.
Looks just like...

That's a massive spaceship
next to it!

Just like one of those
Star Wars...

A massive arrow next to it.

Surprising they didn't find
Pluto earlier

because it's always got
an arrow pointing to it.

It's massive, look!

Yeah, but 55 Cancri has got
five planets in orbit around it.

So when you look at this,
that sort of ordinary-looking star,

your imagination takes you
away to that solar system.

Hannah, you're the obvious
person to talk...

Come on, we need to see
features, we want to see...

We can actually get
images of exoplanets. Can we?

It's called "direct imaging",
because we have no imagination.

LAUGHTER
But what we're seeing here

is four giant Jupiter planets

orbiting around a star.

Now, their orbits are being measured
over the course of seven years here

with a telescope in Hawaii.

But their orbits actually take
hundreds of years

to get around their star.

They're very, very distant compared
to what we know in our solar system.

So, a bit fuzzy,
that's kind of what you're saying?

A little bit unclear.

If little fuzzy blobs is your
thing... You love fuzzy blobs!

..I can beat you with the fuzzy
blobs. Well, tell us.

So we've also got images
of planets forming as well.

So, hopefully, we're going to get
a picture up of a disk.

Here we go.

So this is a disk called PDS 70.
Even better than your name.

That's right.
LAUGHTER

So what are we looking at here with
this kind of doughnut ring?

This is a star with its inner disk
at the centre,

and then you have an outer disk
around the outside.

And between the inner disk
and the outer disk, that little blob

that you can see, the fuzzy blob,
is an orbiting protoplanet.

So it still has a disk
around itself,

just as we have circumstellar disk,
we also have circumplanetary disks,

and it's kind of turtles all the way
down, just to put a Terry Pratchett

reference in there. Nice. Very good.
We got there.

They're, like, nodding over there,

"Oh, yes, we got that,
we understood that reference."

But just, OK,
fuzzy blobs aside,

are we ever going to be
"Oh, look, there's a mountain."

Are we going to get to that?

We haven't got to the point where
our telescopes are good enough,

high enough resolution, or able
to get rid of the starlight.

Stars are so much brighter
than planets are,

and they get in the way.

If we could just get rid of them,
we'd be fine.

So we can't get surface features
just yet, but that is something

that is being planned right now.
What can we do?

What telescopes do we need to get
those surface features?

But we can see clouds.

So the question was asking
about clouds, and we can see

the clouds through the rotation
of the planet.

And if you've got patches
where you don't have clouds,

you can see deeper
into the atmosphere.

Then when you've got the clouds
there, and we can see that

from these worlds,
so they are fully three-dimensional

things that exist, that we can see.
Wow! That's amazing.

We've only been looking at
exoplanets for, like, 20 years

or something, 25 years,
something like... It's amazing.

Let's talk to someone
in our audience.

We've got Dani Rowan,
who's got a question.

Where's Dani? There she is.

Yeah, so given that we that we know
that there's CO2 in the Earth's

atmosphere, and that warms the
planet, does it indicate that CO2

on exoplanets are compatible
with life?

Crikey!

Hannah, again. Sorry!
This is your...

CO2 is the thing that we're just
really interested in at the moment,

but we've known that CO2 warms
the planet since the 1850s,

when Eunice Foote did experiments

using jars of CO2 gas
and normal air.

And she heated up these different
tubes and saw that CO2 absorbs

the heat better and it also releases
it slower than normal air does.

So it's a double whammy
in the heating, and that's

because it's such a large molecule
in the way that it's built.

It absorbs that infrared radiation.

So with JWST, which is an infrared
telescope, we've been able

to measure CO2 in the atmosphere
of an exoplanet.

This is WASP-39b....
That's an artist's...

An artist's impression of WASP-39b.

But we can see the spectrum
that we got, which is real data

of that planet's atmosphere,
and that massive bump that you see

there, in the yellow,

that's the carbon dioxide
in the atmosphere

absorbing that light.

But this is a gas giant.

It is 1,000 Kelvin.

It is a horrible place to go
for your holidays.

So when it comes to looking at
smaller and smaller planets,

we're looking for CO2 because it
has this big absorption signature,

but it doesn't mean life.

We can look at our own
solar system for that.

So Mars and Venus both have
atmospheres that are dominated

by CO2, but we would see them
very differently in their spectrum

because Mars has a very thin
atmosphere, whereas Venus

has a very thick atmosphere.

So the CO2 measurements
we're trying to make are to tell us

how thick the atmosphere
around rocky planets is.

And this stuff's really important

because people get obsessed
with planets that

could be homes for our kind of life.
Exactly.

People talk about the habitable
zone, the region around a star,

and we used to call it
"the Goldilocks Zone" before people

got too serious, because it's not
too hot and not too cold.

We still call it
the Goldilocks Zone!

The Goldilocks Zone. OK, on this
stage, it's the Goldilocks Zone.

But the thing is, not all planets
are equal. The atmosphere matters.

If the Earth didn't have
our atmosphere,

the place would be freezing, right?

And so we'd no longer be
in our Goldilocks Zone.

And so you have to really understand
the planet to be able to say

anything about conditions there.

And so the measurements that
Hannah and co are doing are vital

when we start to ask questions
like where could life exist,

how common are planets
that could support life,

and what's going on in these worlds?

Great. Dani, does that
answer your question?

Say yes! Thank you. Great, good.

This is one... We could talk
for hours about this,

but we have to move on.

I want to move on because I want to
talk about what an incredible year

it's been for the JWST.

Maggie, you have worked
on this great telescope.

From your point of view,
because it was expensive,

it went over budget,
it took a long time to build.

Has it paid off?

Are you are you kind of like,
"It was worth it"? Yes.

So it was horribly over budget,

it was horribly late,

and I was there in December 2021,
biting my fingernails

as it was launched.

But I think it has definitely
paid off because I think

JWST does the works.

It sort of looks at
sort of gases on Titan.

It looks at the age of the universe.

It just... It gets out there
and it just does a whole

multiplicity of things.

And just in terms of images,
do you have a highlight

of something that you've
kind of seen and you've gone,

"Wow, that's amazing!" Well,
actually, I think one of the things

that I'm really interested in
is NIRSpec, because that's

the instrument I worked on. OK.
And NIRSpec gave us...

NIRSpec is a complicated
instrument because it has this

microshutter array, so it has about
quarter of a million shutters.

So what it means is you could
actually sort of have a starfield

and look at multiple objects
at the same time and get multiple

spectra at the same time. OK.

And this gives us a better
understanding of galaxies,

star formation, all these things.

But it's also giving us an
understanding of

the age of the universe,
looking at cosmic dust.

It's giving us, just... Oh, yes,
yeah, it's just very exciting.

Basically, we like... It's good.

We think that's pretty good.

Yeah. Hannah, what...?
Do you have a JWST highlight?

I've got many...
Oh, here we go!

It is a fantastic telescope
for exoplanet science.

We're looking at the atmospheres
of these planets,

and one of the first data sets
that was shown to the world was,

in fact, a spectrum.

Rather than these beautiful
images, we take them,

we turn it into a squiggle for you.

And we put nice, big error bars

on that squiggle.

But what you're seeing here is

the atmosphere of an alien planet.

And we are looking at the evidence

for water vapour in the gas form -

this is a very hot world -

and also evidence for clouds
in that atmosphere.

And I love clouds.

This is going to be the way
we discover life beyond Earth,

a bit like Norman Lockyer
with his spectroscope,

looking at the atmosphere. If you
can find the right chemicals...

Exactly. ..and understand the
atmospheres. And understand them.

Yeah. It's all of these things
that play together that's

really important for these spectra.

Yeah, exciting stuff.

Claire, exciting world for you
in the JWST?

I've just been excited
by the star formation photos.

I mean, they're bigger scales
than I kind of look at. Yeah.

So I'm not directly involved
in JWST or anything,

but this is like the pillars
of creation. Yeah.

So on the left we have the
Hubble image, and on the right

we have the new JWST images.

And, like, the advancement in that,
the clarity and the fact

that we can probe now into the dark
features, which are containing dust,

so that's what obscures
the view.

It's a bit like having
night-vision goggles, you know,

to kind of peer
through something.

It's the same kind of effect
and it's just a wonderful kind of

demonstration of the advancement
in the technology, really.

I spent years telling people that
JWST would do interesting science,

but we shouldn't expect
the pictures to be spectacular.

How wrong you were. So I... Yeah.

I remember having that conversation
with you.

Yeah. Exactly, yeah. Sorry.

Pete, as our telescope expert,
what do you think?

I think the images are...
They're inspiring.

They're awesome and stunning.

And they must be inspiring the next
generation of space scientists

as well, surely, because
they are just incredible.

And, for me, one of the highlight
images is the shot

of the supernova recently, 1987A,

where, I mean, that went off in 1987

in the Large Magellanic Cloud,

which is 168,000 light years away.

And we've been studying how
that supernova, or after-supernova

region has been developing.

But now JWST is sending back
this amazing picture,

showing us the central region
where you've got interaction

between material, creating
these hot spots in a ring,

equatorial ring
around the explosion.

It's just stunning.

We like it.

Now, then, JWST, we have got
a question from our audience,

and it is from Hugh Taylor.

Where's Hugh? What's your question?

Hello and good evening.

Is it true that images
from James Webb

are making astronomers reassess
the age of the universe?

And if that is true, what is in
those images, and how old or young

might the universe be?
Good que...

There's been a bit of that
in the news recently, about the age

of the universe.

Yeah, JWST is surprising us in the
best way, which is that the early

universe is more interesting than
we thought it was going to be.

We've been finding, when JWST
just stares at random patches

of the sky like this, we find these
red blobs, which friends of mine

who call themselves "blobologists"
spend their lives studying,

and these are really
distant galaxies.

So the light from this one,
for example, has been travelling

towards us for something
like 95% of the time

that the universe has existed.

And so we're finding the early
universe is filled with more

young galaxies than we expected.

They're more massive
than we thought.

They have more star formation
than we thought. They may even...

There are hints that they have
bigger black holes at their centre

than we thought, and we're not
quite sure how this is happening.

So maybe we don't understand
how galaxies form.

Maybe there's something fundamental
that we don't understand.

Now, there was one news story...

There's a researcher in Canada
who said that he could solve

all of these problems if you doubled
the age of the universe.

But what his theory doesn't explain
is that all the stars

in these things are really young.

So he doesn't explain
the whole picture.

So I think the age of the universe
is still 13.8 billion years,

but it got going with a bang,
and not just the Big Bang.

Things started happening pretty
quickly. Is that going to change,

or do we think that's it?
We're not going to...?

So maybe these red things
are some bizarre nearby source.

So we're going through and tracking
them, but it's beginning to look

like there really are...there
really is too much activity

for our taste in the early universe,

and we're going to have
to change something in our theories

to fix it. Great. Thank you
very much for your question.

We've got another audience question.

We've got Peter Bishop.
Where's Peter?

Hello there. Hi.
Hi, Peter.

My question is, if you had to fund
one outer space research project,

what would it be and why?

Funding. Well, as your future
prime minister,

I've got a lot to say.
LAUGHTER

Big rotating space stations.

That's what I'm going to do.

Hannah, what do you think,

if you've got the strings
to the purse?

I want a mega
Hubble Space Telescope.

Hubble has been in orbit
for over 30 years now.

It has done amazing things
for science and it critically looks

in the ultraviolet and optical,
which JWST just does not do.

So when Hubble goes, I want
Mega Hubble, so that we can collect

all of the photons and understand
the whole comprehensive picture.

Perfect. Pete?

A huge telescope, I think,
on the far side of the Moon,

not in the central bit because you'd
have two weeks off every month,

but in one of the permanently
shadowed craters, and have it

remotely accessible from Earth

so we can all join in and
look to see what it can see.

Claire, money is no object.

If we're talking pipe dreams,
I'll go with space interferometry.

So, up your Hubble and go with
a series of them. Interferometry?

Interferometry. So it's when
you build telescopes in arrays.

So this image that
you're showing on screen,

so it's two different times
that you've taken a photo

of the same object, and this
is an inner disk of a star,

and we're seeing a possible
rotating feature.

Now, it's not sure whether this
is a planet at the moment.

It might be, but we're going
to have to follow it up.

But if we were to have a look at
sun-like stars,

we'd need much better,
bigger telescopes.

And that's only really possible
if we launch them up into space.

A lot of orange doughnut rings
have been...

There's a theme here.

It's just a nice colour scale
to be able to analyse the image

for the human eye, because if you
used, like, a rainbow colour scheme

or something,
then you pick up false things.

So it's just nice
to kind of use the orange.

I like it, I wasn't
complaining about it!

Chris, money no object,
what would you do?

Hannah's sorted Mega Hubble,

but we learned from the Hubble
generation that you need to fly

telescopes at different wavelengths.

So I will have, in addition
to a mega Hubble, let's have

a big version of Chandra, the X-ray
telescope, and let's have...

Actually JWST is only going to last
another 19 years.

20 years is not enough!

Yeah, let's have another
JWST, but bigger, please, Maggie!

LAUGHTER
OK, I'm on it, I'm on it!

Maggie?

Well, you see, I'm a lunatic...

You are a lunatic.
In the best possible sense. Yes!

In the best possible sense. Because
I'm totally in love with lunar,

and so Pete has got a telescope
on the Moon, but you want

to run it remotely, I want to go and
live on the Moon.

I want a moon base. I'll be next to
the telescope,

making sure it's working. You can
clean mine, then. Exactly!

I'll make it happen
as your prime minister.

This is all going to happen.

Right, we're going to move on,
our regular feature.

It is Pete's Star Guide.

What have we got to look forward to
in the coming months?

Right, well, I think let's start off
with the Orionid meteor shower,

which peaks on the night
of the 21st to the morning

of the 22nd of October.

And we've got an early-setting
first-quarter moon which will leave

the sky nice and dark for that.

The Orionids,

they appear to emanate from an area
very close to the star

Betelgeuse in Orion.

And if you see one, you're seeing
a tiny bit of Halley's Comet

vaporising in the atmosphere.

And so a week after that,
presumably, we have the full moon?

We do indeed, yes.

On the 28th, we've got a full moon.

And this particular full moon will
clip the Earth's shadow in space,

creating a partial eclipse.

Now, that peaks at

around 21.15, 21.14 BST,

and you'll get about 12%
of the Moon's diameter covered

by the Earth's shadow.

So it's not a massive one, but
it's still worth looking out for.

And, of course, you've got Jupiter
nearby when that's happening,

and Jupiter will reach opposition
when it's in the opposite part

of the sky to the Sun
on the 3rd of November,

and it's an amazing planet.

At that time, that's when it will
be at its brightest and best.

But if you have a telescope
in the UK, Jupiter is getting

really high up, so you'll get
exceptional views of it from now,

through to the end of the year.

And as we get close to the end of
the year, actually, I want to give

a shoutout to the Geminid meteor
shower, which is arguably...

No, it's not arguably, it is

the best meteor shower of the year!

He's committed. Yes.
He's committed to this.

And that peaks on the night

of the 13th of December,

into the morning of

the 14th of December.

And the mortal enemy of the

Geminid meteor shower is the Moon,

and the Moon will be out of the way.

I think those are your pictures,
aren't they? Yes, they are.

You took those. So you'll get...

This is what you've got
to look forward to.

You'll have up to 12 hours
of total darkness

to lie outside in the garden,
on a cold December night.

Heaven! And that sounds like heaven.
Oh, I can't wait for that.

CHUCKLING
I can't wait for that.

Right, we're going to move on
from things we CAN see

to things that, well,
until recently, we couldn't see,

and that is black holes.

The first image we saw was this -
it's the centre of the galaxy,

M87, which, of course,
it's another orange doughnut!

Yeah, we like them. But it caused
an absolute sensation, this one.

And then the second was the centre
of our own galaxy,

Sagittarius A star,
which was this one.

Actually, funnily enough, I read a
really good book about black holes,

it really pulled me in!
GROANING, CHUCKLING

Well, this excited everyone.

I mean, Krispy Kreme doughnuts
in the States gave everyone

in America a free orange-glazed
doughnut on the day

this was released.
Yeah. But only in America!

Like, why didn't we get...?
I know, I know!

And also, they didn't get the lumps
quite right, so theirs was smooth,

which is just wrong. Yuck!

We have a video question
all about black holes

from Jeffrey Sultoon,
who's in Cobham in Surrey.

Jeffrey.

What are the latest theories
on the behaviour of time

inside a black hole?

For example, could it be
almost stationary,

or might it even
be going backwards?

Well, finally, an easy question!
LAUGHTER

OK, here's the thing.

I've never understood black holes,

and I certainly don't understand
what happens to time in black...

You just hear kind of, like, weird
stuff. So, tell us, what's going to

happen to my watch...? Let's throw
you into a black hole, Dallas,

and... OK, yes. ..magically, you're
going to survive somehow. Right.

And so Einstein told us
that gravity changes time,

or your perception of time.

So as you fall into the black hole,
you can still see us.

Even though, once you disappear
over the event horizon, we can't see

you, you can still see light
from the rest of the universe.

So you can be watching
what's happening in the rest

of the universe.

But as you get deeper into
the gravitational field,

compared to time on the outside,
for you, it will run slower.

And so you will see the rest
of the universe slowly speed up

and get faster and faster and
faster, compared to

your perception of time. Will there
be lots of kind of cartoon clocks

whizzing past...? That's right, yes.
Yes, we know that.

And those strange green lines
will appear... Yes, exactly.

..as in The Simpsons.

But, yeah, so your perception of
time slows down when you compare

to the outside world.

From our point of view,
of course, you will have vanished

over the event horizon
and we'll cease to see you.

You know, the question was right.

At some point, time essentially,
for you, will feel like

it's completely stopped.

So once you hit the very centre
of the black hole, the singularity,

you will both be
inside the black hole

but also outside the black hole,
so... I can feel it.

..we can call this Schrodinger's
black hole, and... Keep with us.

Keep talking. If you're looking at
it, you would...

Everything would have just
completely stopped.

Sh. Time has stopped.

I can feel it. Wow, that was
amazing! There you go. Simple.

I still don't understand it, though.

The thing about time is,
the way that we perceive time,

it feels like this kind of
background river

that's kind of always there.

The idea of it behaving differently
is so counterintuitive.

I mean, one of the reasons
this is a hard question is that time

is the big mystery in physics.

We know that we can't jam...

We don't know how to jam Einstein's
relativity and quantum physics,

the theory of the small, together.
And one of the reasons is

they disagree about how
to think about time.

And a black hole is a place
where you care about relativity

AND quantum physics.

And so, you know, our theories
start to creak and it becomes

very difficult to understand
this stuff.

Can I just check,
where are we with that?

Are we kind of close
to kind of unifying those two?

I think we need the right person
to have the right idea

at the right time and stand up
and say, "It's this!"

And that person is Maggie.
LAUGHTER

Actually, what I was going to say
is that although it seems like

sort of an extrapolation, you see it
in black holes and things like that,

this is sort of real life
because our GPS systems

and our satellite systems
have to be corrected

because they are next to
the large mass of Earth.

So the fact that gravity affects
time is part of our everyday lives

and we have to work with that.
The thing I still don't understand

about black holes is people always
talk about singularities and sort of

stretching spacetime
in a sort of infinite way,

but a black hole is dense,

but it's still finite
in terms of its density.

Like, could you...? Well, we don't
know. The equations break down.

So people... I think
there's a physicist's trick

where we start muttering mystical
things about infinity and, you know,

how can we comprehend that
the singularity is infinite?

And actually what that means
is we're broken

and our equations don't work any
more. So the truth is, we don't know

what the middle of a black hole
is or how it works. All right,

talking about time,
time is fast running out,

so I'm going to move on to...
It's a video question.

It's our final question.
It's from Chris Langfield in Kent.

Chris, let's have your question.

Over the years, advances
in technology and understanding

mean that many widely-held
and well-established beliefs

have turned out not to be true.

One thinks of the Martian canals,
entries in the Messier catalogue,

or even the geocentric nature
of the universe. So my question is,

what do you think is most likely to
be the next theory to be debunked,

and, given the choice,
which would you want to turn out

to have an alternative explanation?

I love that question.
Basically, what is nonsense?

What do we think is right now
that is actually a load of old...

..you-know-what? OK, let's go
Pete, first, with this one.

Well, I would like to think

that the theory that we are alone
in the universe is wrong.

And in my lifetime, I'd like to
find other civilisations there.

But as an aside to that,

we'd study stars which vary in
their output a lot, variable stars,

and it would be great if there was
a subset of those variable stars

which was due to advanced
civilisations thinking,

"Easiest
way to signal everybody else

"is to put a shield around the star
and put it in orbit."

So the star is just blinking

because it's trying to communicate
and saying, "Hello!" So, genuinely,

I don't know that you were joking,
but there's a group of people

who are planning to look
for that sort of signal. Really?

Yeah, we've even been talking about
looking whether perhaps it would

please hyper-intelligent aliens

to make stars in different
bits of the galaxy blink together.

So we should be able
to check for this. Fantastic.

So this is actually cutting-edge
research. There you go. Perfect.

Claire, what's nonsense? And what
would you like to be nonsense?

I kind of want to pick up on
something that's recently

been debunked, rather than kind of,
like, something that I want

to be debunked,
cos that feels unkind.

You're wrong!
LAUGHTER

So, following the Juno mission
to Jupiter,

using the kind of, like, gravity
detectors that that spacecraft

had on board, we were able to see
that Jupiter's core was not solid.

And we'd all kind of just assumed
that it was solid

because of how we assume
that planets form.

So they form a core
and then they accrete the gas.

So finding that out means that
our theories of planet formation,

particularly Jupiter's formation,
or maybe its evolution

after it formed, have got to change.
Great. Well, thank you for that.

Maggie, what's on your mind?
Well, I think one of the things

that comes across for me

is that I really, really, really
want to get out there into space.

And I don't want to just go locally.
I want to... I want to travel far.

But the speed of light
is a bit of...

LAUGHTER

Could you travel in Barbie form?
Actually, well, yeah,

for the trip to the Moon, I think
I'm going to send Barbie. Yeah.

And so what I would like
is Einstein's idea

that you can't travel faster
than the speed of light,

I'd like that to be debunked,
but I'm not optimistic.

Well, every kind of five minutes
or so, someone comes up

with this new theory. "Oh, we've
found some particle that travels

"faster than the speed of light..."

But there's an opt-out, because...
Here it comes.

LAUGHTER

The Aderin-Pocock drive. Yes!
LAUGHTER

Cos there's the Alcubierre drive.

So a Mexican physicist
came up with this idea

that rather than travelling...

..rather than trying to travel
faster than the speed of light,

what you can do is
you can take spacetime,

and if you want to get from A to B,

you scrunch up spacetime in front
of you, elongate it behind you,

therefore you haven't travelled
faster than the speed of light,

but you get to your destination
super quick.

Is that like a kind of wormhole? So
rather than go from there to there,

you kind of bend it round? Well,
see, that's bending space and time.

This is actually concertinaing it up
and elongating it.

So instead of, like, a worm
going through an apple,

it's the worm actually just...
Chomping its way... Too much!

Actually, yeah... Melted my brain!
Gosh, actually... Sorry!

Suddenly that analogy...
It's not working so well, is it?

But the problem is... Actually, the
mathematics has been done for this,

and it can... Well,
theoretically, it is possible,

but the problem is you need
humongous amounts of energy

to actually sort of scrunch up
spacetime in front of you

and elongate it behind you. OK.
But I'm holding my breath.

As your prime minister.

Chris, finally, what's...?

Well... What do you think?
..we've got this idea that

most of the matter in the universe
is in the form of dark matter,

which we haven't seen,

but we're pretty convinced
it's there. I would love it

if that wasn't true,
because the alternative is

that we change gravity,
we learn some new physics,

we prove Einstein's wrong.

We open a hole for Maggie to break
Einstein's rules and go faster

than the speed of light. So I'm
pretty convinced dark matter exists.

I'd love it if that wasn't true.
That would be awesome. There'd be...

There'd be some scratching heads.
Hannah, to round things off.

I'm frustrated by the fact that
we can't see the entire universe

all the way back, so I'm going
to get rid of the expansion

of the universe so that we can
see... Our observable universe

becomes the entire thing.

I like a solid, static universe
that doesn't move. I like it.

That's right. I think that's
very good. Well, that is it.

Time is weird, as we have
established, and sadly

we've run out of it.

Just, first of all, a huge round
of applause to our wonderful panel

who've answered some really
tough questions, I think.

A round of applause to our panel.
Thank you very much, indeed.

APPLAUSE

Thank you. And, of course,
for our wonderful audience,

and for our question askers
in the audience,

give yourselves
a round of applause.

Thank you.

Thank you to the British Science
Festival for having us yet again.

And thank you to you at home. Thank
you very much for your company.

It's been an absolute pleasure,
as ever.

It just remains for me
to say goodnight.