0:00:16.457,0:00:19.736
When I was a boy, my dad used to[br]pick me up after school.

0:00:19.736,0:00:23.432
I was about 11 years old,[br]in Geneva, Switzerland,

0:00:23.432,0:00:25.768
and he'd drive me across town [br]

0:00:25.768,0:00:29.224
to the site of the Large Hadron Collider,[br]in Geneva,

0:00:29.224,0:00:32.120
which was called the European[br]Center for Nuclear Research, at the time.

0:00:32.120,0:00:35.559
It's where they discovered[br]the Higgs boson a few years ago.[br]

0:00:35.559,0:00:38.157
There was a remarkable man there,[br]Rafael Carreras,

0:00:38.157,0:00:41.555
who used to give weekly lectures[br]called in French

0:00:41.555,0:00:44.321
'Science Pour Tous' which means[br]'Science for Everybody'.

0:00:44.321,0:00:47.718
There were people from all walks of life[br]who attended these lectures.

0:00:47.718,0:00:52.951
There were school boys like me, [br]janitors at CERN, professors, housewives.

0:00:52.951,0:00:56.712
A whole mix of people were attending[br]that stuff who gave up their lunch hour.

0:00:56.712,0:00:58.362
They were also working people.

0:00:58.362,0:01:01.078
There were two things that struck me[br]about these lectures.

0:01:01.078,0:01:04.884
The first thing was that people were[br]doing this not for any personal benefit,

0:01:04.884,0:01:06.902
there was no credit, no remuneration,

0:01:06.902,0:01:09.470
but they were just doing it[br]because it interested them.

0:01:09.470,0:01:12.899
I thought this was rather wonderful[br]and sort of put a light bulb in my head

0:01:12.899,0:01:16.520
that maybe you could go through life doing[br]what interests you rather than

0:01:16.520,0:01:19.553
what doesn't interest you in order to,[br]then, do what interests you.

0:01:19.553,0:01:21.745
You could short-circuit things. [br](Laughter)

0:01:21.745,0:01:24.721
The other thing I liked is, Dr. Carreras[br]was always encouraging.

0:01:24.721,0:01:27.007
I'd often go[br]and ask him questions and so on.

0:01:27.007,0:01:29.413
He never looked down on me as a kid.[br]

0:01:29.413,0:01:31.469
There weren't any stupid questions.

0:01:31.469,0:01:33.447
You could go and ask him anything[br]

0:01:33.447,0:01:35.565
and there was always stuff to be learned

0:01:35.565,0:01:37.615
and I liked this environment so much,[br]

0:01:37.615,0:01:40.015
I think it set me on a path[br]to ending up here

0:01:40.015,0:01:42.415
where I am a professional scientist[br]talking to you.

0:01:42.415,0:01:44.729
Even before then, [br]my dad used to read me stories

0:01:44.729,0:01:47.043
from the 'Winnie the Pooh' books

0:01:47.043,0:01:49.357
and there's a picture here [br]of Winnie the Pooh and Piglet

0:01:49.357,0:01:51.254
searching for a Heffalump.

0:01:51.254,0:01:53.963
A Heffalump's a very rare [br]and unusual thing

0:01:53.963,0:01:56.570
that had almost, maybe never, been seen.

0:01:56.570,0:01:58.907
But they got circumstantial evidence here.[br]

0:01:58.907,0:02:01.037
They' ve seen footprints in the snow

0:02:01.037,0:02:02.493
and this has encouraging them,

0:02:02.493,0:02:04.409
maybe if we continue work [br]a little bit harder,

0:02:04.409,0:02:05.986
maybe we could find this thing.

0:02:05.986,0:02:09.859
So the basic difference betweeen me [br]and Winnie the Pooh in this picture

0:02:09.859,0:02:12.648
is that he's looking down[br]and I look up for a living.

0:02:12.648,0:02:15.467
So, we scientists, in particular,

0:02:15.467,0:02:18.366
the subject of this talk is to look for[br]the first stars

0:02:18.366,0:02:22.126
and galaxies to form after the Big Bang.

0:02:22.126,0:02:24.901
They're rare and unusual objects.[br]We think they are very different

0:02:24.901,0:02:28.491
to the stars and galaxies[br]that we can see around us today.

0:02:28.491,0:02:30.427
But we think they are there.

0:02:30.427,0:02:33.043
We have circumstantial evidence[br]that makes us think

0:02:33.043,0:02:35.890
that they are there [br]so the quest is worth following.

0:02:35.890,0:02:40.260
So I've told you these two anecdotes[br]maybe a bit from my life

0:02:40.260,0:02:42.317
in order to give the idea [br]of a timeline also

0:02:42.317,0:02:44.526
that I sit here today looking in my past

0:02:44.526,0:02:46.895
as we all can towards when I was born,

0:02:46.895,0:02:49.845
and you can see significant events[br]that shaped your life.

0:02:49.845,0:02:53.609
What's remarkable is that we can do[br]the same thing for the Universe.

0:02:53.609,0:02:56.098
So the Universe originated in a Big Bang.

0:02:56.098,0:02:58.587
We don't know exactly what banged[br]or how it banged,

0:02:58.587,0:03:01.077
although, a couple of weeks ago,[br]we had some indications

0:03:01.077,0:03:02.939
if you followed the science news.

0:03:02.939,0:03:05.387
But we know when it banged[br]to amazing accuracy.

0:03:05.387,0:03:08.474
So, we know the Big Bang was[br]the creation of time and space.

0:03:08.474,0:03:11.561
Matter and light happened[br]14 billion years ago.

0:03:11.561,0:03:14.648
We know the exact number to 1% accuracy.

0:03:14.648,0:03:17.991
As I was bouncing back into my past[br]at the start of this talk,

0:03:17.991,0:03:20.848
we can do the same thing here in astronomy[br]

0:03:20.848,0:03:23.385
because light travels at finite speed.

0:03:23.385,0:03:25.489
So when we look up at the sky,[br]

0:03:25.489,0:03:27.723
we' re actually looking into the past.

0:03:27.723,0:03:30.268
And for most cases it's not so relevant.[br]

0:03:30.268,0:03:32.533
In the case of the moon [br]it's like 2 seconds.

0:03:32.533,0:03:35.690
When you see the moon, [br]you see it as it was 2 seconds ago

0:03:35.690,0:03:38.748
because that's how long it takes light[br]to reach us from the moon.

0:03:38.748,0:03:40.350
Naked eye stars that you can see

0:03:40.350,0:03:42.762
if you go out in the desert [br]away from the street

0:03:42.762,0:03:44.869
that may be a few thousand years.

0:03:44.869,0:03:47.526
You see them as if [br]they were a few thousand years ago.

0:03:47.526,0:03:50.355
But the most distant object [br]you can see with your naked eye

0:03:50.355,0:03:51.826
which is the Andromeda galaxy[br]

0:03:51.826,0:03:53.827
pictured here seen through a telescope,

0:03:53.827,0:03:56.759
is actually 2.4 million years ago.

0:03:56.759,0:03:59.983
So the light has taken 2.4 million years[br]to reach you.

0:03:59.983,0:04:03.257
Even without the aid of the telescope[br]you can see this object.

0:04:03.257,0:04:05.719
If you wanted to know[br]what it looked like today,

0:04:05.719,0:04:08.671
you'd have to wait another 2.4 million years.

0:04:09.771,0:04:13.575
So, the history of Astronomy [br]has really been the history of developing

0:04:13.575,0:04:17.846
telescopes and technology to be able [br]to push further out into space

0:04:17.846,0:04:21.147
and see even more distant [br]and remarkable things.

0:04:21.147,0:04:24.074
This is a picture of an object[br]known as a comet cluster,

0:04:24.074,0:04:26.711
many thousands of galaxies[br]like the Milky Way.

0:04:26.711,0:04:30.968
It's so far away that it's seen[br]250 million years ago, roughly speaking.

0:04:30.968,0:04:33.088
So 250 million years ago,

0:04:33.088,0:04:35.608
here there was a deep sea, [br]a deep inland sea.

0:04:35.608,0:04:39.310
We know this because we see[br]the Kaibab limestones of Red Rock.

0:04:39.310,0:04:44.681
We see these also, just downstream[br]from Glen Canyon down at Lee's Ferry.

0:04:44.721,0:04:48.662
These tell us the idea of what [br]was happening here was very different.

0:04:48.662,0:04:50.637
It wasn't a desert. It was an inland sea.[br]

0:04:50.637,0:04:52.612
But we don't see the thing itself.

0:04:52.612,0:04:54.588
We have circumstantial evidence,[br]the rocks.

0:04:54.588,0:04:56.601
But here we're seeing the thing itself[br]

0:04:56.601,0:04:59.154
as it was 250 million years ago.

0:04:59.154,0:05:01.327
So I've drawn sort of a timeline[br]

0:05:01.327,0:05:03.389
on the slide we have today [br]on the Big Bang.

0:05:03.389,0:05:06.223
The green arrow shows you[br]when the Earth formed.

0:05:06.223,0:05:09.159
So the Earth is a relatively recent[br]addition to the Universe.

0:05:09.159,0:05:12.555
It's only been there for a third[br]of the existence of the Universe.

0:05:12.555,0:05:15.723
For two thirds of the time [br]our solar system wasn't even there.

0:05:15.723,0:05:19.543
So how far back can we actually look[br]with our technology?

0:05:19.543,0:05:22.080
I've drawn here a little red square[br]on the slide[br]

0:05:22.080,0:05:24.177
which shows the field of view

0:05:24.177,0:05:26.736
of the best instrument that we built[br]to be able to do this --

0:05:26.736,0:05:30.383
you've certainly heard of it --[br]it's the Hubble Space Telescope.

0:05:30.383,0:05:33.451
The Hubble Space Telescope[br]has a very small field of view.

0:05:33.451,0:05:36.719
In other words, it takes[br]a very small picture of the sky at a time,

0:05:36.719,0:05:39.378
about 100th of the size of the moon.

0:05:39.378,0:05:43.128
If you want to picture that, it's like[br]coding a grain of sand at arm's length.

0:05:43.128,0:05:45.219
It's a very, very small part of the sky.

0:05:45.219,0:05:48.550
And scientists had the idea [br]to try and probe back in time

0:05:48.550,0:05:51.071
would be to take a picture of the sky

0:05:51.071,0:05:54.119
but to take two weeks [br]to observe one part of the sky.

0:05:54.119,0:05:58.020
This was a remarkable idea to look [br]at a nondescript, not a part of the sky

0:05:58.020,0:06:00.271
we'd thought[br]it wasn't anything interesting,[br]

0:06:00.271,0:06:02.102
but just to see what's out there.

0:06:02.102,0:06:03.964
What we found was remarkable.

0:06:03.964,0:06:07.145
Here's one of the most famous images[br]ever taken in astronomy.

0:06:07.145,0:06:08.958
It's a Hubble Ultra-Deep Field.

0:06:08.958,0:06:12.106
In an area the size of the grain of sand[br]held at arm's length,

0:06:12.106,0:06:14.094
you see ten thousand galaxies here.

0:06:14.094,0:06:15.812
They're not stars in our Milky Way.[br]

0:06:15.812,0:06:19.488
They're separate individual galaxies,[br]like our Milky Way.

0:06:19.488,0:06:23.054
In this image, about ten of them[br]are seen as they were

0:06:23.054,0:06:25.539
13.3 billion years ago,

0:06:25.539,0:06:28.184
which is to say[br]the light started on this journey

0:06:28.184,0:06:30.510
long before the solar system ever formed.

0:06:30.510,0:06:33.534
For most of that journey,[br]the Sun and the Earth didn't exist.

0:06:33.534,0:06:37.110
You know, the Sun and the Earth formed[br]and then life evolved and so on,

0:06:37.110,0:06:40.015
we built telescopes and boom,[br]we capture this light.[br]

0:06:40.015,0:06:42.210
It's utterly remarkable.

0:06:42.210,0:06:44.169
But those are not the first galaxies.[br]

0:06:44.169,0:06:46.918
Remember, we are looking[br]for the first stars and galaxies.

0:06:46.918,0:06:49.729
This is one of the major[br]scientific adventures, I think,

0:06:49.729,0:06:51.146
of the 21st century

0:06:51.146,0:06:54.923
which is going to play out[br]in the next ten years.

0:06:56.983,0:07:00.651
So we sit here and we look[br]at this Hubble Deep Field.

0:07:00.651,0:07:02.849
How do we select then the ten galaxies,[br]

0:07:02.849,0:07:05.667
the one in a thousand galaxies[br]that are the most distant.

0:07:05.667,0:07:08.456
It's so simple that I thought[br]I'd just tell you today.

0:07:08.456,0:07:10.730
What we do is not a technical description.[br]

0:07:10.730,0:07:14.094
We take a picture at visible wavelengths[br]of the Hubble-Deep Field

0:07:14.094,0:07:16.210
[br]and one at infrared wavelengths.

0:07:16.210,0:07:19.033
The galaxies which can be seen[br]in the infrared image,

0:07:19.033,0:07:22.023
but cannot be seen in the visible image,[br]those are the ones.

0:07:22.023,0:07:24.158
There's just a few of them,[br]there's just ten of them.

0:07:24.158,0:07:28.705
Those are the ones that are seen[br]13.3 billion years ago.

0:07:28.705,0:07:31.564
To summarize my story so far --

0:07:31.564,0:07:33.970
if I can get the next slide, there it is.

0:07:33.970,0:07:37.283
We sit here in the Milky Way[br]and we look further and further back

0:07:37.283,0:07:39.276
with more sophisticated telescopes.[br]

0:07:39.276,0:07:41.159
And we look further and further [br]back in time

0:07:41.159,0:07:43.702
13.3 billion years so far with the Hubble.[br]

0:07:43.702,0:07:46.165
But we have another piece of information

0:07:46.165,0:07:48.569
which is the cosmic background radiation.

0:07:48.569,0:07:51.811
The cosmic background radiation[br]which is seen at radio wavelengths

0:07:51.811,0:07:54.029
tells us what was happening[br]in the Universe[br]

0:07:54.029,0:07:56.707
only roughly half a million years [br]after the Big Bang.

0:07:56.707,0:07:58.869
We know there was a time from the staff,[br]

0:07:58.869,0:08:02.261
the outermost shell that's colored[br]green and yellow and blue there,

0:08:02.261,0:08:06.014
that there was a time when there were [br]no stars and galaxies in the Universe.

0:08:06.014,0:08:07.640
That's what that tells us.

0:08:07.640,0:08:09.990
But it tells us another important thing,[br]

0:08:09.990,0:08:12.720
which is that on its journey,[br]the slide on its way to us

0:08:12.720,0:08:15.031
was modified by stars and galaxies,

0:08:15.031,0:08:17.190
the first generation of stars and galaxies[br]

0:08:17.190,0:08:18.939
that we haven't yet detected.

0:08:18.939,0:08:21.509
That's a sort of Heffalump effect.[br]The footprints.[br]

0:08:21.509,0:08:24.032
We see the footprints[br]of the things we're looking for

0:08:24.032,0:08:26.556
but we haven't seen the thing itself yet.

0:08:26.556,0:08:29.527
So in order to find these things that[br]we're looking for,

0:08:29.527,0:08:31.348
we need to devise new tools.

0:08:31.348,0:08:34.390
The history of astronomy has been[br]the remarkable improvements

0:08:34.390,0:08:37.492
we've been added for 400 years[br]with the telescope.

0:08:37.492,0:08:41.184
Galileo's telescope [br]had a lens about this big[br]

0:08:41.184,0:08:44.686
and this is a next generation[br]of telescopes being built in Chile.

0:08:44.686,0:08:48.188
This is a European[br]Extremely Large Telescope --

0:08:48.188,0:08:51.146
running out of names for telescopes now. [br](Laughter)

0:08:51.146,0:08:54.624
But the mirror --

0:08:54.624,0:08:57.632
The mirror is about the size of this room

0:08:57.632,0:09:01.402
so it's a gigantic tool for looking back[br]into space ever further.

0:09:01.402,0:09:04.560
As you saw from before, [br]we need visible and infrared light

0:09:04.560,0:09:06.943
in order to study these objects.[br]

0:09:06.943,0:09:09.236
In the infrared, we' re building

0:09:09.236,0:09:12.360
what is the successor to the Hubble[br]Space Telescope

0:09:12.360,0:09:15.184
which is what's called[br]the James Webb Space Telescope.

0:09:15.184,0:09:17.668
This is just one sixth of it shown here.

0:09:17.668,0:09:19.765
So it's a gigantic instrument.

0:09:19.765,0:09:21.992
It's so big that it won't fit[br]into a rocket.

0:09:21.992,0:09:25.520
So they are going to have to fold it up[br]like insect wings or something,

0:09:25.520,0:09:29.405
put it in there, send it out into space,[br]take it out, unfold it

0:09:29.405,0:09:31.650
and then it's going to take what we hope

0:09:31.650,0:09:34.086
are the images [br]of the first stars and galaxies.

0:09:34.086,0:09:36.363
It's also going to explore planets

0:09:36.363,0:09:38.970
and other things[br]that are of great interest to us.

0:09:38.970,0:09:40.917
So, what do we expect to find?[br]

0:09:40.917,0:09:44.684
The way we do astronomy[br]is illustrated in this video here,

0:09:44.684,0:09:48.172
is astronomy and science [br]is a constant dialogue, really,

0:09:48.172,0:09:51.639
between theories or our conjectures [br]about the way things ought to be,

0:09:51.639,0:09:54.046
which is shown in the movie here,

0:09:54.046,0:09:56.985
and the way they actually are,[br]which is shown in the stills.

0:09:56.985,0:09:59.399
So in the movie here, [br]you can see two galaxies,[br]

0:09:59.399,0:10:02.293
like the Milky Way and Andromeda[br]that are on a collision.

0:10:02.293,0:10:04.949
This is a calculation done in a computer.

0:10:04.949,0:10:07.538
Once in a while, they freeze the movie[br]

0:10:07.538,0:10:09.527
and because it's a computer simulation

0:10:09.527,0:10:11.507
you can view it any way you like,

0:10:11.507,0:10:13.357
and then they try and compare it,

0:10:13.357,0:10:15.384
to actual images of galaxies nearby[br]

0:10:15.384,0:10:17.511
to see how good a job we have

0:10:17.511,0:10:20.130
at understanding interactions[br]between galaxies.

0:10:20.130,0:10:22.782
In the case of the most distant [br]stars and galaxies,

0:10:22.782,0:10:24.584
we've only done half of this.

0:10:24.584,0:10:27.957
We have our conjectures,[br]but we don't have the observations.

0:10:27.957,0:10:31.307
So what can we expect to see?[br]How is this going to play out?

0:10:31.307,0:10:33.100
Based on the history of astronomy,[br]

0:10:33.100,0:10:35.623
I think I can best tell it [br]with an anecdote.

0:10:35.623,0:10:39.166
Howard Carter, when they discovered[br]Tutankhamun's tomb,

0:10:39.166,0:10:41.378
they were in a sort of narrow corridor

0:10:41.378,0:10:44.160
and he was the first to see the tomb[br]in modern times,

0:10:44.160,0:10:47.733
and he had a candle [br]and in the flickering light he could see

0:10:47.733,0:10:51.584
this vast array of treasures of gold [br]and statues of animals and things.

0:10:51.584,0:10:53.973
The others behind him -- [br]he didn't say anything,[br]

0:10:53.973,0:10:56.712
and they were like: 'What do you see?'

0:10:56.712,0:10:58.879
And he said, 'Wonderful things',[br]'Wonderful things'.

0:10:58.879,0:11:01.046
And I think that's what we can expect

0:11:01.046,0:11:03.214
in our science in the future.

0:11:03.214,0:11:05.247
But as well as learning about the Universe

0:11:05.247,0:11:07.320
which is going to be tremendously exciting,[br]

0:11:07.320,0:11:10.881
I think, science teaches a lot about[br]our humanity, ourselves as human beings.

0:11:10.881,0:11:13.192
For those of you [br]who don't know the Pooh story,[br]

0:11:13.192,0:11:14.773
the punchline to this one is

0:11:14.773,0:11:17.094
they actually didn't find the tracks[br]of the Heffalump, unfortunately.

0:11:17.094,0:11:19.090
They were looking at[br]their own tracks in the snow.

0:11:19.090,0:11:22.276
But they learned something [br]about themselves in this adventure

0:11:22.276,0:11:24.553
and about what they were.[br]

0:11:24.553,0:11:26.970
We do this too, when we do science.

0:11:26.970,0:11:30.549
We learn our position in the Universe,[br]but we also learn about ourselves.

0:11:30.549,0:11:34.888
And the European Center for Nuclear Research[br]which has many --

0:11:34.888,0:11:37.123
several Nobel prizes [br]have been awarded there.

0:11:37.123,0:11:39.368
I didn't tell you this far,[br]it was built really

0:11:39.368,0:11:41.983
out of the ashes of Europe after WWII.[br]Europe had been at war.

0:11:41.983,0:11:44.035
I am an immigrant from Europe.

0:11:44.035,0:11:46.887
For most of the 20th century[br]for reasons that weren't clear,

0:11:46.887,0:11:50.551
but all these countries, [br]for religious, cultural, ethnic reasons

0:11:50.551,0:11:52.383
were at each other's throats.

0:11:52.383,0:11:54.713
And the idea is [br]maybe there is another way.[br]

0:11:54.713,0:11:56.193
What if we work together?

0:11:56.193,0:11:58.033
What if people from these countries[br]that had been at war

0:11:58.033,0:12:01.110
showed that by working together, [br]overcoming their prejudice,[br]

0:12:01.110,0:12:03.237
we can do good science?

0:12:03.237,0:12:04.916
And history of CERN has shown

0:12:04.916,0:12:07.045
that when you do this [br]you can achieve wonderful things.

0:12:07.045,0:12:08.824
Wonderful things!

0:12:08.824,0:12:10.346
Thank you.

0:12:10.346,0:12:12.513
(Applause)