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00:00November 26th, 2007 promises to be an extraordinary day.
00:21The most advanced scientific instrument ever built, the Large Hadron Collider, will be
00:26switched on.
00:31This moment could conceivably trigger a catastrophic event, a black hole able to destroy entire
00:42cities and earth itself.
00:48The scientists behind this experiment have something quite different in mind.
00:55We have the outrageous ambition to understand the world, how it works.
01:00That's our objective.
01:06Their method, nothing less than recreating the moment that exploded everything into existence.
01:19The Big Bang.
01:23You can feel by walking in the laboratories in the world that the enthusiasm is increasing
01:30in anticipation of what may happen.
01:35Whichever scenario awaits us, the countdown to this fateful day has begun.
01:52Particle physics is a strange job.
02:02You know, I go to work every morning and my job is to recreate the conditions that were
02:10present less than a billionth of a second after the Big Bang.
02:15Dr Brian Cox is among the 2,000 scientists who inhabit a labyrinth of tunnels deep beneath
02:22the suburbs of Geneva.
02:30Here lies CERN, the European Organisation for Nuclear Research, where they're putting
02:35the finishing touches to one of science's greatest endeavours.
02:42I think this is the most exciting place in all of science at the moment.
02:47This is the LHC.
02:49This is the machine that's going to recreate the conditions present just after the Big
02:53Bang.
02:54And I can think of no better place to be actually.
02:57This is exciting.
02:59Just look at it.
03:00It's blue.
03:01It's even an exciting colour.
03:12In just a few months' time, the LHC, or Large Hadron Collider, will begin this remarkable
03:28experiment.
03:34The hope is that in recreating the moments following the Big Bang, we can see how the
03:39indivisible units that make up our universe were made.
03:49And that could lead to a complete understanding of everything.
03:57Well, the very big questions that humanity has posed always are where we come from, what
04:07we're made of, what is the future of the universe.
04:11But the universe, like everybody else, is made of little pieces which need to be understood
04:16in order to understand how the universe works.
04:21I think we're all looking forward to finding out what's actually out there in nature.
04:24We all have our ideas, we all have our theories and we play with them, but we want to know
04:28what's really going on, what's really there.
04:36I think we are on the verge of a revolution in our understanding of the universe and now,
04:42I'm sure people have said that before, but the LHC is certainly by far the biggest jump
04:47into the unknown.
04:50Should the experiment succeed, it will complete a journey begun nearly 14 billion years ago.
04:57A journey that will take us back to the very beginning of time.
05:12The universe came out of nothing.
05:13It was nowhere because before it there was no time, there was also no space.
05:19There was truly, truly, truly nothing.
05:22That is to say, not even a place where it happened, not even a time at which it happened.
05:28Somehow, out of this nothing, came everything.
05:45Dust and gas gathered to form the stars, all 70,000, million, million, million of them,
05:54and counting.
05:57They clustered into 100 billion galaxies, spread over a distance of 700 billion trillion
06:04kilometres, at the very least.
06:12On the edge of one of these galaxies, nine billion years after the Big Bang, a minor
06:17planet was formed.
06:20It became known as Earth.
06:25And the reason we know all of this is because of a discovery made here just 300 years ago.
06:39Any time you look at the universe around you, you're always looking at the past.
06:43And the further out we look, the deeper we stare into the past.
06:51That discovery was the speed of light.
06:54And it's this that allows us to see back in time.
07:00Light travels at about 300,000 kilometres a second.
07:04That sounds very fast, but it still means it takes light eight minutes to get here from
07:08the sun.
07:09The further out you look, the further back in time you look.
07:12It takes light about half an hour to get here from Jupiter.
07:15We see Jupiter as it was about 30 minutes ago.
07:23The deeper into space we look, the longer the light takes to get here, and so the further
07:28back in time we see.
07:30The nearest stars are about four light years away.
07:34It takes light four years to get to us.
07:41That means when we look out into space, it's a time machine.
07:44We're seeing the past of our universe.
07:46You know, when we look out at distant galaxies, we're seeing what the universe was once like.
08:03If we could see far enough, we should, in theory, be able to follow the light back,
08:23little by little, to the beginning of the universe.
08:35Astronomers have gone to ever-greater lengths to try and do just this.
08:38There it is.
08:41OK.
08:42Ah, you did it.
08:50The quiz is, what's the nearest bright star that we can see from here?
08:56And the answer is...
08:57So, this is Sirius.
08:59This is the brightest star in the northern hemisphere.
09:01Or the brightest star in the sky.
09:02In the whole sky, actually.
09:03Or the brightest star in the sky.
09:04Eight.
09:05Eight light...
09:068.6 light years.
09:07That's...
09:08That's what it is.
09:13By observing the stars closest to us, we can understand the evolution of our universe.
09:21This is a proto-star, proto-planetary system in the process of formation.
09:27The beauty of this is that it's only 150 light years away, which means, with the biggest
09:31telescopes now on the ground, we can see the processes that formed where we came from.
09:36So the light left this star at the time of the US Civil War, give or take.
09:48Once we're outside our cluster of galaxies, we reach a time that predates our species.
09:55So that's the heart of the Virgo cluster.
09:57The light that we're now seeing left the galaxies at about the time of the extinction of the
10:01dinosaurs some 60 or 70 million years ago.
10:11Some events can take us back further still.
10:20This is M1, the Crab Nebula.
10:22This is the result of the supernova that blew up.
10:25When the supernova explosion was going on, it can be seen during daylight for about a
10:32million months.
10:33That's how bright it was.
10:34Yeah, they typically brighten 10 billion times.
10:36They're really spectacular.
10:44These dying stars illuminate the journey deeper into space and time.
10:49The advantage of having them be so brilliant is that they are therefore visible all the
10:54way through the extent of the visible universe.
10:58They really allow us to learn about the shade of the universe.
11:09Supernovae have been observed as far back in time and space as 11 billion light years.
11:16Yet there is more beyond here.
11:19Understanding it requires another leap of technology.
11:41When I first met my wife, she commented that whenever we left the house or left a restaurant,
11:47I would always look up at the sky to see if I could see the stars.
12:00I think that looking at a clear sky at night is still one of the great joys for any observational
12:06astronomer, even those of us who now work in the space business.
12:14Few things can take us further into the past than the Hubble Space Telescope.
12:21Orbiting nearly 600 kilometres above us, it frees it from the distorting effects of the
12:26Earth's atmosphere.
12:31We can see things that are approximately 10 billion times fainter than you can see with
12:37the unaided eye.
12:39You could easily see the light from a firefly at the distance of the moon.
12:48Hubble's ability to see into deep space has produced one of the most revealing glimpses
12:52of the early universe we have.
12:56Yet it started as a shot in the dark.
13:00We formulated a plan by which we would point the telescope at an otherwise ordinary and
13:06blank spot in the sky and expose long enough that we would just be able to reveal whatever
13:15was there.
13:18I've got on the screen here a picture of the sky.
13:21We were interested in a part of the sky called Fornax.
13:26This tiny piece of sky, the size of a pinhead held at arm's length.
13:34As the telescope started to send back images, Beckwith couldn't be sure they would reveal
13:39anything new.
13:41I've zoomed in on the first image right here, and you see these are galaxies, OK?
13:46These are clearly galaxies, but the rest of it is just... it's noise.
13:54Only by amassing a total of 400 individual images could this dark corner of the universe
14:00be illuminated.
14:03OK, so now what I'm going to do is I'll build up the image.
14:08You'll begin to see faint things here.
14:10You see these things?
14:13And indeed, you can see them coming out.
14:15You can see all of this, see how beautiful that is?
14:18So as you add more and more images together, pretty soon now these things look quite bright.
14:27In the end, we expose the telescope to the sky for a million seconds.
14:33It's the longest exposure that's ever been taken with an optical telescope.
14:41All of a sudden, all these faint things just emerge clean from the noise, and that's the
14:46process.
14:47That's how it works.
14:48If I had another million seconds, it would look even better.
14:56The result of this painstaking process is an image that can take us back more than 13
15:02billion years.
15:06So we're flying now into the universe, and we're going back in time, and as we zoom in
15:16farther and farther, you will come up to the point where here we have what ultimately becomes
15:22the Hubble Ultra Deep Field.
15:37These little circles here show you places where we think we've detected the most distant
15:42galaxies that people have ever seen in the universe.
15:47And we'll zoom in on a couple of these, just so that you can see them.
15:53Traveling this far back, we see the universe in its infancy.
15:58This is a place where galaxies are barely formed, and yet to take on the distinctive
16:03shapes of later ones.
16:06If you look out to the most distant galaxies, you don't see any galaxies that look like
16:12the nearby ones.
16:13You see no spiral galaxies, you see no regular elliptical galaxies, you see nothing that
16:18looks familiar.
16:23We are looking back to a time when the universe was so young, it actually looks different.
16:29And this is a palpable demonstration of the whole idea of the Big Bang.
16:38Hubble Ultra Deep Field can take us to within 700 million years of this first moment.
16:45It is as far as today's technology can allow us to see into the past.
16:51We're already getting close to the point where going farther back will not reveal very much,
16:55because at some point, at some time, there weren't any stars, and so there's really nothing
16:59to see.
17:00And we are very close to that time in this image.
17:04We are almost at what I would call the visual edge of the observable universe.
17:14Beyond here lies a time before there were enough stars to illuminate space, a place
17:20called the Cosmic Dark Ages.
17:32Buried deep within this darkness is the earliest picture we have of our universe.
17:43Hello!
17:47Hello!
17:51Is there anyone out there?
17:55Hello!
18:01This vision first came to light here more than 40 years ago.
18:05Ever since, it has been a landmark for astronomers.
18:10Last time I was here was about 25 years ago, and it was pretty exciting to come here.
18:15It's kind of exciting to come back.
18:18I've not been, you know, haven't been back since.
18:21And this is where it all started.
18:25What led to the discovery of this image was an earlier advance in ways of seeing into space.
18:35Since the 1930s, astronomers had realized that in addition to what the human eye could see,
18:41the universe could be observed through invisible light.
18:47Light from the ultraviolet, infrared, and even radio wavelengths could all reveal hitherto
18:54unknown details about space, so long as you had the know-how.
18:59So what you've got to do is swing this thing all the way around,
19:03so that's pointing up at the sky, and then map the sky.
19:13So the signal comes in, hits the horn, bounces off the horn,
19:17and is brought to the receivers over there.
19:20Into this room, which is awful looking.
19:24What a mess.
19:27Let's see what's here.
19:29Here we go.
19:31There's the surface of the horn. Look straight down there.
19:35So the signal comes up, comes through here,
19:38you put your detector here, and pick up the signal.
19:43It was not until 1964, when two astronomers took up residence in the horn antenna,
19:48that this new way of seeing came into its own.
19:52Here we go. Here's the phone numbers.
19:54There's Bob Wilson.
19:57Up here we have Arno Penzias.
20:06Arno Penzias and Bob Wilson had simply set out to observe our galaxy,
20:11seeing the invisible light waves with their specialised telescope.
20:16But before they could even get started, they ran into problems.
20:22The telescope kept picking up an interference,
20:25a constant background signal that prevented them from taking any useful readings.
20:32I have to imagine they spent most of their time in here,
20:36scratching their heads, trying to figure out why they were picking up the signal.
20:41You know, they thought everything was working perfectly,
20:44there shouldn't be any background signal, yet it was there.
20:55They began looking for a source for the signal,
20:58but with no obvious cause, everything around them was suspected.
21:04Old parts were replaced.
21:06Even a pair of pigeons roosting in the horn were evicted,
21:09just in case their droppings were to blame.
21:12Still, the signal persisted.
21:16What would people think if we were to publish this result?
21:19When we started out, it was a nuisance.
21:21Then it got to be a puzzle, and finally an embarrassment.
21:27After a whole year of failing to locate a source for the signal,
21:31only one remarkable possibility remained.
21:35We eliminated just about everything,
21:37and then the only possibility was that it was coming from
21:41someplace outside our galaxy, and that seemed like such a far-out idea.
21:44We just didn't know what to do with that result.
21:52Eventually, they shared their findings with other astronomers,
21:56and were made to realise that they had stumbled across something quite incredible.
22:06The signal was the last remnant of light from the Big Bang.
22:11These light waves had survived since those first moments,
22:15but the expansion of the universe had stretched them out
22:19until they had become invisible.
22:24Nearly 14 billion years later,
22:27they had found their way into Penzias and Wilson's telescope.
22:34They won the Nobel Prize for that.
22:36Yeah, and well-deserved.
22:38I mean, it was a great discovery that opened up a whole field.
22:50The ancient light that Penzias and Wilson discovered
22:53continues to yield clues to the nature of the early universe.
22:59Professor David Spurgill has examined it
23:01with the very latest generation of space telescopes,
23:04the WMAP satellite.
23:08So what we're seeing is the oldest light,
23:11and it gives us, kind of, since we're looking back in time,
23:14this fossil picture of what the universe was once like.
23:18And we're really seeing the universe's baby picture,
23:21what it was like in its infancy.
23:28By recording the varying intensities of this light,
23:31WMAP reveals how the universe would unfold.
23:38Within these differently coloured ripples
23:41can be seen the areas that would later become star-forming regions,
23:45and eventually galaxies.
23:48We can really use the observations to tell us
23:51a tremendous amount about the properties of the universe,
23:54its composition, its age, its geometry,
23:57and what happened in its first moments.
24:04In all, it's a fascinating discovery,
24:07In all, WMAP can take us back
24:09to within just 400,000 years of the Big Bang.
24:21But one fact remains.
24:24While we can now paint a picture of the universe as an infant,
24:28we still can't watch its birth.
24:31Before this, the universe was so dense
24:33that light simply couldn't escape.
24:37It is a part of the story that will always be invisible.
24:43To see further back,
24:45we have to return to the other end of time and space.
25:02It's a journey back through the first stars.
25:06Back through the spiral galaxies.
25:10Back through our solar system.
25:13In all, through nearly 14 billion years of cosmological evolution
25:19to the planet Earth.
25:25More precisely, to a network of tunnels
25:28that straddle the French-Swiss border.
25:31The machine under construction here,
25:33the Large Hadron Collider, or LHC,
25:36promises to show us the moment that nature has hidden from our view.
25:42The moment just after the Big Bang.
25:45What it does is it recreates the conditions that were present
25:48less than a billionth of a second after the Big Bang,
25:51but in a controlled environment inside giant detectors.
25:57It's a really...
25:59It's a really...
26:01It's a really...
26:03It's a really...
26:05It's a really...
26:07It's a really...
26:09It's a really...
26:11It's a really...
26:14It's a really...
26:16You can repeat that over and over again
26:18and study it in exquisite detail.
26:20So, in some ways, it's almost better
26:23than going back to the start of the universe and watching,
26:26because you only get one chance to watch it.
26:31So just how do you go about building a Big Bang machine?
26:40First, burrow down 100 metres.
26:43Drill through the rock until you have a 27-kilometer circular tunnel.
26:52Fill this with 2,000 superconducting magnets, and you have a particle accelerator.
27:05Around the tunnel, cast vast chambers, each the size of a cathedral.
27:10Inside these, engineer the most complex cameras ever made
27:14to detect the particles.
27:19So, after nearly two decades' hard work,
27:21and having sunk around two-thirds of the $6 billion budget
27:24into the building alone,
27:26you can, at last, contemplate the experiment.
27:30So, we're going to enter the underground experiment cavern.
27:33We are about 100 metres underground.
27:35Some of the technologies we're using did not exist
27:38about 16 years ago when we started actually designing these detectors
27:42and thinking about doing experiments at the LHC.
27:49Once the machine is running,
27:51subatomic particles called protons will be accelerated
27:54until they are close to the speed of light.
27:59So, there's a beam of protons which comes at about this level,
28:02one way, and there's a counter-rotating beam of protons
28:05coming the other way, and they collide head-on.
28:12Every second, there will be 800 million collisions.
28:18Just a tiny fraction will be of interest.
28:22As the protons fragment,
28:24a magnetic field generated by the detector
28:27separates out the different types of matter.
28:30Among these pieces may be found the indivisible units
28:33that make up our entire universe.
28:39Some will exist for just one-thousandth of a billionth
28:42of a billionth of a second.
28:47And in these fleeting images,
28:49we can glimpse the first moments following the Big Bang.
28:53So, what we're trying to do is to find out
28:55what nature was like at that instant
28:57The scale of the forces at work in this process are unprecedented.
29:01The experiment, a step into the unknown.
29:06Some believe it is the only way
29:08we can grasp the reality of our universe.
29:11We actually are at a point
29:13where only experiments can tell us what the way forward is.
29:17Yet there remains a risk
29:19that the LHC may be opening the door
29:21to more than we ever imagined.
29:26One possibility is discovering the existence
29:29of other, unseen worlds alongside us.
29:35We certainly seem to think we see
29:37a lot of things that we don't see.
29:39We don't see things that we don't see.
29:41We don't see things that we don't see.
29:43We certainly seem to think we see
29:45three dimensions of space,
29:47up, down, left, right, forward, backwards.
29:49But there could be other dimensions
29:51that we just don't observe.
29:53It might not even be that light travels in those dimensions,
29:56which might explain why we don't see them.
29:58Or they could be very tiny,
30:00which could explain why we don't see them.
30:02But these other dimensions are dimensions
30:04outside the ones that we experience directly.
30:08Should these extra dimensions be real,
30:10the LHC could unveil them.
30:13The proof of their existence would be stranger yet.
30:19Matter simply vanishing.
30:23In effect, a black hole.
30:27Could you make black holes?
30:29And it's possible that if we get to high enough energies
30:32that we will be able to see evidence
30:34that there were higher-dimensional black holes.
30:38These black holes could conceivably grow.
30:43Dragging gravity and everything with it
30:46into an extra, unseen dimension.
30:51The chances of this happening
30:53are, according to the scientists, extremely small.
30:56These black holes wouldn't be dangerous.
30:58They would decay right away.
31:01These black holes actually evaporate
31:03as soon as they're produced.
31:05So it's almost impossible
31:07that these black holes can devour
31:09the experiment or Geneva or the Earth.
31:13MUSIC
31:18Instead of destroying the Earth,
31:20these scientists hope to answer the ultimate question.
31:23By going back to the beginning of the universe,
31:26they hope to come up with nothing less
31:28than an explanation for everything.
31:32The further back in time you look,
31:34so you go back to hotter and hotter conditions,
31:37back to Oz or the Big Bang,
31:39the simpler things appear to be.
31:43MUSIC
31:47To understand the universe today,
31:49it's just too complicated.
31:51You can't look at a person or a planet or a star
31:54and work out what the fundamental building blocks are.
31:57It's too difficult.
32:02But if you go back to those early times,
32:04all that's there is a very simple structure,
32:07just a few particles and a few forces,
32:10and then you can begin to try and understand
32:13how that simplicity evolved
32:15into the complexity that we see today.
32:26This dream has been the pursuit of scientists for years.
32:34Few have been more successful in the search
32:37than particle hunter Leon Lederman.
32:40WHIRRING
32:44And few have been more rewarded.
32:46This is a very important room.
32:48I have all my medals here.
32:50That's the Enrico Fermi Award.
32:52This is that one.
32:54There's the President of the United States.
32:56That's Lyndon Johnson.
32:58And that's another president.
33:00I think his name was Clinton.
33:02National Medal of Science.
33:05This is Alfred Nobel.
33:10Oops!
33:11I guess I damaged it.
33:13It's the Nobel Medal, which is rather nice.
33:17It's mostly gold, but there are all kinds of other medals here.
33:21I have an important medal,
33:23which is perfect attendance in sixth grade.
33:32Within the course of his own lifetime,
33:34Lederman has transformed our understanding of the universe.
33:40It's not true that I watched the Big Bang.
33:43People are lying.
33:45But in the late 40s, early 50s,
33:48we didn't know anything about these particles.
33:51We knew about atoms,
33:53but we had no idea of the complexity of matter.
33:58Lederman's discoveries have taken us deeper
34:01into the nature of matter,
34:03peeling away the layers of the atom
34:05to reach ever smaller particles.
34:07The moment of discovery is really a series of moments.
34:11The experiment is working.
34:13We think it's OK.
34:15And then finally, hey, look at that!
34:17There's an event.
34:21Eventually, get enough data to say
34:24we're beginning to see a class of particles
34:28that must have a very important role
34:31in the evolution of the universe.
34:37Part of the secret to Lederman's success is timing.
34:49He came to physics just as scientists were testing
34:52the radical theories that had arisen
34:54in the first half of the 20th century.
35:00The most astonishing was encapsulated
35:02in just five characters.
35:04It was special relativity by Albert Einstein.
35:15This equation stated that E, meaning energy,
35:18and M, or mass,
35:21are inextricably linked.
35:28That basically says that energy and mass
35:32are two sides of the same coin.
35:34They're basically the same thing
35:36and they're interchangeable.
35:38In this idea, I think Einstein was truly the first.
35:41Mass is just a form of energy.
35:43That was a very deep insight of Einstein.
35:46There's absolutely no question
35:48and there was no precedent for that idea.
35:54After Einstein,
35:56matter could be seen
35:58as just a highly concentrated form of energy.
36:02Energy that could be unleashed.
36:09But the really extraordinary thing about the equation
36:12was that it worked both ways.
36:17Energy could also make matter.
36:22This insight would open the door
36:24to a mysterious world
36:26that had been beyond the reach of science.
36:28The world that contained
36:30the secrets of the universe.
36:32The world of the subatomic.
36:39By subjecting atoms to high energies,
36:42scientists could reveal the types of matter
36:45that until then had been hidden from view.
36:52The greater the energy,
36:54the deeper they could peer into this world.
36:56Until they reached the final level of all,
36:59the indivisible building blocks
37:01that make up everything we see in the universe.
37:04The fundamental particles.
37:09In effect, they were winding the clock back
37:12toward the moment when energy first became matter.
37:17The Big Bang.
37:23The up quark, the down quark,
37:25the electron, the electron neutrino,
37:27the W plus and the W minus.
37:30As they made their discoveries,
37:32scientists began to name these fundamental particles.
37:37The charm quark, the strange quark,
37:39the muon and the mu neutrino.
37:44With these building blocks,
37:46they came to a remarkable understanding of the world.
37:49The top quark, the bottom quark,
37:51the tau and the tau neutrino.
37:53Now they could explain
37:55what anything and everything is made of.
37:59The Z particle and the photon.
38:05This list of exotic names
38:07was simply called the standard model.
38:10That's the standard model.
38:12Oh, no, the gluon.
38:15Don't forget the gluon.
38:19It appeared to be the perfect theory.
38:23The standard model was a fabulous achievement.
38:26It describes the most basic elements of matter.
38:30Even though we can't see those particles in our daily lives,
38:33we do know how they interact and we know they're there
38:36and that they are fundamentally what matter is made up of.
38:39It's beautifully precise,
38:41arguably the most precise mathematical theory ever constructed.
38:45The standard model amounts
38:47to just 12 unfathomably small matter particles.
38:53Lederman was among the first to set eyes on two of them.
38:59To this day, he continues to work
39:01at the site of some of his greatest discoveries,
39:04Fermilab, near Chicago.
39:06Until the completion of the LHC at CERN,
39:09this collider, six kilometres in circumference,
39:12remains the world's most powerful.
39:21Here, they can take us closer to the Big Bang,
39:24the world's largest black hole,
39:26the world's largest black hole,
39:28the world's largest black hole,
39:30the world's largest black hole,
39:32the world's largest black hole,
39:34they can take us closer to the Big Bang than anywhere else.
39:45Hi.
39:46Hi.
40:03This looks very, very Hollywood.
40:05We never really could get the kind of appearance
40:09you had on Star Trek.
40:16Despite his past successes,
40:18Lederman's search for the fundamental nature of reality
40:22is not yet over.
40:26We have the outrageous ambition
40:28to understand the world, how it works.
40:30That's our objective.
40:32We're confident that what we're doing here
40:35is something that is going to be valuable
40:38for human existence on this planet.
40:43The reason the search goes on
40:45is because not all is perfect
40:47with our understanding of the universe.
40:50The Standard Model may explain much,
40:53but it's not complete.
40:55Something fundamental is yet to be found.
40:59There's something spooky about this Standard Model.
41:03It doesn't really work.
41:05So we know that there's something sick in our theory.
41:10The thing that is missing
41:12is the thing that gives the fundamental particles substance,
41:16that turns them into matter we can touch.
41:19It's called mass.
41:28There's a big hole in our knowledge appeared,
41:31and the hole is related to what mass is.
41:34Why does the stuff that makes up you and me...
41:37Well, why is it stuff? Why is it solid?
41:42Without mass,
41:44the fundamental particles would all travel at the speed of light.
41:49The universe that we see simply wouldn't have formed.
41:54Well, of course, it would be nothing like...
41:56I mean, there would just be radiation.
41:58The fact that matter can clump
42:00relies on the fact that there's mass.
42:03The masses that we see
42:05are essential to the nature of matter as we know it.
42:15In order to solve this puzzle,
42:17to connect the discoveries of the Standard Model
42:20with the world we see around us,
42:22scientists had to come up with a new theory.
42:25The best theory we have at the moment for the origin of mass,
42:29for what makes stuff stuff,
42:31is called the Higgs mechanism.
42:35The Higgs mechanism works by filling the universe with a thing.
42:40It's almost like treacle.
42:46And by the universe,
42:48I don't just mean that the universe is made up of particles,
42:52and by the universe,
42:54I don't just mean the void between the stars and the planets,
42:57I mean the room in front of you.
43:02Some particles move through the Higgs field
43:05and talk to the Higgs field and slow down,
43:08and they're the heavy particles,
43:10so all the particles that make up your body
43:13are heavy because they talk into the Higgs field.
43:16Some other particles, like particles of light, photons,
43:20don't talk to the Higgs at all
43:22and move through at the speed of light.
43:30The Higgs field is the missing piece in the Standard Model.
43:34It can explain how we can have a world of solid objects
43:38from particles that appear to have no mass.
43:41The Higgs brings simplicity and beauty to a nature
43:45which looks too complicated.
43:47It introduces a kind of symmetry and a kind of beauty to nature
43:52which gives us an understanding
43:54of one of the most puzzling features of the Standard Model.
44:01Lederman now believes that finding the Higgs
44:04is the key to his ultimate goal.
44:06A complete theory of how the universe works.
44:12If, in fact, we can get over the Higgs particle,
44:16it may be that we can go a long way
44:19towards the horizon of a total understanding.
44:26To prove the existence of the Higgs field,
44:29scientists have used the Higgs field as a model
44:33To prove the existence of the Higgs field,
44:36scientists have to find the particle linked with it.
44:43Yet in the 40 years since it was first thought of,
44:46no-one has.
44:48And none have tried harder than Lederman.
44:54Now his hopes of ever seeing this particle lie elsewhere...
44:58with the LHC.
45:02This is like a huge new microscope
45:06that will bring us visibility to a different world.
45:12It would be a tremendous discovery.
45:28The LHC will generate seven times the energy
45:31of any previous collider.
45:44By doing so, it will take us closer to the Big Bang
45:47than we have ever been before.
45:49Will we find the Higgs particle at the LHC?
45:52That, of course, is the question.
45:55And the answer is,
45:57science is what we do
45:59when we don't know what we're doing.
46:01And one reason to look for this thing
46:03is to see whether we find it or not.
46:05So I don't know whether we will find it or not.
46:13The LHC is the only particle
46:16that we will find it or not.
46:21This is the other possibility,
46:23that this elusive particle,
46:25one that scientists have been searching 40 years for,
46:28simply doesn't exist.
46:39It can be argued that the most interesting discovery
46:43will be that we cannot find the Higgs,
46:46proving practically that it isn't there.
46:55That would mean that we really haven't understood something.
46:59That's a very good scene for science.
47:01Revolutions sometimes come from the fact
47:03that you hit a wall and you realize
47:05that you truly haven't understood anything.
47:13If the Higgs doesn't turn up,
47:15then the LHC has got so much energy
47:18that it has to uncover the origin of mass one way or the other.
47:28Whatever it is that gives substance
47:30to both ourselves and the world around us,
47:33the LHC promises to give us the answer.
47:38And with that, we will be one step closer
47:41to understanding how our universe evolved
47:44out of the first moment of time.
47:51It may be there is no such thing as a theory of everything,
47:54but it may also be that there is such a thing
47:57and we're very close to it at the moment.
47:59It might be within our grasp and that's what I hope.
48:02I hope that my generation is the generation that finds that theory.
48:11.
48:25If you would like to take your own journey
48:27through space and time,
48:29then visit our broadband site.
48:31There you can find web exclusives
48:33and a video podcast of tonight's programme.
48:36Just log on to bbc.co.uk
48:39forward slash horizon.