Back to Earth 2 Stargazing Live

Welcome Back To Earth, a chance to explore some issues, shows some

photographs and give a sense of what it is like working on the show.

We thought we would make this little film. I am here by the

Lovell telescope at Jodrell Bank and at the start of each day before

every show, I like to come out here and make sure everything is working

like it should be. Yeah, all good. Come with me, as I take you on an

exclusive behind-the-scenes tour of Stargazing Live. It is from here

that the movements of that amazing dish behind they are precisely

monitored. My favourite bit is all these buttons, there's loads of

buttons and you want to go like that and press them all, but you

are not allowed to do that. You would get done if you were to do

that, so I am not doing it. This is a room that is full of tellies, and

pretty soon, I'm going to be on all of them. Having that. One of the

wonders of lunchtime is when I do some shopping and get some things

to recreate the diversity of our solar system. Like Mercury would be

a tick tack, just by the sun. You have got Venus and are worth. And

next to them, Mars, a Maltese have. Jupiter is this watermelon. You

have the asteroid belt, which we are going to recreate with a bag of

rivals like that. Some hundreds of thousands, that is the galaxy. And

that is why I love lunchtime. Astronomy allows us to contemplate

profound and very big things. The depth of the universe will see its

gradual dissipation and ultimate demise, but the number of years

until this happens is a huge number. So huge, I need help to express it,

because it is 10,000 billion, billion. Billion. Billion. Billion.

Billion years. That is like loads. Cheers.

I said, the only imperfection in his impression is that his hair is

not cry enough. He needs to get a Cryer wig. You look like you, and

you look like the bass guitar as from a Beatles tribute band. It is

not a good look for you. Thank you for joining us. We have our experts,

Tim O'Brien is with us, Dr Lucy Green, Dr Andrew Pontzen, we met

briefly and did not get rid of you and we said goodbye, apologies.

Thank you for coming back, it is very kind. We always give somebody

a gift, you deserve it more than anybody. This is meteorite wine. It

is Chilean, feel free to pop the cork. During the ageing process,

they place a meatier into the cask. As Patrick Moore says, have a drink.

How has it been out in the cold? Talk amongst yourselves! They claim

it is like tasting the birth of the universe. Are you going to give it

a taste? I certainly am. Who is coldest? I am not entirely

convinced. You are an added astronomer. As it helped to have a

few experts around -- Abid astronomer? It is always a great

thing to get a great group of astronomers together and everybody

helps each other out. There is quite a nice communal field.

seems like a happy group of people. I haven't got wind, somehow. Am I

supposed to drink from the bottle? How lousy does this look? It seems

like a good time to go to a question from a 12-year-old. Great

question, 12-year-old! Sorry. It is from Alex Worthington. The question

is, could a black hole one day appear near Earth and suck us in?

No, it won't suck us in. Yes, they could appear. There is a theory

that there are things called primordial black holes, very small,

atomic black holes. It could have been around -- they could have been

around since the Big Bang. They could be small black holes around

now, floating through this room, and we would not know it. How long

would it take for them to develop into something bigger and more

dangerous? They won't. Just because it collapses and it is a black hole,

if the sun became a black hole... It would be about three kilometres.

You could squash it down and you would not notice, the earth would

continue to orbit around it. It is a misnomer that they give up

everything that is around them. the sun turned into a black hole,

it would get dark in eight minutes, we would get very cold and all die,

but we would not get sucked into it! So look on the bright side!

Tiny black holes also evaporate very quickly, it is faster for the

small black holes and the big black holes. By quickly, what do you

mean? You're putting me on the spot. Talking about fractions of a second.

People are talking about CERN creating black holes. They were mad

people! They are already watching ITV, or Big Brother. He drives them

a way! It is not mad that it could create black holes, but they would

evaporate very quickly. The sun is not going to become a black hole?

It is not massive enough, you need to be several times the mass of the

Sun to be able to end the days of the start collapsing down, with

gravity unable to stop the collapse. It would die in a much calmer, more

sedate way. Heather asks, are black holes like wormholes in Star Trek?

There is Solutions of Einstein's equations which have that property.

I think they have to spin. I think we don't know, is probably the

answer. There has been no evidence for them. We are not certain that

they really do exist? You hear them a lot in science fiction. They

might do. I don't think it is clear. If you have something that is

formed in the real universe from a star collapsing. Under those

circumstances, it seems unlikely you would end up with a 1 hole. It

is more like mathematical solutions which have these wormholes. Can we

get to Skype? I think we can get to Henry, he is six, with his mum.

Hello. What question have you got? What would happen if the sun went

to a black hole, and how do black holes what? Thank you. Nice work.

It is a brilliant question. We already spoke about what would

happen, nothing would happen, except it would go dark and we

would eventually get very cold. But the Earth and the solar system

would remain the same. But how do black holes work is a fascinating

question. The answer is that we don't know. Do you have anything to

add? I think the thing about explaining why we would not get

sucked into a black hole is, if you could get a giant pair of hands and

crush the Sandown, it would turn into a black hole but it's a mass

would not change -- the sound down. Its mass determines how we orbit

around it. We would not notice if the sun turned into a black hole, I

guess. There was a science-fiction idea that you could use the pull of

a black hole and Emmett waste into it, and that would turn the well

that it was on. Is there any way of harnessing something like that?

is not obvious. Technologically, it seems pretty unlikely. But we see

in the universe, black holes are an amazingly efficient way of its

generating energy, more efficient than stars. If you chuck some mass

into a black hole, something like 10% of E=MC squared comes back.

That is from the radiation that we see. Matt asks, what is the largest

black hole that we know of anywhere. There are several billions of times

the mass of the Sun. The Super massive black holes that we talk

about. There are ones which are like the sun collapsing, are the

Super massive black colts much greater than the... Many times

greater, you have to happen to have much more material coming in, which

is why you see them at the centre of galaxies. Do they begin as a

super massive black holes? We have an idea of how they originate but

they tend to be relatively small solar mass type black holes, it is

pretty hard to see how you get from there to super massive black holes.

Once you have the super massive million solar mass because, you can

merge those and carry on making bigger ones. But it is hard.

heard Event Horizon used. What is that? What is the difference

between that and singularity. singularity is the mathematical

description of what a black hole is. That is what the equations tell you

you get. Considering how close you have to get to be sucked in, coming

back to this idea that black holes are cosmic Hoovers, if the sun

turned into a black hole, you would not get sucked in. But you would,

if you got to the event horizon. That is the distance at which there

is the point of no return. As you get closer to an object, the

gravitational pull increases. When you get to the event horizon...

have to interrupt. We are getting loads of photographs. We are going

over to marker. This is a representation not to

scale, I hasten to add, of the observable universe you have been

sending in fantastic pictures. We have some quite incredible ones. I

start with a picture by Robert He took this using a five-inch

It is a really superb image. The second image was taken at the role

right stones, which we used in our light permission film -- pollution

from. The camera is pointed at the sky and allows the stars to trail

across the camera. This is my favourite picture, of the sun with

a jet aircraft passing just in front. It was taken with a solar

telescope, which means you can get a very good clear image of the Sun,

Apparently we are getting nothing but the mouse questioning your

hardline stance to UFOs. There is something on the Fermi Paradox

which his 4th ball and powerful. -- -- which is a thoughtful. The

question is, why are they not here? The reason is, the galaxy is sold,

there are so many star systems, that is it is difficult to

understand why there is not a civilisation somewhere that is more

advanced, such as it should have colonise the galaxy. There is

nothing in the law of physics that says, give us a million years and

we should have been able to explore the galaxy. The question is, why

don't we see these alien probes? It is difficult to explain why. My

stance... I would not be surprised at all if a UFO landed over there.

However... On people having fun and enjoying themselves... I think they

are going to appear or they are not. If they want to come and be seen,

If they want to hide, they will not mess it up a bit. They were not

abduct 150,000 American farmers, failed to wipe the memory and then

they write a book and become famous. They would not mess up in that way.

I think that aliens might be gently watching us in the same way that

David Attenborough observes penguins. I like the assumption

that the penguins do not observe David Attenborough. I don't think

the penguins stick sticks into David Attenborough. Moving on to

celestial matters. You can drink as I am asking. Do you think there

will be a time when we can see black holes? Yes, I think this is a

really interesting question. I think there may well be. There are

lots of simulations done at the moment to give us an understanding

of what we need to look for in order to be able to see these

invisible object. You can see a mission from hot material that

forms the disco around them. But if you seek no hot material, what are

you looking for? A black shadow against the starry background. The

simulations have shown us the distortions in the distribution of

stars because of the effect of the black hole. Even if the black hole

is spinning, the black shadow would change its shape and get distorted.

Theoretically we understand some of what we should be looking for,

should we get telescopes that are good enough. There is a meeting

tomorrow in the States that is to discuss the event horizon telescope.

They are looking at a network of 50 telescopes spread across the whole

planet, working together, the King at the black hole at the centre of

the Milky Way that we discussed earlier. -- looking at. We will be

looking at light wavelengths of about 1 mm. They hope to see the

shadow and directly see the black hole. We think that black holes

Bennett something, and if that is true then they can evaporate away.

There is a stream of particles. Could we be sense -- sensitive

enough to see that? I think the ones that live for very long time

scales are very cold. When they get smaller, they emit radiation and

they lose mass, they get smaller, and that process accelerated and

they get hotter and hotter. I am not sure. It is unlikely that we

could detect radiation from anything Astrophysical but

something that is really interesting is gravitational wave

detection. One way of detecting black holes is that when they are

emerging they emit gravitational waves and there are projects to try

it and detect them. Yes, we are looking for those ripples that

would spread through the university. There would be two masses around it

which could collide into one big black hole and that could happen in

the next 10 years. Could there be the faintest possibility that if

you pass through a black hole, wormhole, is somehow the men

yourself into another dimension, another time? -- used somehow e-

mailed yourself. If you look at a messy, collapsing star, complicated

astrophysics means that these nice, mathematical properties go away and

I honestly don't think we know what an astrophysical black hole is

really like. On the subject of science fiction and science fact,

that is the perfect point to go to Patrick Moore with that question.

Science fact or science-fiction? Look at this remarkable picture. It

is aerogel. Has aerogel ever been used in space? Science fact or

science-fiction? OK, the question he was asking was about aerogel.

Are you familiar with that? I am not going to say anything. I am

familiar with it. It has been used in space missions, as he said. It

can be used as a particle detector to detect radiation, where

particles can pass through the aerogel faster than light. What

exactly is it? Highly dangerous? Lovely. I have heard it described

as liquid smoke. It breaks open very easily. Very expensive. Is it

important? That is really cool. That is the other half. Would you

like to look? Has it been used in space? You have sort of answered

that question. Have I done it again? You have. It is science fact.

Is that right? Yes, this time you are right. Aerogel has been used in

space to cap to cosmic dust. It is so incredibly low density that it

picks it up. There is nothing else quite like it.

Aero gel is an incredibly low density foam and its shares for one

trait with my hand. It is hydrophobic so that because water

and your hand should not get wet. - - repels water. That is bizarre. It

is absolutely dry. Do It again! This is amazing. It is completely

impossible to wash off or remove. My hand goes into water. You cannot

feel any water. You can feel the temperature but not the winners.

And it comes out completely dry. That is how James Bond does it!

had does feel very weird. I have a feeling this stuff will be on me

forever in some shape or form. I must make a mental note not to go

to the toilet immediately after the show. If large matters are drawn to

one another, does that mean that black holes will eventually swallow

everything up? I suppose theoretically if things got close

enough to a black hole, then they could. But they don't keep on

expanding. Over time do they get larger or smaller? Event Horizon

will get larger if you have more material going into it. In the very

long term, but the evolution of the universe will be overtaken by dark

energy, or at least we think so. We don't really understand it. That

will push all of the Delic is in the universe further apart. If for

of the material can fall into the black holes, then they will be

further and further apart and there will be lots of time to radiate

radiation and evaporate. If they stop eating, they evaporate?

Presumably the scales between different galaxies are sufficient

that they will not heat up? Andrew is right. Things are not close

enough in the universe to come together but the erratic laid... --

theoretically... You have heard the boundaries of physics expressed

beautifully. We have no idea what dark energy is, it is fair to say.

It looks like 70% of the universe is taken up making the universe

expand more quickly, accelerating its expansion. It is an absolute

mystery. Black holes are a mystery. We are talking about this radiation

as though it is the fat. It is well established theoretically but we do

not know if black holes will evaporate. Do we know how we can

interact with black holes? I will pass dark energy on to the

cosmologists, but dark matter is potentially in the realm of

particle physics. The Large Hadron Collider might make super separate

particles, a whole new set, like a mirror world if you like, but

heavier than these particles. The light is one of those is predicted

to be stable and it is a candidate for dark matter. It could be that

the universe is full of super symmetric particles. We may

discover those in the coming years. Dark energy? It only behaves like

anti-gravity. It was a complete shock when it was discovered in

1998. We have been looking at the universe expanding and what we were

expecting was these galaxies being pulled back together by their

gravity. Then the expansion would be slowing down. We found that

expansion was speeding up. We did not know what that was causing that

and already we did not know what dark matter was, so we coined the

expression dark energy. Can black holes hold the dark matter?

There have been experiments to check for this with macro lenses.

If the galaxy was full of little holes, we would be able to see that

by staring at stars and seeing the twinkles. In a similar way to

seeing what the planet hunters were doing. There would be a difference

signal when you get a planet. They would twinkle because the black

hole would pass in front of the star and Paul the light around it.

That would actually make the star brighter for the moment. How are

you doing, Jon? Dark matter and dark energy sound very sinister.

is like a James Bond villain. Happy matter? Happy energy? As we saw,

far from being dangerous, dark matter is probably the reason that

we are here. Without the simulations that we have at the

moment, there would not be any energy. Given that there are so

many stars in the universe, is somebody watching, stargazing, and

looking at us? If the universe is infinite, then yes. We can only see

a little bit of the universe, which we call the observable universe. If

you imagine as here, then there is a sphere around us from which

lights have had time to reach us from the Big Bang. That is the edge

of the observable universe. Beyond that we know there is more universe

but we do not know if it goes on forever or not. If it did, there

would be more Brian Coxs. There are already two and if they stand too

close then they evaporate! We want you to go out and see what is in

the sky above you and to help you, we have made this.

Look South straight after the show tonight and hunt for the three

stars in a row that make-up Orion's belt. A little closer to the

horizon, you may be able to make out some brighter objects close

together pointing down. These make- up Orion's sword. If the sky is

dark and clear enough, in the middle of the sort you can see what

looks like a fuzzy star. This is actually the Orion nebula, an area

where new stars are forming. Still in the constellation of Orion, you

can see a star at the other end of its life cycle. In the top left

corner, the red super-giant. If you can get a good few of this star,

you can see that it does look slightly red coloured. It is in the

process of dying and one day it will explode and go supernova. If

you look back up beyond Orion, there is more to find. At the very

top of the constellation of Taurus, there is a tiny, closely packed

group of stars. It is a star cluster of known as the seven

sisters. The reason they are so close is that they all formed from

the same gas cloud. On a much larger scale, looked to the West

and you will be looking towards our nearest galaxy, Andromeda. It is

above the tops dark in the Square of Pegasus. To the naked eye, it

will look like a hazy smudge. It is actually bigger than our galaxy. If

you are lucky enough to live in a very dark area, before the moon

rises at 3am, try spotting our galaxy, the Milky Way. It is a

dense fog of stars moving North West to South East, and passing

through Casio and serious, the brightest star in this sky.

Mark has also recorded audio guides which you can download from the

website. There is so much information. How are we doing on

the planet hunting? We have had half a million analyses done, which

is unbelievable. We will keep doing it and I think we will find planets.

Half-a-million? Let's make it 1 million by the end of the show.

Have you enjoyed it? At salute you wonderful. Thank you to the

Liverpool and Macclesfield astronomy club. -- absolutely