0:00:17 > 0:00:20For as long as we've been able to think,
0:00:20 > 0:00:22we've wondered how we got here
0:00:22 > 0:00:27and some of the ideas we've come up with have been, well, remarkable.
0:00:27 > 0:00:31Every civilisation and religion in history's had its own.
0:00:31 > 0:00:35In one, the universe arrived after a snail's shell
0:00:35 > 0:00:38mysteriously released a hen and a pigeon.
0:00:38 > 0:00:41In another, a giant emerged from an enormous egg.
0:00:41 > 0:00:44Today, we have the Big Bang,
0:00:44 > 0:00:50the equally remarkable idea that the universe simply began from nothing.
0:00:56 > 0:01:00First of all, what do we really know about the Big Bang?
0:01:00 > 0:01:03I find it hard to accept the Big Bang theory.
0:01:03 > 0:01:09This is the story of how the Big Bang evolved from a left-field proposition.
0:01:09 > 0:01:13Two theories of how the universe itself came into being.
0:01:13 > 0:01:17To an accepted explanation of how the universe began.
0:01:17 > 0:01:20Only experiments can tell us what the way forward is.
0:01:22 > 0:01:28We have an outrageous ambition to understand the world, how it works, that's our objective.
0:01:29 > 0:01:33As told by over 50 years of BBC science.
0:01:33 > 0:01:37I call it, sometimes, the greatest adventure of the human mind.
0:02:01 > 0:02:05For generations, scientists, and particularly physicists like me,
0:02:05 > 0:02:10have tried to understand how the world around us came into being.
0:02:13 > 0:02:16In the mid 1940s, as many physicists returned
0:02:16 > 0:02:21to the front line of science and began focusing once again
0:02:21 > 0:02:27on the most fundamental questions. There was deep disagreement about the origin of our universe.
0:02:30 > 0:02:36At the centre of this debate were two opposing theories.
0:02:36 > 0:02:41The first is that the universe has always been around.
0:02:41 > 0:02:46It had no beginning, it'll have no end but is pretty much the way we see it today.
0:02:46 > 0:02:50It was the brainchild of Fred Hoyle, a distinguished mathematician
0:02:50 > 0:02:54and cosmologist who worked here at Cambridge University.
0:02:54 > 0:02:58Professor Hoyle passionately disagreed with the second idea,
0:02:58 > 0:03:03that the universe somehow was created out of nothing in an almighty explosion.
0:03:04 > 0:03:07But, ironically, it was he who ensured that this
0:03:07 > 0:03:12everything-from-nothing idea captured the public imagination.
0:03:12 > 0:03:15In 1949, he coined the term Big Bang,
0:03:15 > 0:03:20originally intended as a belittling term of abuse.
0:03:31 > 0:03:34The BBC presents the Nature of the Universe.
0:03:34 > 0:03:36The speaker is Fred Hoyle,
0:03:36 > 0:03:40a Cambridge mathematician and Fellow of St John's College.
0:03:40 > 0:03:45This Big Bang assumption is much the less palatable of the two,
0:03:45 > 0:03:50for it's an irrational process that can't be described in scientific terms.
0:03:50 > 0:03:56On philosophical grounds too, I can't see any good reason for preferring the Big Bang idea.
0:03:56 > 0:04:03Indeed, it seems to me in the philosophical sense to be a distinctly unsatisfactory notion,
0:04:03 > 0:04:05since it puts the basic assumption out of sight
0:04:05 > 0:04:09where it can never be challenged by direct appeal to observation.
0:04:18 > 0:04:23Professor Hoyle called his own idea the Steady State Model
0:04:23 > 0:04:28and at the time many cosmologists preferred it to its rival.
0:04:35 > 0:04:40Hoyle passionately believed that his theory would eventually be borne out
0:04:40 > 0:04:46by observation, whereas the Big Bang would, and to his mind could, not.
0:04:46 > 0:04:51The truth is, at a time when computers were men with pencils
0:04:51 > 0:04:55and only fruit flies and rhesus monkeys had ever been into space,
0:04:55 > 0:04:59saying anything meaningful about how the universe came into being
0:04:59 > 0:05:04just by looking at the stars was exceptionally difficult.
0:05:10 > 0:05:15In 1929, however, a man called Hubble had looked into the night sky
0:05:15 > 0:05:19with his telescope and noticed an extraordinary thing,
0:05:19 > 0:05:23a remarkable observation that would precipitate
0:05:23 > 0:05:30the revolutionary idea that Professor Hoyle would eventually sneeringly label the Big Bang.
0:05:34 > 0:05:38What Hubble saw from his mountain top in California
0:05:38 > 0:05:44was that the steady, old, dependable universe was, in fact, anything but.
0:05:44 > 0:05:49Galaxies, he noted, were hurtling away from each other at alarming speeds.
0:05:51 > 0:05:53On the eve of the Great Depression,
0:05:53 > 0:05:57a universe in chaos was the last thing people wanted to hear about.
0:05:59 > 0:06:03The reason that Hubble knew this intergalactic weirdness
0:06:03 > 0:06:08was in full swing was down to some thoroughly uncontroversial physics.
0:06:11 > 0:06:17Demonstrated with admirable surrealism by Horizon in 1978.
0:06:17 > 0:06:21This baroque experiment was first tried by a Dutch physicist
0:06:21 > 0:06:25in the flatlands of Holland, steam engine, uniform, bandsmen and all.
0:06:25 > 0:06:28The schoolmasterly enthusiasts beside a canal in Kent
0:06:28 > 0:06:30have repeated the experiment for us in the same way,
0:06:30 > 0:06:33probably for the first time in 140 years.
0:07:00 > 0:07:03Yes, half a semitone?
0:07:03 > 0:07:05- Do you think?- Yes.
0:07:05 > 0:07:08- What speed do you think he was doing, 40 kilometres? - 40 kilometres.
0:07:08 > 0:07:12The expert trumpeters on the train certainly held their pitch constant
0:07:12 > 0:07:15at middle C, but listeners on the ground
0:07:15 > 0:07:20heard the tone change as the locomotive puffed by.
0:07:20 > 0:07:23It was the physicist Christian Doppler of Prague
0:07:23 > 0:07:27who first pointed out 150 years ago that such a change of pitch
0:07:27 > 0:07:32would be expected whenever a steady source of waves moved with respect to an observer.
0:07:32 > 0:07:34Today, we call it the Doppler Shift.
0:07:36 > 0:07:40Approaching - higher pitch, shorter waves.
0:07:40 > 0:07:44Receding - lower pitch, longer waves.
0:07:53 > 0:07:56Yes, a semitone, about a semitone.
0:07:56 > 0:07:59The Doppler Shift is just about symmetrical.
0:07:59 > 0:08:02Whether source or listener moves, the effect is there.
0:08:11 > 0:08:15But what do trains and trumpeters have to do with galaxies?
0:08:22 > 0:08:27It turns out that the Doppler Shift also applies to light.
0:08:38 > 0:08:42By measuring changes in the wavelength of light emitted
0:08:42 > 0:08:48from galaxies, Hubble was able to figure out that galaxies were flying away from each other.
0:08:52 > 0:08:57And receding galaxies could mean only one thing.
0:08:58 > 0:09:02The universe was expanding.
0:09:07 > 0:09:12Hubble's expanding universe caused a stir because of what it implied.
0:09:12 > 0:09:17An expanding universe means that tomorrow it'll be bigger than it is today.
0:09:17 > 0:09:21This also means that yesterday it would have been smaller,
0:09:21 > 0:09:23the day before smaller still,
0:09:23 > 0:09:26and if you keep winding the clock back in time,
0:09:26 > 0:09:28you'd eventually arrive at a moment in history
0:09:28 > 0:09:34when all the stuff of the universe is clumped together in a single tiny region.
0:09:38 > 0:09:41It was this idea of a single point of creation
0:09:41 > 0:09:45that caused the big debate between the Big Bang believers
0:09:45 > 0:09:51and people like Fred Hoyle, who were adamant that the universe is in a steady state.
0:09:54 > 0:09:58In Hoyle's universe, there was no point of creation,
0:09:58 > 0:10:01and all matter hadn't been produced at one moment in the past.
0:10:01 > 0:10:05In fact, he believed new matter was forming all the time.
0:10:05 > 0:10:11As you probably know, there are two forms of cosmology,
0:10:11 > 0:10:14what has been spoken of as the Big Bang and the Steady State.
0:10:14 > 0:10:18There are actually many Big Bang cosmologies
0:10:18 > 0:10:21and they all have the property
0:10:21 > 0:10:25that the universe is supposed to have started at a particular moment.
0:10:25 > 0:10:29Do you reject this Big Bang theory, this concept of a beginning
0:10:29 > 0:10:31and an evolution and a going on?
0:10:31 > 0:10:34Well, I do and I always have done
0:10:34 > 0:10:39for reasons that you might think are not altogether astronomical.
0:10:39 > 0:10:41I've always been impressed by the view,
0:10:41 > 0:10:46the views of people who argue that the plants and animals on the Earth,
0:10:46 > 0:10:51all this complexity, was due to them being suddenly made in that way.
0:10:51 > 0:10:54We know now since Darwin that this is completely wrong.
0:10:54 > 0:10:57We had just the same story with the chemical elements.
0:10:57 > 0:11:01People said, "Well, all the different elements like sodium, oxygen,
0:11:01 > 0:11:04"the carbon in our bodies, and so on, had always been that way",
0:11:04 > 0:11:06but we know this isn't true,
0:11:06 > 0:11:08that the oxygen that you and I now are breathing
0:11:08 > 0:11:11was actually made inside stars
0:11:11 > 0:11:15and that the iron in our cars was made inside stars.
0:11:15 > 0:11:17So that the lesson that one learns
0:11:17 > 0:11:22from these cases is that one doesn't
0:11:22 > 0:11:27impress on the universe its properties in the start.
0:11:27 > 0:11:31Things develop out of the basic laws, the basic laws of physics,
0:11:31 > 0:11:35and I believe this must be so for the universe as a whole.
0:11:35 > 0:11:37Then how is it made?
0:11:37 > 0:11:41Well, I don't think it was.
0:11:41 > 0:11:44I think that what we can show, quite definitely,
0:11:44 > 0:11:48is that individual particles have got to be made.
0:11:48 > 0:11:53If I could perhaps, sort of, demonstrate the point of view
0:11:53 > 0:11:55that I have, and the point of view that the other chaps have.
0:11:55 > 0:11:59Suppose I draw along here a direction,
0:11:59 > 0:12:02just one direction to represent space.
0:12:02 > 0:12:04That's the three dimensions of space?
0:12:04 > 0:12:07Yes, all in one. And this way, time.
0:12:08 > 0:12:12Now, what the Big Bang people say is that the particles,
0:12:12 > 0:12:14each individual particle,
0:12:14 > 0:12:20is a sort of line on here and they all start at the same moment of time.
0:12:20 > 0:12:24But that's to say, these are the beginning points here,
0:12:24 > 0:12:27but they don't give any sort of physical description
0:12:27 > 0:12:30of what causes them to begin, whereas I think one has to
0:12:30 > 0:12:33give a correct mathematical physical description
0:12:33 > 0:12:36of what one means by the beginning of a particle
0:12:36 > 0:12:40and I think when you do that, you don't find that they all begin at the same moment.
0:12:40 > 0:12:44I think you find that they are scattered with ends at different times,
0:12:44 > 0:12:47that they are all mixed together. This is what, what I find.
0:12:47 > 0:12:51And that when you give correct mathematical description to this,
0:12:51 > 0:12:55you'll find that the universe itself didn't have to have a beginning.
0:13:01 > 0:13:03Hoyle did have a point.
0:13:03 > 0:13:07Nobody had ever been able to prove that the universe had a beginning,
0:13:07 > 0:13:10it was a purely theoretical concept.
0:13:10 > 0:13:13Galaxies flying away from each other, flying away from each other.
0:13:15 > 0:13:20Beyond any radio sources that any of us knew about or even dreamed existed.
0:13:22 > 0:13:24It's just flooding in at us.
0:13:28 > 0:13:31But then, in 1965, the Big Bang brigade
0:13:31 > 0:13:37received a big boost thanks to a curious horn-shaped antenna in New Jersey.
0:13:42 > 0:13:46The horn antenna had been part of a very early satellite transmission system.
0:13:49 > 0:13:53But with the rapid march of technology it soon became redundant.
0:13:57 > 0:14:01That's when two young astronomers from Bell Laboratories
0:14:01 > 0:14:06decided to adapt its use to study our galaxy instead.
0:14:12 > 0:14:16That detector, a horn looking like an old-fashioned ear trumpet
0:14:16 > 0:14:20for a hard of hearing giant, sits on its hilltop in Homedale, New Jersey.
0:14:20 > 0:14:25Among all the listening ears in the world, it was this one that caught the crucial whisper back
0:14:25 > 0:14:30in 1965, the lucky start towards today's cosmology.
0:14:30 > 0:14:33What it sensed came from far beyond the familiar universe
0:14:33 > 0:14:36of the great optical telescopes.
0:14:36 > 0:14:39Centre stage, our Sun and its planets,
0:14:39 > 0:14:43merely one of a myriad of stars which orbit in the Milky Way Galaxy.
0:14:46 > 0:14:49Near us too, the other galaxies of our local group,
0:14:49 > 0:14:52a couple of million light years away.
0:14:57 > 0:15:00Plenty of other galaxies in groups and singly crowd the stage.
0:15:00 > 0:15:03Homedale saw beyond all these.
0:15:06 > 0:15:10Beyond even the thousand million other galaxies we can dimly detect.
0:15:11 > 0:15:15Using the Homedale Horn, two radio astronomers, Robert Wilson and Arno Penzias,
0:15:15 > 0:15:20with a mixture of chance and care, came upon the great discovery.
0:15:23 > 0:15:27The horn is carefully designed and built to catch microwave signals.
0:15:27 > 0:15:31That is, radio waves as short as the width of your hand.
0:15:33 > 0:15:36OK, I'm ready at this end, go ahead.
0:15:36 > 0:15:40Before Penzias and Wilson could begin with their experiments,
0:15:40 > 0:15:43they had to calibrate the detector.
0:15:43 > 0:15:45OK, we start 30 degrees,
0:15:45 > 0:15:48all right, and we are now on the sky.
0:15:48 > 0:15:51Here we had purposely picked a portion of the spectrum,
0:15:51 > 0:15:53a wavelength of seven centimetres
0:15:53 > 0:15:58where we expected nothing or almost nothing, no radiation at all from the sky.
0:15:58 > 0:16:02Instead what we happened is that we found radiation
0:16:02 > 0:16:05coming into our antenna from all directions.
0:16:05 > 0:16:07It's just flooding in at us.
0:16:07 > 0:16:11This was, to put it baldly, an embarrassment.
0:16:11 > 0:16:15Maybe something in the Big Horn antenna was making excess noise.
0:16:15 > 0:16:18Naturally, we focused first on the antenna.
0:16:18 > 0:16:20Now we had some suspicion,
0:16:20 > 0:16:23because the throat of the antenna came into the cab
0:16:23 > 0:16:27and that was an attractive place for pigeons, who liked to stay there,
0:16:27 > 0:16:29especially in the cold winter.
0:16:29 > 0:16:33We didn't mind that because they flew away when we came, except that
0:16:33 > 0:16:36they had coated the surface with a white sticky material
0:16:36 > 0:16:40which might not only absorb radio waves but then emit radio waves,
0:16:40 > 0:16:44which could be part or maybe all of our result.
0:16:44 > 0:16:48When we were able to dismantle our antenna and clean these surfaces,
0:16:48 > 0:16:54putting the antenna back again we found to our surprise that most of the effect was still there.
0:16:54 > 0:16:57The signal remained unceasing.
0:16:57 > 0:17:00Almost reluctantly, they had to recognise the signal
0:17:00 > 0:17:04was coming from somewhere outside, but what was its source?
0:17:04 > 0:17:06It seemed to be coming from everywhere.
0:17:06 > 0:17:12So now we were stuck with the sky beyond which was not easy for us to accept,
0:17:12 > 0:17:14that this radiation was coming from somewhere
0:17:14 > 0:17:19in really deep cosmic space beyond any radio sources that any of us
0:17:19 > 0:17:23knew about or even dreamed existed.
0:17:26 > 0:17:29But, unknown to Penzias and Wilson,
0:17:29 > 0:17:31a mere 30 miles away at Princeton University,
0:17:31 > 0:17:39another group was dreaming about just such radio sources from deep cosmic space.
0:17:41 > 0:17:44The group was led by the physicist Bob Dicke,
0:17:44 > 0:17:48who was renowned for devising novel experiments
0:17:48 > 0:17:50to probe the early universe.
0:17:57 > 0:18:03This was all motivated by an old interest I had connected
0:18:03 > 0:18:05with what were well established views
0:18:05 > 0:18:10of the universe at that time, that the universe was an expanding structure,
0:18:10 > 0:18:14galaxies flying away from each other, flying away from each other
0:18:14 > 0:18:17ever more rapidly the farther away they were.
0:18:17 > 0:18:21The implication, of course, of all this is if you simply send
0:18:21 > 0:18:24time backwards, everything is closer together in the past.
0:18:24 > 0:18:29So there's an idea of something blowing up or flying apart.
0:18:37 > 0:18:41Dicke saw that the early universe would at least do one thing.
0:18:41 > 0:18:44The fireball would be so hot that it would endow the universe
0:18:44 > 0:18:47with plenty of radiation to start with.
0:18:47 > 0:18:49That radiation would still be around today
0:18:49 > 0:18:51and Dicke said it should be searched for.
0:18:51 > 0:18:54He left Professor Jim Peebles to work out the details.
0:18:54 > 0:18:56If this radiation is present,
0:18:56 > 0:18:59will we be able to detect it and will we know we're detecting it
0:18:59 > 0:19:02and not radiation from something else in the universe?
0:19:02 > 0:19:05We know that there are many radio sources,
0:19:05 > 0:19:08galaxies that are emitting radiation at longer wavelengths.
0:19:08 > 0:19:10How do we know this radiation won't get in the way?
0:19:12 > 0:19:18But in a twist of fate, the radiation had already been detected at Homedale.
0:19:18 > 0:19:22When Arno Penzias heard about the Princeton experiment,
0:19:22 > 0:19:24he picked up the phone and called Bob Dicke.
0:19:24 > 0:19:28Well, Bob received the call. We heard the discussion in the background,
0:19:28 > 0:19:32bits and pieces of it, couldn't imagine what was happening.
0:19:32 > 0:19:35Bob came back and said, "Boys, I think we might have it."
0:19:35 > 0:19:38The news was out, the Homedale whisper
0:19:38 > 0:19:42was no less than an echo of the origin of the universe.
0:19:54 > 0:19:59The phenomenon was considered such a significant piece of the cosmological jigsaw,
0:19:59 > 0:20:02that its accidental discoverers,
0:20:02 > 0:20:07Penzias and Wilson, received the Nobel Prize for physics in 1978.
0:20:07 > 0:20:10Jim Peebles and Bob Dicke on the other hand,
0:20:10 > 0:20:13who had correctly interpreted the Homedale Whisper
0:20:13 > 0:20:18as the echo of the Big Bang, received absolutely nothing.
0:20:18 > 0:20:21But it was good news for the Big Bang theory
0:20:21 > 0:20:23because the Steady State idea
0:20:23 > 0:20:29could offer no explanation as to where this radiation was coming from.
0:20:30 > 0:20:35Not that Fred Hoyle and the devotees of the Steady State were dissuaded.
0:20:35 > 0:20:41They set to work questioning whether the radiation really did come from the Big Bang.
0:20:41 > 0:20:44In the beginning, I thought this was pretty bad for the theory,
0:20:44 > 0:20:47when it was first discovered, but then it's been found
0:20:47 > 0:20:52that straightforward sources are emitters of high frequency radio waves
0:20:52 > 0:20:54and far infrared on an enormous scale,
0:20:54 > 0:20:57so it's a completely open question today, I believe,
0:20:57 > 0:21:01as to whether this background really comes from the general universe
0:21:01 > 0:21:06or whether it comes from sources in the general manner of radio astronomy.
0:21:06 > 0:21:12And Hoyle was not alone with his dislike for the Big Bang.
0:21:12 > 0:21:15For myself, I find it hard to accept the Big Bang theory.
0:21:15 > 0:21:17I would like to reject it.
0:21:17 > 0:21:21I much prefer Mr Hoyle's more subtle Steady State,
0:21:21 > 0:21:24but I have to face the facts as a working physicist.
0:21:24 > 0:21:27The evidence mounts up. Experiment after experiment
0:21:27 > 0:21:31suggests that the clear predictions of the most naive theory,
0:21:31 > 0:21:32the Big Bang, are coming true.
0:21:32 > 0:21:35The Steady State gets more complicated,
0:21:35 > 0:21:37modified, difficult to check,
0:21:37 > 0:21:41so I think, if the next couple of years go as these have gone,
0:21:41 > 0:21:46we shall for a generation or two hold onto the most naive cosmology.
0:21:53 > 0:21:57# Wouldn't it be nice if we were older?... #
0:21:57 > 0:22:02While this cosmological debate was raging, the sixties were in full swing.
0:22:02 > 0:22:09Mini-skirts, the Mini Minor, and, of course, the Moon landing.
0:22:09 > 0:22:13Achieving the goal before this decade is out
0:22:13 > 0:22:17of landing a man on the Moon and returning him safely to the Earth.
0:22:17 > 0:22:21No single space project in this period will be more impressive
0:22:21 > 0:22:26to mankind or more important for the long-range exploration of space,
0:22:26 > 0:22:30and none will be so difficult or expensive to accomplish.
0:22:34 > 0:22:38But many people wanted to know if this massive amount of cash
0:22:38 > 0:22:42being spent to put men on the Moon was really worth it.
0:22:42 > 0:22:44After all, what possible use
0:22:44 > 0:22:47could be made of the Moon once we'd got there?
0:23:03 > 0:23:06Since Kennedy made his historic speech eight years ago,
0:23:06 > 0:23:08nearly 50,000 million dollars will have been spent
0:23:08 > 0:23:10towards landing a man on the Moon.
0:23:10 > 0:23:14This whole vast project has been pursued with a single-mindedness
0:23:14 > 0:23:16normally preserved for war
0:23:16 > 0:23:22and yet the real objectives behind Kennedy's momentous decision remain to most people obscure.
0:23:33 > 0:23:37But the Moon does offer great opportunities for scientific experimentation,
0:23:37 > 0:23:40particularly for high-powered astronomy away from the Earth's atmosphere.
0:23:40 > 0:23:44When you look at the faintest objects in the universe,
0:23:44 > 0:23:47the Earth's atmosphere is giving off its own light
0:23:47 > 0:23:49and so as things get further and further away
0:23:49 > 0:23:53and therefore fainter and fainter, you stop seeing them from the Earth.
0:23:53 > 0:23:56The Moon would let you see further out in space.
0:23:56 > 0:24:00That means further back in time, so you could probably distinguish
0:24:00 > 0:24:05between the two theories of how the universe itself came into being.
0:24:05 > 0:24:10And this is probably the most fundamental question one could ask in astronomy.
0:24:10 > 0:24:12The whole question of cosmology,
0:24:12 > 0:24:16perhaps the creation of the universe is the most fundamental
0:24:16 > 0:24:20question man's curiosity could ever ask about his universe
0:24:20 > 0:24:22and it seems to me that an astronomical base
0:24:22 > 0:24:25on the Moon could give us the answer to that question.
0:24:40 > 0:24:42A plaque on the lunar module reads,
0:24:42 > 0:24:45"Here men from the planet Earth
0:24:45 > 0:24:50"first set foot upon the Moon, July 1969 AD.
0:24:50 > 0:24:54"We came in peace for all mankind."
0:25:03 > 0:25:07The reason why scientists were prepared to go to such lengths
0:25:07 > 0:25:09to try and settle matters once and for all,
0:25:09 > 0:25:16was that although the Big Bang seemed to be winning the two horse cosmological stakes,
0:25:16 > 0:25:22there were still some things the theory couldn't explain, like how galaxies formed.
0:25:22 > 0:25:25And, as problems went, this was a big one.
0:25:31 > 0:25:35Hoyle and the Steady State stable reckoned that the Big Bang
0:25:35 > 0:25:38would have been such a powerful explosion
0:25:38 > 0:25:42that it would have produced nothing but a homogenous hot fuzz.
0:25:42 > 0:25:45And that's a problem.
0:25:45 > 0:25:47For stars and galaxies to form
0:25:47 > 0:25:52there would need to be imperfections in the amorphous soup of the Big Bang,
0:25:52 > 0:25:58tiny variations, some regions that were slightly denser than others.
0:25:58 > 0:26:02These slightly denser regions would gradually attract more and more matter
0:26:02 > 0:26:07until eventually the first galaxies emerged.
0:26:17 > 0:26:21To stand any chance of finding these tiny variations,
0:26:21 > 0:26:26scientists had to go back to Penzias' and Wilson's background radiation.
0:26:28 > 0:26:32If there were any imperfections in the hot fuzz of the Big Bang,
0:26:32 > 0:26:36they should also be observable in the background radiation.
0:26:39 > 0:26:42But the problem with the background radiation
0:26:42 > 0:26:46is that its signal is incredibly faint,
0:26:46 > 0:26:49impossible to accurately decipher any unevenness
0:26:49 > 0:26:51through the Earth's atmosphere.
0:26:53 > 0:26:54In the late 1970s,
0:26:54 > 0:26:59a group of enterprising scientists thought they'd solved the problem
0:26:59 > 0:27:07by borrowing a high flying U2 reconnaissance plane, legendary for its Cold War spying missions.
0:27:07 > 0:27:12Now, they were able to spy on the early universe.
0:27:12 > 0:27:14In 1977 and '78,
0:27:14 > 0:27:18a new reconnaissance in detail was carried out by a group at Berkeley.
0:27:18 > 0:27:21They few high in the air in an old U2 spy plane.
0:27:24 > 0:27:26All right, tape recorder on?
0:27:28 > 0:27:32Right, we're reading on scale and we're reading plus 18.
0:27:35 > 0:27:38Now, turn the rotation system on.
0:27:38 > 0:27:42The U2 is fitted with a pair of open receding horns.
0:27:42 > 0:27:45They're small ones matched to millimetre waves.
0:27:45 > 0:27:49Their task is to scan the sky, comparing one direction with another
0:27:49 > 0:27:52to see if the signal shows any sign of directionality.
0:27:52 > 0:27:56True heat radiation is free of all directional detail.
0:27:57 > 0:28:02It is seamless and bland, uniform in every direction,
0:28:02 > 0:28:06the sign of an utterly uniform fireball long ago.
0:28:06 > 0:28:12The horns rotate to exchange places and cancel out any inbuilt bias.
0:28:26 > 0:28:30The sky is all but black in the thin air 13 miles high,
0:28:30 > 0:28:33where the U2 flies above most of the atmosphere.
0:28:40 > 0:28:43Professor Richard Muller tells of his results.
0:28:43 > 0:28:46On the first few flights that we had, we could begin to see
0:28:46 > 0:28:50that the uniformity of the radiation wasn't perfect. There were features.
0:28:50 > 0:28:54By the time we had several flights spread out over a year,
0:28:54 > 0:28:56the pattern was making itself evident.
0:28:56 > 0:28:58There was a most intense region.
0:28:58 > 0:29:02As you look off in the sky, it's in the constellation of Leo.
0:29:02 > 0:29:03And, very significantly,
0:29:03 > 0:29:06the least intense region was 180 degrees away
0:29:06 > 0:29:08in the constellation of Aquarius.
0:29:08 > 0:29:11What's more, the variations between these regions
0:29:11 > 0:29:13was very smooth and uniform.
0:29:13 > 0:29:16This gave us a ready interpretation of what was causing it
0:29:16 > 0:29:19and, in fact, it was not an intrinsic variation
0:29:19 > 0:29:21in the background radiation itself, but was due
0:29:21 > 0:29:24to the motion of the Earth through the background radiation.
0:29:24 > 0:29:29Although interesting, the U2 had failed to find the predicted ripples
0:29:29 > 0:29:32in the background radiation.
0:29:32 > 0:29:36There was still no evidence for how galaxies
0:29:36 > 0:29:39had formed out of the Big Bang.
0:29:39 > 0:29:43And things were about to get even worse for the Big Bang brigade.
0:29:52 > 0:29:56When massive computers arrived on the scene in the 1980s,
0:29:56 > 0:30:02cosmologists had a new tool to try and understand how galaxies emerged.
0:30:06 > 0:30:10But their calculations revealed something strange.
0:30:10 > 0:30:17Galaxies, it seemed, could not have formed from ordinary matter alone.
0:30:17 > 0:30:20Normal matter just wasn't made of the right stuff
0:30:20 > 0:30:24to clump together and produce galaxies quickly enough after the Big Bang.
0:30:26 > 0:30:2899% of all the material in the universe
0:30:28 > 0:30:29is invisible to us.
0:30:33 > 0:30:35Some dark invisible form...
0:30:38 > 0:30:44Another strange type of material must have been at work as well,
0:30:44 > 0:30:48but, unfortunately, it didn't seem to shine like normal matter.
0:30:50 > 0:30:54Which meant nobody was able to see it.
0:30:54 > 0:30:59So, imaginatively, it was called dark matter.
0:30:59 > 0:31:05In short, to explain how galaxies came about, scientists had to call
0:31:05 > 0:31:08on a new type of exotic material,
0:31:08 > 0:31:11dense enough to help galaxies to form,
0:31:11 > 0:31:14yet inconveniently invisible.
0:31:14 > 0:31:20The next step was to find out what this mysterious dark matter was made of.
0:31:28 > 0:31:31The favourite explanation was
0:31:31 > 0:31:35that it might be made of an as yet undiscovered particle.
0:31:38 > 0:31:42Very small and very difficult to detect,
0:31:42 > 0:31:46which means that if you're to stand any chance of finding one,
0:31:46 > 0:31:49you need to be somewhere very quiet indeed.
0:31:51 > 0:31:56We're faced with the fact that the dark matter events are very rare.
0:31:56 > 0:32:00We expect, in fact, only about one a day in perhaps
0:32:00 > 0:32:03a kilogram of material like this.
0:32:03 > 0:32:05Now, that makes life very difficult,
0:32:05 > 0:32:09because at the surface of the Earth, that one a day would be swamped
0:32:09 > 0:32:13by the other types of radiation which we have around us.
0:32:21 > 0:32:24So the group looked for the quietest place on Earth,
0:32:24 > 0:32:26and found it in Yorkshire.
0:32:27 > 0:32:32But not up here, down there, 1,000 metres below the ground.
0:32:43 > 0:32:47A strange place to look for the missing matter in our universe, one would think,
0:32:47 > 0:32:51but if you're looking for an ultra low background environment,
0:32:51 > 0:32:55this is the place to come, the deepest mine shaft in Europe.
0:33:13 > 0:33:19Here, the half-mile of rock above their heads is blocking out the cosmic radiation.
0:33:19 > 0:33:22We suspend our experiment in the middle of this water tank,
0:33:22 > 0:33:24then we will have the ideal environment
0:33:24 > 0:33:29for searching for the very rare dark matter events which we're searching for.
0:33:31 > 0:33:37The results of the UK Boulby salt mine experiment should start coming through in 1993.
0:33:37 > 0:33:39The cosmologists wait in suspense.
0:33:39 > 0:33:44Will the elusive dark matter be found down the bottom of a mine?
0:33:51 > 0:33:58The year 1993 came and went and there was still no sign of dark matter.
0:34:05 > 0:34:09Science seemed to have gone as far as it possibly could in the search
0:34:09 > 0:34:14for an explanation of the universe by looking into the sky.
0:34:14 > 0:34:18Unfortunately, what it saw could only make sense
0:34:18 > 0:34:23by invoking strange types of matter that nobody could find.
0:34:23 > 0:34:27But help was at hand from an unexpected discipline -
0:34:27 > 0:34:30particle physicists, who spend their lives
0:34:30 > 0:34:34creating strange types of matter by smashing atoms together
0:34:34 > 0:34:36and seeing what fell out of the debris.
0:34:36 > 0:34:40It seems that the key to the largest thing imaginable
0:34:40 > 0:34:44might just be found in the tiniest thing possible.
0:34:51 > 0:34:55Matter now is much like it was at the beginning of the Big Bang.
0:34:56 > 0:34:58Are you aiming to tell about particle physics?
0:34:58 > 0:35:02This is just like a great exploration.
0:35:10 > 0:35:14First of all, what do we realty know about the Big Bang?
0:35:14 > 0:35:17We are learning more and more about the Big Bang
0:35:17 > 0:35:20from astronomical observations, but, perhaps
0:35:20 > 0:35:21more interesting still,
0:35:21 > 0:35:26we are learning more and more about the Big Bang too from particle physics.
0:35:26 > 0:35:30In fact, it isn't quite clear whether the physicists who are interested
0:35:30 > 0:35:34in elementary particles are teaching the cosmologists
0:35:34 > 0:35:36more at this moment or vice versa.
0:35:36 > 0:35:40You see, in the first few seconds of the universe, very near its origin,
0:35:40 > 0:35:45the average energy of the particles is extremely high, very, very high,
0:35:45 > 0:35:48much higher than the energies of particles produced
0:35:48 > 0:35:53in the biggest accelerators here on Earth, such as the one at CERN.
0:35:53 > 0:35:57And in fact, the Big Bang is sometimes nicknamed, for that reason,
0:35:57 > 0:35:59the poor man's accelerator.
0:36:03 > 0:36:08Particle physics and cosmology was a match made in heaven.
0:36:08 > 0:36:12The study of the vast cosmos and the search for the tiny
0:36:12 > 0:36:16building blocks of matter turned out to be two sides of the same coin.
0:36:24 > 0:36:28About 15 billion years ago, there were no stars in the sky.
0:36:28 > 0:36:30There wasn't even a sky.
0:36:30 > 0:36:33All that existed was the primordial fireball.
0:36:36 > 0:36:39That fireball of energy condensed
0:36:39 > 0:36:43into the simplest building blocks of matter at the birth of our universe.
0:36:49 > 0:36:54What were those fundamental entities from which the stars and galaxies have been built?
0:36:55 > 0:37:00Physicists are trying to answer that question by taking matter apart,
0:37:00 > 0:37:01looking at the pieces,
0:37:01 > 0:37:07in effect looking back in time at the earliest stages of creation.
0:37:07 > 0:37:10And at these earliest stages of creation,
0:37:10 > 0:37:15matter existed in a weird and wonderful primeval form.
0:37:15 > 0:37:20I suspect at the very beginning of the Big Bang, nature was quite simple
0:37:20 > 0:37:24and it was only as the incredible temperature began to cool off,
0:37:24 > 0:37:27that all the rich variety of forces and particles
0:37:27 > 0:37:30that we know about today began to appear.
0:37:30 > 0:37:32When the universe was so extremely hot,
0:37:32 > 0:37:35a curious state of affairs prevailed.
0:37:35 > 0:37:38Let's see what our calculations tell us.
0:37:38 > 0:37:42Right at the start of the Big Bang, there was a high degree of symmetry
0:37:42 > 0:37:44among all the different kinds of force
0:37:44 > 0:37:47and the different types of particles that filled the universe.
0:37:47 > 0:37:50But that state of affairs lasted for only an instant.
0:37:50 > 0:37:53Almost immediately, the perfect symmetry was lost.
0:37:53 > 0:37:57This all happened, in perhaps, one ten thousandth of a second
0:37:57 > 0:37:59after the beginning of Big Bang.
0:37:59 > 0:38:01At very small scales,
0:38:01 > 0:38:06matter now is much like it was at the beginning of the Big Bang.
0:38:06 > 0:38:10There's a high degree of symmetry among al the kinds of forces
0:38:10 > 0:38:12and the types of particles.
0:38:12 > 0:38:15We've just arrived too late in the history of the universe
0:38:15 > 0:38:20to see this symmetry easily so we have to try to recreate it in our laboratory,
0:38:20 > 0:38:23making little bangs in our accelerators.
0:38:30 > 0:38:36The protons are in the machine, we're ready at this end.
0:38:36 > 0:38:40In short, particle accelerators, it was hoped,
0:38:40 > 0:38:43would provide mini Big Bangs,
0:38:43 > 0:38:45tiny examples of the original conditions
0:38:45 > 0:38:50under which all matter, even dark matter, was formed.
0:38:50 > 0:38:54I call it sometimes the greatest adventure of the human mind,
0:38:54 > 0:38:57which is the discovery to penetrate as far as possible,
0:38:57 > 0:39:00to understand as much as possible about this universe,
0:39:00 > 0:39:03what matter is made out of, and this is just like a great exploration.
0:39:07 > 0:39:11It was an exploration that required particle accelerators
0:39:11 > 0:39:13able to generate energies close to those
0:39:13 > 0:39:16that must have been present at the Big Bang.
0:39:16 > 0:39:20So, Hans, it looks like we finally got collisions.
0:39:20 > 0:39:22And this meant building giant machines.
0:39:24 > 0:39:28It almost seems a paradox that the smaller the thing you're looking for,
0:39:28 > 0:39:30the bigger the instrument you need.
0:39:30 > 0:39:35Near Geneva, the mysteries of the atom are probed in this gigantic laboratory.
0:39:35 > 0:39:37It straddles the Swiss French border.
0:39:42 > 0:39:46This one sited near San Francisco is two miles long.
0:39:49 > 0:39:54Even for an experimenter driving a fast car, it's a long ride,
0:39:54 > 0:39:57yet the electrons that fly along
0:39:57 > 0:40:01the accelerator do the journey in a hundred thousandth of a second.
0:40:40 > 0:40:44The machine tortures matter.
0:40:44 > 0:40:48Picture by picture, we catch glimpses of how the universe looked
0:40:48 > 0:40:51a few minutes after the creation.
0:40:51 > 0:40:53The particles produced in these collisions
0:40:53 > 0:40:55are much too small to be seen.
0:40:55 > 0:40:58Their presence is revealed only by the tracks they leave behind them
0:40:58 > 0:41:01as they pass through the detecting equipment.
0:41:03 > 0:41:05The way we do find out about this proton
0:41:05 > 0:41:09and the first kind of experiments that we've been making,
0:41:09 > 0:41:12is to tear the electron off the atom and accelerate
0:41:12 > 0:41:15the proton faster and faster and let it plough into a mass of atoms,
0:41:15 > 0:41:17into a piece of ordinary matter,
0:41:17 > 0:41:21hoping it'll hit one of the other protons say, hydrogen gas,
0:41:21 > 0:41:24and then see what happens, what comes out.
0:41:24 > 0:41:26It would be like trying to find out
0:41:26 > 0:41:29what a watch is made out of and how the mechanism works
0:41:29 > 0:41:34by the expedient of smashing two watches together and seeing what kind of gear wheels fly out.
0:41:34 > 0:41:38These patterns, the lengths and shapes of these tracks,
0:41:38 > 0:41:41describe the life histories of particles.
0:41:41 > 0:41:44Some of them live only a few billionths of a second
0:41:44 > 0:41:48and the tracks are the only evidence of their fleeting existence.
0:41:48 > 0:41:52Interpreting these pictures, deciding what they tell us about the universe,
0:41:52 > 0:41:57needs colossal imagination, the finest scientific minds of our time.
0:41:57 > 0:42:00These properties of atoms that we've found here
0:42:00 > 0:42:03are the same we have found out as the properties of atoms on the stars.
0:42:03 > 0:42:06It's the universe that we're looking at.
0:42:06 > 0:42:08So, we're not just exploring a little thing
0:42:08 > 0:42:13and maybe you go very deep and it looks smaller and smaller, it's only small in dimension.
0:42:13 > 0:42:16As far as the universe is concerned, it's all-encompassing.
0:42:16 > 0:42:18So, it's a tremendous adventure.
0:42:18 > 0:42:23It's apparently important, it's the result of curiosity, it's impossible to stop.
0:42:28 > 0:42:29Back at CERN in Geneva,
0:42:29 > 0:42:35the particle experiments soon attracted the curiosity of the local population.
0:43:03 > 0:43:08As many documentary filmmakers have come to realise over the years,
0:43:08 > 0:43:13particle physics has a habit of becoming insanely complicated very quickly.
0:43:13 > 0:43:16VOICES MERGE
0:43:26 > 0:43:29CERN is a strange and baffling place.
0:43:29 > 0:43:32Its essential events are invisible.
0:43:35 > 0:43:42They take place inside stainless steel tubes or inside physicists' heads.
0:43:50 > 0:43:55The physicists' work and ideas are as difficult to understand for us
0:43:55 > 0:43:59as the building bricks of matter are for the physicist.
0:43:59 > 0:44:04Like them, we must rely on echoes and shadows like these.
0:44:04 > 0:44:08John Cherub visited CERN again for the purpose of this film.
0:44:08 > 0:44:12He talks with John Bell, a CERN theoretician, about how to make a film about CERN.
0:44:12 > 0:44:15Well, it seems that one of the most difficult things
0:44:15 > 0:44:19we have to talk about is how actually to put across
0:44:19 > 0:44:22some of the basic ideas in particle physics
0:44:22 > 0:44:27that will be necessary to anyone who wants to understand what goes on here at CERN.
0:44:27 > 0:44:29What sort of people are you aiming at?
0:44:29 > 0:44:32- What sort of background do these people have?- Varied.
0:44:32 > 0:44:36I mean very varied indeed and for some,
0:44:36 > 0:44:41continuing interest in the sciences,
0:44:41 > 0:44:44sometimes a very well informed interest and sometimes not.
0:44:45 > 0:44:48And are you aiming to tell about particle physics
0:44:48 > 0:44:50or about particle physicists?
0:44:50 > 0:44:52Mainly about particle physics,
0:44:52 > 0:44:54but incidentally about particle physicists.
0:44:54 > 0:44:58So then you want a sort of formal lecture or somebody...
0:44:58 > 0:45:00On the contrary, no, no, no.
0:45:00 > 0:45:04Somebody starts by telling people matter is composed of small pieces
0:45:04 > 0:45:08and these small pieces are composed of still smaller pieces and so on.
0:45:08 > 0:45:11And the atom is something that you can describe to people
0:45:11 > 0:45:14because that's like the planetary system.
0:45:14 > 0:45:17There is a centre and there are a number of electrons
0:45:17 > 0:45:19going around this centre which is the nucleus.
0:45:19 > 0:45:22And it seems to me that you can tell people that.
0:45:22 > 0:45:25There's nothing strange about that except the scale,
0:45:25 > 0:45:26that it is very small.
0:45:32 > 0:45:37But as soon as you delve deeper into the atom, things get stranger.
0:45:41 > 0:45:44So the condition for a theory in which the infinities
0:45:44 > 0:45:47can be handled at all, a necessary condition
0:45:47 > 0:45:52is that the coupling constant has a dimensionality which is positive or zero.
0:45:52 > 0:45:55The coupling constant appears in the Lagrange,
0:45:55 > 0:45:57multiplying some kind of operator.
0:46:01 > 0:46:06Hidden within the maze of mathematics were descriptions
0:46:06 > 0:46:10of an array of sub-atomic particles no-one had ever seen before.
0:46:22 > 0:46:24To detect these particles,
0:46:24 > 0:46:30scientists built increasingly bigger and better accelerators.
0:46:30 > 0:46:33These are getting 100 times the energies they've got now.
0:46:33 > 0:46:36But it will be exciting. There have been tremendous advances
0:46:36 > 0:46:39in theoretical physics, in particle physics, since I came.
0:46:48 > 0:46:52And what gradually emerged from these atom-smashing experiments
0:46:52 > 0:46:57was a detailed picture of the very early universe.
0:47:08 > 0:47:14By the 1980s, particle accelerators were so powerful that they allowed
0:47:14 > 0:47:20scientists to catch a glimpse of what our universe looked like just moments after the Big Bang.
0:47:31 > 0:47:36Although great strides had been made by the particle physicists,
0:47:36 > 0:47:41the irritating fact remained that even with the mysterious dark matter
0:47:41 > 0:47:45that nobody could find, the Big Bang just didn't work
0:47:45 > 0:47:51without the ripples in the Penzias and Wilson cosmic background radiation,
0:47:51 > 0:47:55the telltale patches of hot and cold that the U2 spy plane had failed to detect.
0:48:02 > 0:48:06In a last desperate attempt to find the all-important ripples,
0:48:06 > 0:48:09a satellite called COBE was going to be launched
0:48:09 > 0:48:13on board a space shuttle in 1988.
0:48:16 > 0:48:20But on 28th January 1986,
0:48:20 > 0:48:22the entire project was thrown into jeopardy.
0:48:46 > 0:48:51The Challenger disaster meant that NASA had to reassess its whole space
0:48:51 > 0:48:56shuttle strategy and, before long, COBE was dropped from the programme.
0:48:58 > 0:49:02The COBE team were forced to find a substitute launch vehicle,
0:49:02 > 0:49:07and at last managed to get the satellite off the ground in 1989.
0:49:07 > 0:49:10Three, two.
0:49:10 > 0:49:12We have main engine start and lift off.
0:49:14 > 0:49:18lift off of Delta 189 and the Cosmos
0:49:18 > 0:49:23Observation Background Explorer. And the vehicle has cleared the tower...
0:49:25 > 0:49:32And when its data eventually trickled back to Earth, there was finally cause for celebration.
0:49:36 > 0:49:40This is the eve of the anniversary of COBE's launch,
0:49:40 > 0:49:43the third anniversary, and we're taking time out
0:49:43 > 0:49:47from the hard work to celebrate this great event.
0:49:47 > 0:49:49COBE is still gathering data.
0:49:52 > 0:49:56You see the unit infrared universe here with some stars
0:49:56 > 0:50:01in our galaxy showing up 300,000 years after the Big Bang.
0:50:03 > 0:50:07When we watched the COBE we thought it would only go maybe a year.
0:50:07 > 0:50:11That was what the original plan was, but we all hoped that it would go longer.
0:50:11 > 0:50:14So we're now actually in the third year and hoping
0:50:14 > 0:50:17to run successfully to run to the end of the fourth year.
0:50:17 > 0:50:21Their first results had been faint and difficult to interpret,
0:50:21 > 0:50:23but with an analytical team that's grown to 100,
0:50:23 > 0:50:25they now seem far more confident.
0:50:30 > 0:50:33There's the middle of our galaxy, and there's something else here.
0:50:33 > 0:50:36This part of the sky is much brighter than this part.
0:50:36 > 0:50:40Much brighter means one part in a thousand to us and it's not really much.
0:50:40 > 0:50:44But this is due to the motion of the Earth relative to the rest of the universe.
0:50:44 > 0:50:49Now, our data processing has actually proceeded to where we can subtract this part out.
0:50:49 > 0:50:51We can subtract out the emissions from our own galaxy
0:50:51 > 0:50:55across the middle and we can deduce the part that is really cosmic.
0:50:57 > 0:51:01The remaining tiny fluctuations compete with noise from the detector itself.
0:51:01 > 0:51:04It takes time to extract a signal from the noise.
0:51:11 > 0:51:14We started out at COBE knowing that nobody knew
0:51:14 > 0:51:16how these giant structures and clumpiness could occur.
0:51:16 > 0:51:21There's still no complete theory of how this clumpiness emerged
0:51:21 > 0:51:25and what it means, but at least they do have data for theorists to work on.
0:51:25 > 0:51:28This is a map of the universe as it was 300,000 years after
0:51:28 > 0:51:31the primeval explosion with a few additions here.
0:51:31 > 0:51:35This portion here in the middle is from our own galaxy.
0:51:35 > 0:51:39Now, what we see here are hot spots, the red ones are hot and the blue ones are cold,
0:51:39 > 0:51:44and those things are about a part in a hundred thousand brighter or colder than the average here.
0:51:44 > 0:51:48So these spots are going to grow up to be gigantic structures,
0:51:48 > 0:51:52300 million light years across in our present age.
0:51:52 > 0:51:54We have seen them before they've blown up,
0:51:54 > 0:51:57before they've expanded with the universe.
0:52:02 > 0:52:04It was the long-awaited result.
0:52:04 > 0:52:09At last the variations in the background radiation had been found,
0:52:09 > 0:52:12a quarter of a century since Penzias and Wilson
0:52:12 > 0:52:16had first heard the echo from the Big Bang.
0:52:16 > 0:52:23But, despite COBE, Fred Hoyle did not abandon his Steady State model.
0:52:23 > 0:52:29Hoyle remained violently opposed to the theory that he had inadvertently named.
0:52:29 > 0:52:31He went to his grave in 2001
0:52:31 > 0:52:36still believing that his theory was correct and that Big Bang was wrong.
0:52:43 > 0:52:46But the evidence was now stacked up against him.
0:52:46 > 0:52:51The fact that Hubble had observed galaxies hurtling away from each other,
0:52:51 > 0:52:54which meant our universe was expanding.
0:52:59 > 0:53:02That Penzias and Wilson had detected radiation
0:53:02 > 0:53:06left over from a primordial fireball.
0:53:06 > 0:53:09Main engines start, and lift off!
0:53:09 > 0:53:14And that COBE had detected ripples within this cosmic radiation.
0:53:18 > 0:53:25All of this has provided overwhelming evidence for a universe created by a Big Bang.
0:53:39 > 0:53:42Although, one problem persists.
0:53:42 > 0:53:47The wonderful dark matter, that is so handy when it comes to explaining
0:53:47 > 0:53:50how galaxies work, has still not been found.
0:53:55 > 0:54:00Not in the depths of a salt mine, nor in any of the existing particle accelerators.
0:54:08 > 0:54:11But this may be about to change.
0:54:13 > 0:54:16Very soon, the Large Hadron Collider
0:54:16 > 0:54:19at CERN in Geneva will be switched on.
0:54:19 > 0:54:23It's a particle accelerator capable of creating the conditions
0:54:23 > 0:54:28less than a billionth of a second after the Big Bang itself.
0:54:28 > 0:54:32For the first time in 13.7 billion years,
0:54:32 > 0:54:37scientists will be able to see what Hoyle claimed they never could.
0:54:37 > 0:54:41They will effectively be able to witness creation.
0:54:42 > 0:54:48This is like a huge new microscope that will bring us
0:54:48 > 0:54:51visibility to a different world.
0:54:51 > 0:54:55The universe, like everybody else,
0:54:55 > 0:54:58is made of pieces which need to be understood
0:54:58 > 0:55:01in order to understand how the universe works.
0:55:01 > 0:55:05Some of the technologies we are using did not exist
0:55:05 > 0:55:08when we started actually designing these detectors.
0:55:16 > 0:55:20So, just how do you go about building a Big Bang machine?
0:55:23 > 0:55:25First, burrow down 100 metres,
0:55:25 > 0:55:32drill through the rock until you have a 27-kilometre, circular tunnel.
0:55:34 > 0:55:40Around the tunnel cast vast chambers, each the size of a cathedral.
0:55:40 > 0:55:42Inside these,
0:55:42 > 0:55:46engineer the most complex cameras ever made to detect particles.
0:55:49 > 0:55:51Then, after nearly two decades,
0:55:51 > 0:55:55you can, at last, contemplate the experiment.
0:56:06 > 0:56:12The LHC will generate seven times the energy of any previous accelerator.
0:56:19 > 0:56:25By doing so, it will take us closer to the Big Bang than we have ever been before.
0:56:32 > 0:56:35You can feel, by walking in the corridors of CERN
0:56:35 > 0:56:38and of other laboratories in the world,
0:56:38 > 0:56:41that the enthusiasm is increasing again
0:56:41 > 0:56:44in anticipation of what may happen.
0:56:48 > 0:56:53The scale of the forces at work in this process is unprecedented,
0:56:53 > 0:56:57the experiment - a step into the unknown.
0:57:01 > 0:57:04Science is what we do when we don't know what we're doing.
0:57:08 > 0:57:10That's a very good scene for science.
0:57:10 > 0:57:13Revolutions sometimes come from the fact that you hit a wall
0:57:13 > 0:57:16and you realise that you haven't understood anything.
0:57:19 > 0:57:24Some believe it's the only way we can grasp the reality of our universe.
0:57:26 > 0:57:28We are actually at a point where
0:57:28 > 0:57:32only experiments can tell us what the way forward is.
0:57:37 > 0:57:41From a leap of faith, prompted by what one man recorded
0:57:41 > 0:57:46from scanning the heavens in 1929,
0:57:46 > 0:57:50to teetering on the very brink of scientific fact in 2008,
0:57:50 > 0:57:55the Big Bang's journey through eight decades of philosophical debate
0:57:55 > 0:58:01and scientific endeavour might finally be approaching an historic denouement.
0:58:04 > 0:58:09On the other hand, if the final pieces of the cosmological jigsaw
0:58:09 > 0:58:12don't fall into place at the LHC,
0:58:12 > 0:58:15then our journey has only just begun.
0:58:54 > 0:58:57Subtitles by Red Bee Media Ltd
0:58:57 > 0:58:59E-mail subtitling@bbc.co.uk