Lost Horizons: The Big Bang

For as long as we've been able to think,

we've wondered how we got here

and some of the ideas we've come up with have been, well, remarkable.

Every civilisation and religion in history's had its own.

In one, the universe arrived after a snail's shell

mysteriously released a hen and a pigeon.

In another, a giant emerged from an enormous egg.

Today, we have the Big Bang,

the equally remarkable idea that the universe simply began from nothing.

First of all, what do we really know about the Big Bang?

I find it hard to accept the Big Bang theory.

This is the story of how the Big Bang evolved from a left-field proposition.

Two theories of how the universe itself came into being.

To an accepted explanation of how the universe began.

Only experiments can tell us what the way forward is.

We have an outrageous ambition to understand the world, how it works, that's our objective.

As told by over 50 years of BBC science.

I call it, sometimes, the greatest adventure of the human mind.

For generations, scientists, and particularly physicists like me,

have tried to understand how the world around us came into being.

In the mid 1940s, as many physicists returned

to the front line of science and began focusing once again

on the most fundamental questions. There was deep disagreement about the origin of our universe.

At the centre of this debate were two opposing theories.

The first is that the universe has always been around.

It had no beginning, it'll have no end but is pretty much the way we see it today.

It was the brainchild of Fred Hoyle, a distinguished mathematician

and cosmologist who worked here at Cambridge University.

Professor Hoyle passionately disagreed with the second idea,

that the universe somehow was created out of nothing in an almighty explosion.

But, ironically, it was he who ensured that this

everything-from-nothing idea captured the public imagination.

In 1949, he coined the term Big Bang,

originally intended as a belittling term of abuse.

The BBC presents the Nature of the Universe.

The speaker is Fred Hoyle,

a Cambridge mathematician and Fellow of St John's College.

This Big Bang assumption is much the less palatable of the two,

for it's an irrational process that can't be described in scientific terms.

On philosophical grounds too, I can't see any good reason for preferring the Big Bang idea.

Indeed, it seems to me in the philosophical sense to be a distinctly unsatisfactory notion,

since it puts the basic assumption out of sight

where it can never be challenged by direct appeal to observation.

Professor Hoyle called his own idea the Steady State Model

and at the time many cosmologists preferred it to its rival.

Hoyle passionately believed that his theory would eventually be borne out

by observation, whereas the Big Bang would, and to his mind could, not.

The truth is, at a time when computers were men with pencils

and only fruit flies and rhesus monkeys had ever been into space,

saying anything meaningful about how the universe came into being

just by looking at the stars was exceptionally difficult.

In 1929, however, a man called Hubble had looked into the night sky

with his telescope and noticed an extraordinary thing,

a remarkable observation that would precipitate

the revolutionary idea that Professor Hoyle would eventually sneeringly label the Big Bang.

What Hubble saw from his mountain top in California

was that the steady, old, dependable universe was, in fact, anything but.

Galaxies, he noted, were hurtling away from each other at alarming speeds.

On the eve of the Great Depression,

a universe in chaos was the last thing people wanted to hear about.

The reason that Hubble knew this intergalactic weirdness

was in full swing was down to some thoroughly uncontroversial physics.

Demonstrated with admirable surrealism by Horizon in 1978.

This baroque experiment was first tried by a Dutch physicist

in the flatlands of Holland, steam engine, uniform, bandsmen and all.

The schoolmasterly enthusiasts beside a canal in Kent

have repeated the experiment for us in the same way,

probably for the first time in 140 years.

Yes, half a semitone?

-Do you think?

-Yes.

-What speed do you think he was doing, 40 kilometres?

-40 kilometres.

The expert trumpeters on the train certainly held their pitch constant

at middle C, but listeners on the ground

heard the tone change as the locomotive puffed by.

It was the physicist Christian Doppler of Prague

who first pointed out 150 years ago that such a change of pitch

would be expected whenever a steady source of waves moved with respect to an observer.

Today, we call it the Doppler Shift.

Approaching - higher pitch, shorter waves.

Receding - lower pitch, longer waves.

Yes, a semitone, about a semitone.

The Doppler Shift is just about symmetrical.

Whether source or listener moves, the effect is there.

But what do trains and trumpeters have to do with galaxies?

It turns out that the Doppler Shift also applies to light.

By measuring changes in the wavelength of light emitted

from galaxies, Hubble was able to figure out that galaxies were flying away from each other.

And receding galaxies could mean only one thing.

The universe was expanding.

Hubble's expanding universe caused a stir because of what it implied.

An expanding universe means that tomorrow it'll be bigger than it is today.

This also means that yesterday it would have been smaller,

the day before smaller still,

and if you keep winding the clock back in time,

you'd eventually arrive at a moment in history

when all the stuff of the universe is clumped together in a single tiny region.

It was this idea of a single point of creation

that caused the big debate between the Big Bang believers

and people like Fred Hoyle, who were adamant that the universe is in a steady state.

In Hoyle's universe, there was no point of creation,

and all matter hadn't been produced at one moment in the past.

In fact, he believed new matter was forming all the time.

As you probably know, there are two forms of cosmology,

what has been spoken of as the Big Bang and the Steady State.

There are actually many Big Bang cosmologies

and they all have the property

that the universe is supposed to have started at a particular moment.

Do you reject this Big Bang theory, this concept of a beginning

and an evolution and a going on?

Well, I do and I always have done

for reasons that you might think are not altogether astronomical.

I've always been impressed by the view,

the views of people who argue that the plants and animals on the Earth,

all this complexity, was due to them being suddenly made in that way.

We know now since Darwin that this is completely wrong.

We had just the same story with the chemical elements.

People said, "Well, all the different elements like sodium, oxygen,

"the carbon in our bodies, and so on, had always been that way",

but we know this isn't true,

that the oxygen that you and I now are breathing

was actually made inside stars

and that the iron in our cars was made inside stars.

So that the lesson that one learns

from these cases is that one doesn't

impress on the universe its properties in the start.

Things develop out of the basic laws, the basic laws of physics,

and I believe this must be so for the universe as a whole.

Then how is it made?

Well, I don't think it was.

I think that what we can show, quite definitely,

is that individual particles have got to be made.

If I could perhaps, sort of, demonstrate the point of view

that I have, and the point of view that the other chaps have.

Suppose I draw along here a direction,

just one direction to represent space.

That's the three dimensions of space?

Yes, all in one. And this way, time.

Now, what the Big Bang people say is that the particles,

each individual particle,

is a sort of line on here and they all start at the same moment of time.

But that's to say, these are the beginning points here,

but they don't give any sort of physical description

of what causes them to begin, whereas I think one has to

give a correct mathematical physical description

of what one means by the beginning of a particle

and I think when you do that, you don't find that they all begin at the same moment.

I think you find that they are scattered with ends at different times,

that they are all mixed together. This is what, what I find.

And that when you give correct mathematical description to this,

you'll find that the universe itself didn't have to have a beginning.

Hoyle did have a point.

Nobody had ever been able to prove that the universe had a beginning,

it was a purely theoretical concept.

Galaxies flying away from each other, flying away from each other.

Beyond any radio sources that any of us knew about or even dreamed existed.

It's just flooding in at us.

But then, in 1965, the Big Bang brigade

received a big boost thanks to a curious horn-shaped antenna in New Jersey.

The horn antenna had been part of a very early satellite transmission system.

But with the rapid march of technology it soon became redundant.

That's when two young astronomers from Bell Laboratories

decided to adapt its use to study our galaxy instead.

That detector, a horn looking like an old-fashioned ear trumpet

for a hard of hearing giant, sits on its hilltop in Homedale, New Jersey.

Among all the listening ears in the world, it was this one that caught the crucial whisper back

in 1965, the lucky start towards today's cosmology.

What it sensed came from far beyond the familiar universe

of the great optical telescopes.

Centre stage, our Sun and its planets,

merely one of a myriad of stars which orbit in the Milky Way Galaxy.

Near us too, the other galaxies of our local group,

a couple of million light years away.

Plenty of other galaxies in groups and singly crowd the stage.

Homedale saw beyond all these.

Beyond even the thousand million other galaxies we can dimly detect.

Using the Homedale Horn, two radio astronomers, Robert Wilson and Arno Penzias,

with a mixture of chance and care, came upon the great discovery.

The horn is carefully designed and built to catch microwave signals.

That is, radio waves as short as the width of your hand.

OK, I'm ready at this end, go ahead.

Before Penzias and Wilson could begin with their experiments,

they had to calibrate the detector.

OK, we start 30 degrees,

all right, and we are now on the sky.

Here we had purposely picked a portion of the spectrum,

a wavelength of seven centimetres

where we expected nothing or almost nothing, no radiation at all from the sky.

Instead what we happened is that we found radiation

coming into our antenna from all directions.

It's just flooding in at us.

This was, to put it baldly, an embarrassment.

Maybe something in the Big Horn antenna was making excess noise.

Naturally, we focused first on the antenna.

Now we had some suspicion,

because the throat of the antenna came into the cab

and that was an attractive place for pigeons, who liked to stay there,

especially in the cold winter.

We didn't mind that because they flew away when we came, except that

they had coated the surface with a white sticky material

which might not only absorb radio waves but then emit radio waves,

which could be part or maybe all of our result.

When we were able to dismantle our antenna and clean these surfaces,

putting the antenna back again we found to our surprise that most of the effect was still there.

The signal remained unceasing.

Almost reluctantly, they had to recognise the signal

was coming from somewhere outside, but what was its source?

It seemed to be coming from everywhere.

So now we were stuck with the sky beyond which was not easy for us to accept,

that this radiation was coming from somewhere

in really deep cosmic space beyond any radio sources that any of us

knew about or even dreamed existed.

But, unknown to Penzias and Wilson,

a mere 30 miles away at Princeton University,

another group was dreaming about just such radio sources from deep cosmic space.

The group was led by the physicist Bob Dicke,

who was renowned for devising novel experiments

to probe the early universe.

This was all motivated by an old interest I had connected

with what were well established views

of the universe at that time, that the universe was an expanding structure,

galaxies flying away from each other, flying away from each other

ever more rapidly the farther away they were.

The implication, of course, of all this is if you simply send

time backwards, everything is closer together in the past.

So there's an idea of something blowing up or flying apart.

Dicke saw that the early universe would at least do one thing.

The fireball would be so hot that it would endow the universe

with plenty of radiation to start with.

That radiation would still be around today

and Dicke said it should be searched for.

He left Professor Jim Peebles to work out the details.

If this radiation is present,

will we be able to detect it and will we know we're detecting it

and not radiation from something else in the universe?

We know that there are many radio sources,

galaxies that are emitting radiation at longer wavelengths.

How do we know this radiation won't get in the way?

But in a twist of fate, the radiation had already been detected at Homedale.

When Arno Penzias heard about the Princeton experiment,

he picked up the phone and called Bob Dicke.

Well, Bob received the call. We heard the discussion in the background,

bits and pieces of it, couldn't imagine what was happening.

Bob came back and said, "Boys, I think we might have it."

The news was out, the Homedale whisper

was no less than an echo of the origin of the universe.

The phenomenon was considered such a significant piece of the cosmological jigsaw,

that its accidental discoverers,

Penzias and Wilson, received the Nobel Prize for physics in 1978.

Jim Peebles and Bob Dicke on the other hand,

who had correctly interpreted the Homedale Whisper

as the echo of the Big Bang, received absolutely nothing.

But it was good news for the Big Bang theory

because the Steady State idea

could offer no explanation as to where this radiation was coming from.

Not that Fred Hoyle and the devotees of the Steady State were dissuaded.

They set to work questioning whether the radiation really did come from the Big Bang.

In the beginning, I thought this was pretty bad for the theory,

when it was first discovered, but then it's been found

that straightforward sources are emitters of high frequency radio waves

and far infrared on an enormous scale,

so it's a completely open question today, I believe,

as to whether this background really comes from the general universe

or whether it comes from sources in the general manner of radio astronomy.

And Hoyle was not alone with his dislike for the Big Bang.

For myself, I find it hard to accept the Big Bang theory.

I would like to reject it.

I much prefer Mr Hoyle's more subtle Steady State,

but I have to face the facts as a working physicist.

The evidence mounts up. Experiment after experiment

suggests that the clear predictions of the most naive theory,

the Big Bang, are coming true.

The Steady State gets more complicated,

modified, difficult to check,

so I think, if the next couple of years go as these have gone,

we shall for a generation or two hold onto the most naive cosmology.

# Wouldn't it be nice if we were older?... #

While this cosmological debate was raging, the sixties were in full swing.

Mini-skirts, the Mini Minor, and, of course, the Moon landing.

Achieving the goal before this decade is out

of landing a man on the Moon and returning him safely to the Earth.

No single space project in this period will be more impressive

to mankind or more important for the long-range exploration of space,

and none will be so difficult or expensive to accomplish.

But many people wanted to know if this massive amount of cash

being spent to put men on the Moon was really worth it.

After all, what possible use

could be made of the Moon once we'd got there?

Since Kennedy made his historic speech eight years ago,

nearly 50,000 million dollars will have been spent

towards landing a man on the Moon.

This whole vast project has been pursued with a single-mindedness

normally preserved for war

and yet the real objectives behind Kennedy's momentous decision remain to most people obscure.

But the Moon does offer great opportunities for scientific experimentation,

particularly for high-powered astronomy away from the Earth's atmosphere.

When you look at the faintest objects in the universe,

the Earth's atmosphere is giving off its own light

and so as things get further and further away

and therefore fainter and fainter, you stop seeing them from the Earth.

The Moon would let you see further out in space.

That means further back in time, so you could probably distinguish

between the two theories of how the universe itself came into being.

And this is probably the most fundamental question one could ask in astronomy.

The whole question of cosmology,

perhaps the creation of the universe is the most fundamental

question man's curiosity could ever ask about his universe

and it seems to me that an astronomical base

on the Moon could give us the answer to that question.

A plaque on the lunar module reads,

"Here men from the planet Earth

"first set foot upon the Moon, July 1969 AD.

"We came in peace for all mankind."

The reason why scientists were prepared to go to such lengths

to try and settle matters once and for all,

was that although the Big Bang seemed to be winning the two horse cosmological stakes,

there were still some things the theory couldn't explain, like how galaxies formed.

And, as problems went, this was a big one.

Hoyle and the Steady State stable reckoned that the Big Bang

would have been such a powerful explosion

that it would have produced nothing but a homogenous hot fuzz.

And that's a problem.

For stars and galaxies to form

there would need to be imperfections in the amorphous soup of the Big Bang,

tiny variations, some regions that were slightly denser than others.

These slightly denser regions would gradually attract more and more matter

until eventually the first galaxies emerged.

To stand any chance of finding these tiny variations,

scientists had to go back to Penzias' and Wilson's background radiation.

If there were any imperfections in the hot fuzz of the Big Bang,

they should also be observable in the background radiation.

But the problem with the background radiation

is that its signal is incredibly faint,

impossible to accurately decipher any unevenness

through the Earth's atmosphere.

In the late 1970s,

a group of enterprising scientists thought they'd solved the problem

by borrowing a high flying U2 reconnaissance plane, legendary for its Cold War spying missions.

Now, they were able to spy on the early universe.

In 1977 and '78,

a new reconnaissance in detail was carried out by a group at Berkeley.

They few high in the air in an old U2 spy plane.

All right, tape recorder on?

Right, we're reading on scale and we're reading plus 18.

Now, turn the rotation system on.

The U2 is fitted with a pair of open receding horns.

They're small ones matched to millimetre waves.

Their task is to scan the sky, comparing one direction with another

to see if the signal shows any sign of directionality.

True heat radiation is free of all directional detail.

It is seamless and bland, uniform in every direction,

the sign of an utterly uniform fireball long ago.

The horns rotate to exchange places and cancel out any inbuilt bias.

The sky is all but black in the thin air 13 miles high,

where the U2 flies above most of the atmosphere.

Professor Richard Muller tells of his results.

On the first few flights that we had, we could begin to see

that the uniformity of the radiation wasn't perfect. There were features.

By the time we had several flights spread out over a year,

the pattern was making itself evident.

There was a most intense region.

As you look off in the sky, it's in the constellation of Leo.

And, very significantly,

the least intense region was 180 degrees away

in the constellation of Aquarius.

What's more, the variations between these regions

was very smooth and uniform.

This gave us a ready interpretation of what was causing it

and, in fact, it was not an intrinsic variation

in the background radiation itself, but was due

to the motion of the Earth through the background radiation.

Although interesting, the U2 had failed to find the predicted ripples

in the background radiation.

There was still no evidence for how galaxies

had formed out of the Big Bang.

And things were about to get even worse for the Big Bang brigade.

When massive computers arrived on the scene in the 1980s,

cosmologists had a new tool to try and understand how galaxies emerged.

But their calculations revealed something strange.

Galaxies, it seemed, could not have formed from ordinary matter alone.

Normal matter just wasn't made of the right stuff

to clump together and produce galaxies quickly enough after the Big Bang.

99% of all the material in the universe

is invisible to us.

Some dark invisible form...

Another strange type of material must have been at work as well,

but, unfortunately, it didn't seem to shine like normal matter.

Which meant nobody was able to see it.

So, imaginatively, it was called dark matter.

In short, to explain how galaxies came about, scientists had to call

on a new type of exotic material,

dense enough to help galaxies to form,

yet inconveniently invisible.

The next step was to find out what this mysterious dark matter was made of.

The favourite explanation was

that it might be made of an as yet undiscovered particle.

Very small and very difficult to detect,

which means that if you're to stand any chance of finding one,

you need to be somewhere very quiet indeed.

We're faced with the fact that the dark matter events are very rare.

We expect, in fact, only about one a day in perhaps

a kilogram of material like this.

Now, that makes life very difficult,

because at the surface of the Earth, that one a day would be swamped

by the other types of radiation which we have around us.

So the group looked for the quietest place on Earth,

and found it in Yorkshire.

But not up here, down there, 1,000 metres below the ground.

A strange place to look for the missing matter in our universe, one would think,

but if you're looking for an ultra low background environment,

this is the place to come, the deepest mine shaft in Europe.

Here, the half-mile of rock above their heads is blocking out the cosmic radiation.

We suspend our experiment in the middle of this water tank,

then we will have the ideal environment

for searching for the very rare dark matter events which we're searching for.

The results of the UK Boulby salt mine experiment should start coming through in 1993.

The cosmologists wait in suspense.

Will the elusive dark matter be found down the bottom of a mine?

The year 1993 came and went and there was still no sign of dark matter.

Science seemed to have gone as far as it possibly could in the search

for an explanation of the universe by looking into the sky.

Unfortunately, what it saw could only make sense

by invoking strange types of matter that nobody could find.

But help was at hand from an unexpected discipline -

particle physicists, who spend their lives

creating strange types of matter by smashing atoms together

and seeing what fell out of the debris.

It seems that the key to the largest thing imaginable

might just be found in the tiniest thing possible.

Matter now is much like it was at the beginning of the Big Bang.

Are you aiming to tell about particle physics?

This is just like a great exploration.

First of all, what do we realty know about the Big Bang?

We are learning more and more about the Big Bang

from astronomical observations, but, perhaps

more interesting still,

we are learning more and more about the Big Bang too from particle physics.

In fact, it isn't quite clear whether the physicists who are interested

in elementary particles are teaching the cosmologists

more at this moment or vice versa.

You see, in the first few seconds of the universe, very near its origin,

the average energy of the particles is extremely high, very, very high,

much higher than the energies of particles produced

in the biggest accelerators here on Earth, such as the one at CERN.

And in fact, the Big Bang is sometimes nicknamed, for that reason,

the poor man's accelerator.

Particle physics and cosmology was a match made in heaven.

The study of the vast cosmos and the search for the tiny

building blocks of matter turned out to be two sides of the same coin.

About 15 billion years ago, there were no stars in the sky.

There wasn't even a sky.

All that existed was the primordial fireball.

That fireball of energy condensed

into the simplest building blocks of matter at the birth of our universe.

What were those fundamental entities from which the stars and galaxies have been built?

Physicists are trying to answer that question by taking matter apart,

looking at the pieces,

in effect looking back in time at the earliest stages of creation.

And at these earliest stages of creation,

matter existed in a weird and wonderful primeval form.

I suspect at the very beginning of the Big Bang, nature was quite simple

and it was only as the incredible temperature began to cool off,

that all the rich variety of forces and particles

that we know about today began to appear.

When the universe was so extremely hot,

a curious state of affairs prevailed.

Let's see what our calculations tell us.

Right at the start of the Big Bang, there was a high degree of symmetry

among all the different kinds of force

and the different types of particles that filled the universe.

But that state of affairs lasted for only an instant.

Almost immediately, the perfect symmetry was lost.

This all happened, in perhaps, one ten thousandth of a second

after the beginning of Big Bang.

At very small scales,

matter now is much like it was at the beginning of the Big Bang.

There's a high degree of symmetry among al the kinds of forces

and the types of particles.

We've just arrived too late in the history of the universe

to see this symmetry easily so we have to try to recreate it in our laboratory,

making little bangs in our accelerators.

The protons are in the machine, we're ready at this end.

In short, particle accelerators, it was hoped,

would provide mini Big Bangs,

tiny examples of the original conditions

under which all matter, even dark matter, was formed.

I call it sometimes the greatest adventure of the human mind,

which is the discovery to penetrate as far as possible,

to understand as much as possible about this universe,

what matter is made out of, and this is just like a great exploration.

It was an exploration that required particle accelerators

able to generate energies close to those

that must have been present at the Big Bang.

So, Hans, it looks like we finally got collisions.

And this meant building giant machines.

It almost seems a paradox that the smaller the thing you're looking for,

the bigger the instrument you need.

Near Geneva, the mysteries of the atom are probed in this gigantic laboratory.

It straddles the Swiss French border.

This one sited near San Francisco is two miles long.

Even for an experimenter driving a fast car, it's a long ride,

yet the electrons that fly along

the accelerator do the journey in a hundred thousandth of a second.

The machine tortures matter.

Picture by picture, we catch glimpses of how the universe looked

a few minutes after the creation.

The particles produced in these collisions

are much too small to be seen.

Their presence is revealed only by the tracks they leave behind them

as they pass through the detecting equipment.

The way we do find out about this proton

and the first kind of experiments that we've been making,

is to tear the electron off the atom and accelerate

the proton faster and faster and let it plough into a mass of atoms,

into a piece of ordinary matter,

hoping it'll hit one of the other protons say, hydrogen gas,

and then see what happens, what comes out.

It would be like trying to find out

what a watch is made out of and how the mechanism works

by the expedient of smashing two watches together and seeing what kind of gear wheels fly out.

These patterns, the lengths and shapes of these tracks,

describe the life histories of particles.

Some of them live only a few billionths of a second

and the tracks are the only evidence of their fleeting existence.

Interpreting these pictures, deciding what they tell us about the universe,

needs colossal imagination, the finest scientific minds of our time.

These properties of atoms that we've found here

are the same we have found out as the properties of atoms on the stars.

It's the universe that we're looking at.

So, we're not just exploring a little thing

and maybe you go very deep and it looks smaller and smaller, it's only small in dimension.

As far as the universe is concerned, it's all-encompassing.

So, it's a tremendous adventure.

It's apparently important, it's the result of curiosity, it's impossible to stop.

Back at CERN in Geneva,

the particle experiments soon attracted the curiosity of the local population.

As many documentary filmmakers have come to realise over the years,

particle physics has a habit of becoming insanely complicated very quickly.

VOICES MERGE

CERN is a strange and baffling place.

Its essential events are invisible.

They take place inside stainless steel tubes or inside physicists' heads.

The physicists' work and ideas are as difficult to understand for us

as the building bricks of matter are for the physicist.

Like them, we must rely on echoes and shadows like these.

John Cherub visited CERN again for the purpose of this film.

He talks with John Bell, a CERN theoretician, about how to make a film about CERN.

Well, it seems that one of the most difficult things

we have to talk about is how actually to put across

some of the basic ideas in particle physics

that will be necessary to anyone who wants to understand what goes on here at CERN.

What sort of people are you aiming at?

-What sort of background do these people have?

-Varied.

I mean very varied indeed and for some,

continuing interest in the sciences,

sometimes a very well informed interest and sometimes not.

And are you aiming to tell about particle physics

or about particle physicists?

Mainly about particle physics,

but incidentally about particle physicists.

So then you want a sort of formal lecture or somebody...

On the contrary, no, no, no.

Somebody starts by telling people matter is composed of small pieces

and these small pieces are composed of still smaller pieces and so on.

And the atom is something that you can describe to people

because that's like the planetary system.

There is a centre and there are a number of electrons

going around this centre which is the nucleus.

And it seems to me that you can tell people that.

There's nothing strange about that except the scale,

that it is very small.

But as soon as you delve deeper into the atom, things get stranger.

So the condition for a theory in which the infinities

can be handled at all, a necessary condition

is that the coupling constant has a dimensionality which is positive or zero.

The coupling constant appears in the Lagrange,

multiplying some kind of operator.

Hidden within the maze of mathematics were descriptions

of an array of sub-atomic particles no-one had ever seen before.

To detect these particles,

scientists built increasingly bigger and better accelerators.

These are getting 100 times the energies they've got now.

But it will be exciting. There have been tremendous advances

in theoretical physics, in particle physics, since I came.

And what gradually emerged from these atom-smashing experiments

was a detailed picture of the very early universe.

By the 1980s, particle accelerators were so powerful that they allowed

scientists to catch a glimpse of what our universe looked like just moments after the Big Bang.

Although great strides had been made by the particle physicists,

the irritating fact remained that even with the mysterious dark matter

that nobody could find, the Big Bang just didn't work

without the ripples in the Penzias and Wilson cosmic background radiation,

the telltale patches of hot and cold that the U2 spy plane had failed to detect.

In a last desperate attempt to find the all-important ripples,

a satellite called COBE was going to be launched

on board a space shuttle in 1988.

But on 28th January 1986,

the entire project was thrown into jeopardy.

The Challenger disaster meant that NASA had to reassess its whole space

shuttle strategy and, before long, COBE was dropped from the programme.

The COBE team were forced to find a substitute launch vehicle,

and at last managed to get the satellite off the ground in 1989.

Three, two.

We have main engine start and lift off.

lift off of Delta 189 and the Cosmos

Observation Background Explorer. And the vehicle has cleared the tower...

And when its data eventually trickled back to Earth, there was finally cause for celebration.

This is the eve of the anniversary of COBE's launch,

the third anniversary, and we're taking time out

from the hard work to celebrate this great event.

COBE is still gathering data.

You see the unit infrared universe here with some stars

in our galaxy showing up 300,000 years after the Big Bang.

When we watched the COBE we thought it would only go maybe a year.

That was what the original plan was, but we all hoped that it would go longer.

So we're now actually in the third year and hoping

to run successfully to run to the end of the fourth year.

Their first results had been faint and difficult to interpret,

but with an analytical team that's grown to 100,

they now seem far more confident.

There's the middle of our galaxy, and there's something else here.

This part of the sky is much brighter than this part.

Much brighter means one part in a thousand to us and it's not really much.

But this is due to the motion of the Earth relative to the rest of the universe.

Now, our data processing has actually proceeded to where we can subtract this part out.

We can subtract out the emissions from our own galaxy

across the middle and we can deduce the part that is really cosmic.

The remaining tiny fluctuations compete with noise from the detector itself.

It takes time to extract a signal from the noise.

We started out at COBE knowing that nobody knew

how these giant structures and clumpiness could occur.

There's still no complete theory of how this clumpiness emerged

and what it means, but at least they do have data for theorists to work on.

This is a map of the universe as it was 300,000 years after

the primeval explosion with a few additions here.

This portion here in the middle is from our own galaxy.

Now, what we see here are hot spots, the red ones are hot and the blue ones are cold,

and those things are about a part in a hundred thousand brighter or colder than the average here.

So these spots are going to grow up to be gigantic structures,

300 million light years across in our present age.

We have seen them before they've blown up,

before they've expanded with the universe.

It was the long-awaited result.

At last the variations in the background radiation had been found,

a quarter of a century since Penzias and Wilson

had first heard the echo from the Big Bang.

But, despite COBE, Fred Hoyle did not abandon his Steady State model.

Hoyle remained violently opposed to the theory that he had inadvertently named.

He went to his grave in 2001

still believing that his theory was correct and that Big Bang was wrong.

But the evidence was now stacked up against him.

The fact that Hubble had observed galaxies hurtling away from each other,

which meant our universe was expanding.

That Penzias and Wilson had detected radiation

left over from a primordial fireball.

Main engines start, and lift off!

And that COBE had detected ripples within this cosmic radiation.

All of this has provided overwhelming evidence for a universe created by a Big Bang.

Although, one problem persists.

The wonderful dark matter, that is so handy when it comes to explaining

how galaxies work, has still not been found.

Not in the depths of a salt mine, nor in any of the existing particle accelerators.

But this may be about to change.

Very soon, the Large Hadron Collider

at CERN in Geneva will be switched on.

It's a particle accelerator capable of creating the conditions

less than a billionth of a second after the Big Bang itself.

For the first time in 13.7 billion years,

scientists will be able to see what Hoyle claimed they never could.

They will effectively be able to witness creation.

This is like a huge new microscope that will bring us

visibility to a different world.

The universe, like everybody else,

is made of pieces which need to be understood

in order to understand how the universe works.

Some of the technologies we are using did not exist

when we started actually designing these detectors.

So, just how do you go about building a Big Bang machine?

First, burrow down 100 metres,

drill through the rock until you have a 27-kilometre, circular tunnel.

Around the tunnel cast vast chambers, each the size of a cathedral.

Inside these,

engineer the most complex cameras ever made to detect particles.

Then, after nearly two decades,

you can, at last, contemplate the experiment.

The LHC will generate seven times the energy of any previous accelerator.

By doing so, it will take us closer to the Big Bang than we have ever been before.

You can feel, by walking in the corridors of CERN

and of other laboratories in the world,

that the enthusiasm is increasing again

in anticipation of what may happen.

The scale of the forces at work in this process is unprecedented,

the experiment - a step into the unknown.

Science is what we do when we don't know what we're doing.

That's a very good scene for science.

Revolutions sometimes come from the fact that you hit a wall

and you realise that you haven't understood anything.

Some believe it's the only way we can grasp the reality of our universe.

We are actually at a point where

only experiments can tell us what the way forward is.

From a leap of faith, prompted by what one man recorded

from scanning the heavens in 1929,

to teetering on the very brink of scientific fact in 2008,

the Big Bang's journey through eight decades of philosophical debate

and scientific endeavour might finally be approaching an historic denouement.

On the other hand, if the final pieces of the cosmological jigsaw

don't fall into place at the LHC,

then our journey has only just begun.

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