The practice of science has shaped the modern era.
But how are discoveries made?
And how does science progress?
Three British scientists, world leaders in their fields,
have changed our understanding of our universe, our planet
and ourselves.
A physicist, whose mysterious radio signals from space
rewrote astronomy.
She actually recognised that there was something happening.
I suspect that perhaps only one in 100 people would have spotted it.
A chemist, whose radical theory about our planet
divides the scientific world.
He's one of the greatest thinkers of the current age,
and destined to go down in history.
And a biologist, who discovered the secret of life in a sea urchin.
Your fundamental discoveries have profoundly increased
our understanding of how the cell cycle is controlled.
Their stories tell us about the nature of scientific inquiry
in the modern world.
About how scientific breakthroughs are made.
And about the workings of the scientific brain.
Scientists should never claim that something is absolutely true.
You should never claim perfect or total or 100%,
because you never, ever get there.
If we assume we have arrived, we stop searching.
We stop developing.
In 1967, a PhD student called Jocelyn Bell
noticed something that shouldn't happen.
Strange, regular flashes of energy emanating from deep space.
She had discovered completely new types of stars
that came to be known as pulsars.
You were responsible for spotting
the very first pulsar personally, I think.
Jocelyn Bell's discovery fundamentally changed
science's understanding of the universe.
All of a sudden, people went from thinking about the universe
been relatively dull and boring,
to suddenly the universe is full
of these things flickering and flashing around.
It was really amazing and very exciting.
'The girl who started all the fuss about the pulsars, Jocelyn Bell,
'was a research student at Cambridge.'
Pulsars provided the first evidence
that Einstein's theory of gravity was right,
and resulted in the winning of a Nobel Prize.
But according to their finder,
their discovery tells us about the nature of science itself.
Science always doesn't go forwards.
It's a bit like doing a Rubik's Cube.
You sometimes have to make more of a mess with a Rubik's Cube
before you can get it to go right.
You build up this picture of what there is.
You believe it to be true and you work with a picture and refine it.
But sometimes you have to abandon the picture.
Sometimes you discover that the picture you thought you had,
that everybody thought we had, actually turns out to be wrong.
Way back in the Middle Ages,
they thought that planets went round the Sun in circles, perfect circles.
They had to be perfect, they were heavenly bodies.
And then they got better telescopes, better data and they recognised that
the planets weren't where they expected them to be.
They weren't in the right place.
But they were reluctant to relinquish the circles
so they invented epicycles, little circles on the rim of the big circle.
Like a roundabout of roundabouts.
And they could explain what they observed like that.
Then they got better telescopes and better data and found that they had
to add more epicycles and it got messier and messier and messier.
And then one of the key astronomers of the time, Johannes Kepler,
said maybe it's not circles, or circles plus epicycles,
or circles plus epicycles with epicycles on them,
maybe it's slightly squashed circles, ellipses.
And that cleared the air wonderfully,
and suddenly it was clear and simple again.
Constant questioning of assumptions
and probing of ideas has defined Professor Bell Burnell's career.
It is this philosophy that resulted in her becoming one
of the world's leading scientists.
An astrophysicist who believes her discipline
reveals the essence of who we are.
The kind of chemical elements that you find inside the human body,
hydrogen and oxygen in the water,
carbon in our tissue and calcium in our bones, iron in our bloodstream,
they've come from the Earth as that's where the plants got them from.
The Earth and the Sun, because they formed at much the same time,
got these chemical elements from previous exploding stars.
The material goes through a stellar cycle, explodes, gets incorporated
in the Sun and the Earth and into us.
When we die, those atoms will get returned to the Earth.
We are intimately and ultimately children of the stars.
We're made of star stuff.
So when we look at the night sky, we're seeing the kind of environment
that we came from, that the atoms of which we're made came from.
The roots of our being, if you like.
And that's why I find astronomy so important and so fascinating.
Jocelyn, how did you first become interested in the stars?
I've been interested as long as I can remember, Sue.
Dad had a subscription to the Linen Hall Library in Belfast
and brought home all sorts of books.
But the ones that really caught my attention
were two or three books about astronomy.
Fred Hoyle's Frontiers Of Astronomy and a book by Dennis Sciama.
Astronomical distances have the air of a conjuring trick.
The vastness of cosmic dimensions fills us with astonishment.
Yet like a conjuring trick,
it all looks very obvious when we see how it's done.
It was reading those books that made me realise
what an exciting and interesting subject astronomy was.
I find it fascinating that with a limited number
of snapshots or observations of the sky, we can deduce so much.
Not just the evolution of stars and galaxies, but actually
the evolution of the whole universe.
How it began, and how it'll end.
Nowhere else in science can you get this big picture.
It's unique to astronomy.
Today, a new moon is in the sky.
A 23-inch metal sphere placed in orbit by a Russian rocket.
The launch of the Sputnik satellite
was a real shock in Britain, and in the USA,
because both Britain and the US
believed they were in advance of the Soviets technically,
and then the Soviets go and launch a satellite, which we couldn't do.
You are hearing the actual signals
transmitted by the Earth-circling satellite. One of the great
scientific feats of the age.
So clearly there was some hard thought and head-scratching,
and as a consequence, there was suddenly a great emphasis on science.
Science was very well-regarded and any kids who could do science
were encouraged to go and do science.
And I was part of that movement.
My father would get us up to see Sputniks go by and he'd explain
to us the difference between a satellite and, say, a shooting star.
We named one of our cats after one of the satellites, in fact, Vostok.
So it was very much embedded in the family.
With the space race, science had acquired an air of glamour,
inspiring a new generation of scientists.
I went away to boarding school at age 13.
The physics teacher that I had, Mr Tillett, was a super teacher.
One of the things I remember him teaching us is that
once you got a grip on physics,
you only need to learn relatively few facts and then you can build on that.
You can develop a long, long way
from relatively few bits of information in the first place.
And that economy appealed to me.
I could well have had a physics teacher who took the view
that girls couldn't do physics, what's-the-point-of-trying?
I'm not sure where I'd have gone then, what I'd have done,
but Mr Tillett was quite the opposite.
But at university, Bell encountered a less enlightened attitude.
I went to Glasgow, and I was the only woman doing physics.
Every time I entered the lecture theatre, as was the tradition,
the guys whistled, stamped, cat-called, banged their desks.
And I had to learn not to blush
because if you blush, they do it more noisily.
It also had an isolating effect, there was a them and me.
I was rather on my own the whole time.
Since then, Professor Bell Burnell
has campaigned to encourage women into science.
Not for the benefit of women, but for the benefit of science.
One of the things women bring to a research project,
or indeed any project, is they come from a different place.
They've got a different background.
Science has been named,
developed, interpreted,
by white males for decades.
Women view the conventional wisdom from a slightly different angle,
and that sometimes means they can clearly point to flaws
in the logic, gaps in the argument.
They can give a different perspective of what science is.
For centuries, man has used his eyes to look at the stars.
But now he's found a new method of observing the universe.
The early '60s were very exciting times in astronomy,
particularly radio astronomy.
Radio astronomy was perhaps 10, 15 years old, coming into its prime,
discovering things right, left and centre. It was all going on.
It was fantastic.
Cambridge University, where Jocelyn Bell had started her PhD,
was leading the world in modern radio astronomy.
It's almost as if astronomers and indeed physicists were
in the position of Columbus at the time he discovered a new continent.
This is the way we feel at the present time.
There were a lot of big names around.
Stephen Hawking and Dennis Sciama and Fred Hoyle, and so on.
So there were a lot of very, very brilliant people there.
Jocelyn Bell had found her spiritual home.
It was here that glamorous Russian satellites,
Mr Tillett's inspirational teaching
and Glasgow University's trial by ordeal would start to bear fruit.
This is the Mullard Radio Astronomy Observatory.
A branch of the Cavendish Laboratory of Cambridge University.
And here we can see Dr Tony Hewish who will tell us more about it.
We were looking far beyond optical telescopes.
I mean, you felt very privileged, actually.
It was like opening a new window onto the universe and you
were the first people to have a look out through and see what was there.
And to realise that you were probing back in time.
Distance and time go together the further off you can see something,
the earlier in the history of the universe it actually happens to be.
Here we were looking back over the history of the universe, in a sense.
Discovering things that you could only discover that way.
One of the pioneers of radio astronomy is Martin Ryle.
With optical telescopes, one is limited to a range
of observation about here.
With radio telescopes, one can however detect galaxies
at greater distances and with a new large radio telescope at Cambridge,
we think we're being able to detect galaxies
right out to this region here.
The Cambridge Radio Astronomy Group had an interest in distant objects
because they were interested in general in how the universe
had evolved and therefore you want to try to see things
at early stages of the universe.
It was just so exciting, so stimulating.
The big question was - did the universe have a finite origin
in time, did it suddenly start, or was there no beginning?
Because one of the nice theories,
Fred Hoyle and others, the so-called steady state cosmology,
was that overall, the population of the universe with regard to stars
and galaxies was roughly constant
and that's why it was called the steady state universe.
Well, it turned out to be quite untrue.
Now, the observations we were making over the past two years,
seemed to show quite conclusively
that the steady state theory of the universe can't be correct.
The results imply that the universe is changing with time.
One was looking back at an earlier phase of the universe
and you can look back and say, well, was the universe the same
as the present day universe we see above us now?
And the answer to that was no.
The universe is evolving and that immediately rules out
the steady state and points in favour
of a sudden creation.
Each time you do research in science, you're tackling a question or two
and you find that you've got some more questions
uncovered by your research.
So it's like having circles and each time you reached the rim
of the circle, you realise there's more questions and another circle
outside it, and you go to the rim of that circle,
and you realise there's more outside it.
But you're hooked, and you just keep going.
As long as the funding, as long as life will allow you,
you just keep pursuing question after question after question.
Radio astronomy was prompting a wholesale re-evaluation
of what was held to be true about the nature of the universe.
A perfect field of study for a young scientist
with a passion for the unknown.
I was given almost complete choice of PhD topic.
They ruled out one as being not suitable for a woman,
because it involved a lot of heavy manual labour.
But I was given free range of the rest,
and Tony Hewish had this project
to identify quasars.
We discovered in 1964 that quasars,
particularly energetic radio galaxies that have compact nuclei,
twinkled in a way that ordinary radio galaxies did not.
So here was a way immediately to sort out
which radio galaxies in your survey were the interesting ones.
The project was to find more quasars
and to try and understand better what they were.
But first, we had to build the radio telescope and actually,
I spent two of my three years constructing a radio telescope.
Professor Ryle, I think
this will contradict most people's idea of a radio telescope.
I think the popular image is one of a big dish.
Yes. Well, for some problems
the big dish is the best solution, but for this particular problem
of detecting the extremely faint radio sources, we have something
which we think is better.
The telescope covered four and a half acres.
To put that in some sort of context, that's 57 tennis courts, and it had
120 miles of wire and cable in it and I was responsible for most of that.
And certainly by the end of my PhD, I could swing a sledgehammer.
I was there at the same time and I do remember Jocelyn wrapped up
in a great woolly thick jacket trying to keep warm
as they built this enormous structure in the fields of Cambridgeshire.
We were scanning the sky at intervals,
and we didn't have much in the way of computing.
This was all done with paper charts and pen recorders
and so the chart recorders rolled and the pen records came out
and Jocelyn spend a lot of time poring over these records
and simply logging every twinkling galaxy
that was detectable on the paper.
My system produced 96 feet of paper chart every day.
Great rolls of the stuff.
And then I'd take the paper charts from the observatory
from the telescope to Cambridge
to the Cavendish Laboratory, and us grad students were in an attic.
When Jocelyn would come in with the rolls of paper,
she would stand at one end of the attic, make sure that everybody
cleared their rubbish out down the middle
and she'd ball the paper rolls from one end to the other and get down
and start to examine them.
I had to scan through these charts inch by inch by inch,
looking for twinkling quasars.
I also had to identify interference,
and we had trouble with pirate radio stations.
They were just sort of blasting everything out of existence
as far as we were concerned.
RADIO JINGLES PLAY
And at one point the Home Office allocated to the East Anglia Police
our free, clear radio frequency.
So for about a week we picked up the East Anglia Police and no quasars.
You just couldn't see anything else.
'A1 hold-up, returning to base...'
After I'd been operating the telescope about a month,
I got first sight of a bit of signal that didn't look
totally like a scintillating quasar,
and yet didn't look like interference.
It only occupied about a quarter inch in the 400ft
of chart paper that it took to do a complete Sky Survey.
So I could easily have overlooked it,
but a few weeks later, analysing another piece of chart from another
survey of the sky, I noticed it again.
I got out all my previous records
from that part of the sky and found that on occasion, this curious
quarter inch of signal was there.
One key point was it had a fixed spot amongst the constellations,
so it looked a bit as if it was out there amongst the stars.
I decided to go and talk to Tony, my supervisor, about this.
'I didn't believe that it was necessarily a true recording
'at that stage.'
I mean, we've heard ships being navigated up the Thames
and all sorts of things. You know, we're in a band, a VHF band,
which is being used by all sorts of other people.
Jocelyn said, "It does appear at the same sidereal time."
That's to say it's located like a galaxy would be,
but it wasn't always there.
I mean, we were making sky surveys regularly and sometimes
when the telescope is directed in that direction
there's just nothing to be seen. But one thing was quite clear.
As I was running the system for the survey, this signal took up
this quarter inch and everything was jammed into the quarter inch
and what we needed to do was spread it out.
When you're using a chart recorder
the way you spread things out is you from the paper faster under the pen.
You make an enlargement, basically.
So all we had to do was run the chart paper faster,
and I did this faithfully for the month of November
and the object wasn't showing.
For this whole month, it appeared to have disappeared.
Tony was quite cross.
Grad students are a bit like the cat - they're there for kicking.
"Oh, it's a flair star.
"It's have been and gone and done it and you've missed it!"
But I persisted in going out to the observatory to set up the observation
and the high-speed recording, and held my breath and waited.
Then one day late in November, I actually got it.
And as the paper flowed under the pen, the pen went blip, blip,
blip, blip.
It looked like a series of equally spaced pulses
and once I was able to get the paper off the recorder,
I could see it was a series of equally spaced pulses.
That was totally surprising.
I don't know what I had expected,
but I certainly didn't expect regular pulsations.
Stars and galaxies don't pulse like that.
And that was the afternoon that I phoned Tony Hewish and said,
"Hey, Tony, this curious signal is a string of pulses."
So I said, "Well, don't be stupid.
"It has to be radio interference."
The fact that it was pulsing regularly, I mean,
was just nonsense. True astronomical sources don't do that.
I didn't argue with him.
I wasn't sure I agreed with him.
I knew somehow in my bones
that it wasn't that simple.
I learned something very useful from my time in Glasgow.
The physics students had a Physics Society and we got visiting speakers,
and quite a few of the staff would attend these meetings,
listening to the speakers. And I was the only female in the class
and the guys all asked bright questions to the visiting speaker,
and I thought, if I keep quiet, I'm going to disappear from sight.
I have got to learn to ask questions.
I was quite shy at the time, so it was actually difficult.
But I lit upon a ploy, which I'm actually quite proud of.
I realised that a speaker in the first five minutes sets out
the rudiments of their stall
and may or may not make clear what assumptions they've made.
And they then go on to build on this.
If I listened like fury for the first five minutes
and tried to spot what assumptions they had made,
you can then ask a devastating question at the end.
"You've assumed, sir, such and such and such and such.
"If that's not true, how much does it affect your conclusions?"
And the rest of the audience goes, ah!
And it works, every time.
And that was the ploy I adopted as an undergraduate
as a survival technique. Sometimes in research you can know too much,
and it's the youngster who's ignorant or somebody coming in from
outside that says, "You know, the Emperor has no clothes on",
that, actually, is telling the truth.
Can see the truth.
When I phoned Tony that first afternoon to say, "Hey, Tony,
"you know that funny new source?
"It's pulsing with a period of one and a third seconds."
Tony knew more astrophysics than I did, and he knew that it meant
that that object was very, very small, star-sized.
Until then, radio astronomers hadn't seen strong signals from stars.
They didn't believe stars were radio sources, so there was a problem.
I knew less astrophysics.
I wasn't bothered about the object's size. I thought, "interesting".
There was no denying the existence of the mysterious pulses,
but were they real or simply an experimental artefact?
A fault in her telescope?
One of the first things we wanted to do was see
whether it was some fluke of my equipment,
and I was afraid that literally I had got some wires crossed
or done something stupid like that.
And so we enlisted the help of Robin Collins and his supervisor Paul Scott
to see if their radio telescope could pick up this pulsing signal.
The way the telescopes were aligned,
my telescope looked at that bit of sky shortly before theirs did.
20 minutes or something.
We could see it pulsing nicely with my telescope
and then we went and stood by Robin's pen recorder.
And we stood by this pen recorder,
and waited and waited and waited...
and nothing happened.
Oh, my God.
Tony and Paul, the two academic staff,
started walking down this very long laboratory and I was padding along
behind them trying to keep up with them, in every sense of the word.
Robin stayed by the pen recorder
and we'd just got down the end of this long laboratory,
and there was a strangled cry from Robin, "Here it is!"
and we came charging back up the lab
and there it was - pulse, pulse, pulse, pulse, pulse, pulse.
We had actually miscalculated when it would appear in Robin's telescope
and we had been out by five minutes, or so.
Fortunately, only five minutes. If we'd been out by a longer interval,
we might have given up and gone home and the story
would've been very, very different.
I'm waiting for an intelligible message from space and here is one!
Is it intelligible? Yes!
You can decipher it? Oh, do you think the cosmos is inhabited
by a load of boy scouts sending Morse code?
What is this, Dennis? Is it a message? Have a look. Let me see.
Could be from a distant probe.
Or another planet.
Yes.
I remember talking to a very learned friend, Sir Edward Bullard,
a famous geophysicist.
I said "Look, we're getting this very strange signal, seems to have
"fixed co-ordinates in the sky, but it's a series of regular pulses".
And of course the question mark
was in our minds too, could it be intelligence or something?
He said, "Simplest explanation -
"look and see if it's a single frequency
"and then it's probably 99% an intelligent signal".
You know,
radio signals naturally emitted
cover a whole broad range of radio frequencies.
But it's intelligent things that radiate on a single frequency.
And that's what it turned out to be...and the intelligent signal
became more real. Things were all getting rather tense at that stage.
I went down to Tony's office late one evening to ask him
about something, and rather unusually, the door was shut.
Tony normally had an open door policy.
So I knocked, and a voice said, "Come in", and I poked my head
round the door, and Tony said "Ah, Jocelyn, come in and shut the door."
And there was a high-level meeting going on in there.
There was Tony, there was Martin Ryle, the Professor, the head
of the group, and one other senior person and it was a discussion
that I think I should have been in on, actually, from the beginning.
We thought this was bigger than we want to handle ourselves.
We don't want to just give it to the press, this has to be done properly.
And I discussed this with Martin Ryle because I was wondering what to do...
and he was half joking, but he said, "Burn the records, and forget about it".
Because he said, "If the news gets out
"that there's intelligence...
"out there, what is going to happen"? People will want to launch
a signal in that direction, to talk to them or something,
and he said, "Supposing all they're doing on that distant planet
"is looking for a reply somewhere,
"so if they, they're overcrowded,
"they're looking for a nice, young, green planet that they can occupy,
"that's what it's all about, and the next thing is, you'll be invaded".
We didn't solve it that evening
and I went home to get supper, and I was really getting pretty cross.
My money was running out, I wanted to get a thesis done, get my PhD
and there was some silly lot of little green men choosing
my radio telescope and my frequency
to signal to earth, you know, how dare they, kind of thing.
I got some supper and felt I had to come back to work.
With all the special observations on the pulsars, the twinkling quasars
had been rather neglected and there was a huge backlog of these
survey charts to be analysed...
and at about quarter to ten at night I was analysing a chart
from another piece of sky and thought I saw a piece
of this scruffy kind of signal.
Looked exactly like what I was seeing before, but from
a totally different bit of the sky.
Right. I thought, I'm not going to bed tonight,
I'm going out to the observatory.
That bit of the sky was due to go through the telescope beam
at 2.00, 3.00 in the morning...
December 21st, perishing cold.
And I switched on the high-speed recorder and it came,
blip, blip, blip, blip. Clearly the same family.
The same sort of stuff.
And that was great. That was really sweet.
It finally scotched the little green men hypothesis,
as it's highly unlikely there's two lots of little green men,
opposite sides of the universe,
both deciding to signal to a rather inconspicuous Planet Earth
at the same time, using a daft technique and commonplace frequency.
It has to be some new kind of star not seen before.
And that then cleared the way for us publishing, going public.
Martin Ryle called up the editor of Nature, John Maddox,
and more or less said, "We've got something interesting coming".
He didn't quite say "hold the presses" but he nearly did.
Now the people here say that if they got three signals as exactly spaced
as that, it would be very unusual.
If they got four, it would be phenomenal.
Well, they've had pulses as exactly spaced as that,
24 hours of the day since November.
Well, these signals that we're picking up are entirely new.
Nothing like this has been seen in radio astronomy before.
The excitement was because this was a totally unexpected,
totally new kind of object behaving
in a way that astronomers had never expected, never dreamed of.
Here is a discovery which illustrates the Universe
is far more complex than we at present believe.
That month, that was a real high point...
and when I wrote that Nature letter,
I thought, my God, that's pretty good actually. Ha, ha, ha!
There's a lot in there. Yeah.
Seeing the article in print was tremendous.
And I remember sending a copy of the paper to my physics teacher.
And that's your physics teacher at the Mount? At the Mount, yes.
My physics teacher at the Mount.
And how did he react to it? He had actually alerted the school.
There was a lot of publicity,
Mr Tillett had seen this and told the school.
There aren't so many people that take up physics as a profession and
certainly relatively few women of my generation, so Mr Tillett followed
with some interest my career.
And I was really pleased that he was still around
at the time of the discovery.
The family was just...amazed.
Absolutely.
And proud? Very proud.
Despite the obvious importance of Jocelyn Bell's discovery,
the mysterious bursts of energy still hadn't been named.
We hadn't really thought of a name for these things, so this journalist
who was from the Daily Telegraph said, "What about 'pulsar',
"as an abbreviation for Pulsating Radio Star"?
And he wrote it up on the board in the office where we were meeting.
And we looked at it and thought, "Oh yeah, that looks OK".
If only a very few pulsars have been discovered so far,
and they are all very close to the sun, comparatively speaking,
does this mean there are vast numbers of them throughout the galaxy?
Yes, if they're distributed throughout the galaxy in the way
we find them close to the sun,
there must be millions of them in our own galaxy.
And of course, the most important question of all, what are they?
Well, we know that they're very small, they're objects
about the size of a planet.
We know also that they're very energetic and that the source
of energy must be far greater than a planet could really provide.
Something like a star, compressed into a volume the size of a planet.
To work out what pulsars are,
we had to go back to exploding stars, the supernovae.
It used to be assumed that a supernova was a total catastrophic
destruction of the star, with everything dispersing out into space.
However, in the 1930s, an astronomer,
a Swiss astronomer called Zwicky, a guy who had a lot of ideas,
a very creative mind, reckoned that when these supernovae occurred,
the core of the star got shrunk right down to make this very dense ball,
and it would be rich in neutrons, so it was called a neutron star.
Neutron stars were a pretty wild idea,
nobody took them very seriously,
and I don't know that people took Zwicky very seriously either.
But we now know, following the discovery of pulsars, that there are
these objects left behind, because it turns out that the pulsars are indeed
neutron stars, and Zwicky was right.
This is what we believe the neutron star will look like.
The neutron star is an incredibly compact thing.
These lines show you the direction of the magnetic field
close to the neutron star.
They've a very strong magnetic field, perhaps a million, million times
the Earth's magnetic field...
And it seems that coming from the magnetic north and south poles,
there's a beam of radio waves.
And as the star spins, this beam gets swept round the sky
like a lighthouse beam...
and each time a beam sweeps across the Earth, we see a pulse.
So if you get a pulsar going four times a second,
it means it's spinning four times a second.
If you get a pulsar 600 times a second, it's spinning 600 times
a second, which beggars imagination, but that's what seems to be the case.
The faint blips from space so nearly dismissed as error
took the world by storm.
And any astronomer worth his salt wanted a piece of the action.
Observing pulsars is like listening to a Beethoven symphony.
There's the rhythm of the pulses themselves,
and within the pulses, a complicated pattern of notes.
Sometimes at one frequency,
sometimes at another, just as in the melody of a musical composition.
All of a sudden, people went from thinking about stars
as being unchanging, the Universe being relatively dull and boring,
to suddenly, the Universe is full of these things flickering
and flashing around, extremely energetic, very exciting.
Pulsars were important but they were an enabling discovery, because
it actually showed that not only did these ideas exist theoretically,
but they could actually be seen
and it allowed us to tie down many of the theoretical ideas
that were in vogue at the time.
Stephen Hawking got on to me and said how delighted he was, congratulations
and so on, and he said, "Well, if neutron stars exist,
"you must believe strongly in black holes".
"I mean, a neutron star is so close to being a black hole,
"that if neutron stars are there then there's no question
"that black holes are there too".
It's all do with the mass of the star that's collapsing.
If the star is about the size
of the sun, it's going to form a white dwarf, where it's held up
by the pressure of the material inside it.
If the star is more dense, it actually will form a neutron star,
where the neutrons themselves are the thing providing basic pressure.
If there's even more mass, the neutrons themselves
aren't strong enough to hold up
against gravity. The star collapses further and you get a black hole.
I mean, black holes were a bit of a joke in those days.
You know, Steven Hawking was making these outrageous suggestions,
and so on, and people didn't take black holes at all seriously.
But I think after that, they did.
Like many scientific discoveries, it took an open-minded researcher
to realise there was something there to be discovered.
It was a quality which had been instilled in Jocelyn Bell Burnell
from an early age. I was born into a Quaker family.
My son, who's done the research, says I am ninth-generation Quaker.
I've been active in Quakers all my life, and still am.
I find that Quakerism and research science fit together very very well.
In Quakerism you're expected to develop your own understanding of God
from your experience in the world.
There isn't a creed, there isn't a dogma.
There's an understanding, but nothing as formal as a dogma or creed.
And this idea that you develop your own understanding also means that you
keep redeveloping your understanding as you get more experience.
It seems to me that's very like what goes on in "the scientific method".
You have a model of a star, it's an understanding,
and develop that model in the light of experiments and observations.
And so in both, you're expected to evolve your thinking.
Nothing is static. Nothing is final.
Everything is held provisionally.
Through history, we have seen some theories
that have stood the test of time well and some that disappeared quickly.
A theory that stands the test of time well will have been prodded
and poked and battered and examined from every angle and still stands up.
and Einstein's theory of relativity is one of those that's been subject
to a lot of scrutiny, but it was only following the discovery
of pulsars that it was possible to test Einstein's ideas about gravity.
Einstein's theories predict that where you have a pair of stars
orbiting each other, this system produces a new kind of radiation,
gravitational radiation, or gravitational waves,
and the effects of these waves being produced are that the two stars move
closer together and go round faster, which sends out more gravity waves,
so they move closer together and go round even faster,
and they actually end up merging.
With the first pulsar discovered in one of these binary systems,
they've been able to track the orbit and they have seen that the stars
do move closer together, in exactly the manner predicted by Einstein.
So does that mean that Einstein's been proved right, then?
The current situation is that the pulsar astronomers have
shown that Einstein's theory of gravity is right to about 0.02%.
That's not the same as saying it's true though, is it?
Scientists should never claim that something is absolutely true.
You should never claim perfect or total or 100%,
because you never, ever get there.
Is science therefore not a quest for the truth?
Science is a quest for understanding.
A search for truth seems to me to be full of pitfalls.
We all have different understandings
of what truth is, and we each believe or we're in danger of each believing
that our truth is the one and only absolute truth,
which is why I say it's full of pitfalls.
I think a search for understanding is much more serviceable to humankind
and is a sufficiently ambitious goal of itself.
Jocelyn Bell Burnell has devoted her life
to the search for understanding.
After completing her PhD, she settled into the world of academia,
continuing her research into the behaviour of stars.
I have very vivid memories
of October 10th, 1974.
I was working with a satellite called Ariel V that was launching
from off the coast of Kenya on the morning of 10th October.
At about 12.05 that morning, one of my colleagues came steaming
into the office, "Have you heard the news?!"
No, John, what news? Something wrong with Ariel V?
"No, the Nobel Prize."
His wife had been listening at home to the news and had phoned him up
and told him Martin Ryle and Tony Hewish had got the Nobel Prize.
And John was along, I think,
hoping to see steam come out of my ears.
Well, that was just a total, huge surprise.
I just hadn't the faintest idea it was going to happen like that,
and to get it with Martin Ryle was a double pleasure,
because he was a wonderful man, and the sadness was that he wasn't able
himself to go and collect the prize.
Professor Antony Hewish.
The discovery of pulsars, for which you played a decisive role,
is a most outstanding example of how, in recent years, our knowledge
of the Universe has been dramatically extended.
It just is a wonderful experience.
TRUMPET FANFARE APPLAUSE
Other people were annoyed on my behalf, it has to be said.
And there were puns about "No Bell",
punning on my maiden name, Bell, the "No Bell Prize".
I was slightly saddened that Jocelyn Bell has not received an equal...
recognition of her contribution, which I think was central.
And I think it was, there were many people who felt it was rather sad,
and that perhaps she should have been up there with the others.
There was some disappointment about that at the time.
I mean, my analogy really is a little bit like...
when you plan a ship of discovery and you go off...
and somebody up the mast head says, "Land ho..."
That's great, but I mean,
who actually inspired it, conceived it and decided
what to do when, and so on.
I mean, there is a difference between skipper and crew.
To be honest, I don't think it would have mattered who'd been my student.
I mean, it was a serendipitous discovery, because such a piece
of equipment had been set up.
I mean, the discovery of pulsars was unavoidable
once that survey had begun.
Serendipity is very important,
but I think you shouldn't exaggerate how important it is.
It would have been very easy for Jocelyn just to simply ignore that
and put it in the not-interesting bracket interference box...
but she didn't do that.
What Jocelyn had done was recognise that there was something happening,
and happening in a repetitive manner
I suspect that perhaps only one in 100 people,
given the same circumstances, would have spotted it.
It's not as though it's something that everybody would spot.
She kept, I think, perhaps more meticulous records than probably
her supervisor might have expected about what was going on.
And I think that they provided the core evidence that really drove
the whole discovery of pulsars. So yes, she was lucky she was there.
But if she hadn't done it, it may have been many years before anybody
got round to it seriously.
One of the questions it's always interesting to ask
is why weren't pulsars discovered earlier?
And in fact, they were seen earlier,
but not recognised.
And there are a number of stories around about people who saw pulsars,
but didn't realise what they were seeing and didn't follow it through.
The earliest one I know comes from the late '50s, I believe,
at an optical telescope which was open to the public
and the telescope was trained on that funny star in the middle
of the Crab Nebula known as Minkowski's Star.
A young woman stepped up to the telescope and said,
"That star's flashing." Elliot Moore, the professional astronomer,
who was on duty that night, explained to this woman, you know,
that stars scintillate, twinkle.
She said, "I'm a pilot, I hold an aeroplane pilot's licence,
"I know about scintillation, twinkling...that star's flashing."
Now the pulsar in the Crab Nebula,
which is what Minkowski's Star actually is, flashes 30 times
a second, which is very very fast, and a lot of people can't see that.
But actually, some people can.
I think she probably did see it and I think Elliot Moore believes she did,
but it wasn't followed through, it wasn't published, it wasn't recorded.
What's happening with it now?
The girl who started all the fuss about the pulsars, Jocelyn Bell.
Our picture of how science is done has changed markedly.
The picture used to be that there was a senior man, it always was a man,
who had charge of a whole team of people.
And the people in the team weren't expected to think,
they just did what the boss told them. And if that is the true picture
then it's quite fair that the boss takes the blame or the credit.
But these days we have a different picture.
We have much more a picture of a team of people working together,
each contributing from their own strength, each adding ideas,
a much more egalitarian picture.
I think when I was a grad student
that was actually what was happening but in an unrecognised way.
We were still in the old 1920s, 1930s picture.
Although that wasn't really what was happening.
It's almost like it was the intellectual property
of the university and therefore it was the heads of department
who were recognised for it.
She is remarkably calm and unbothered about it and...
doesn't make a fuss about it at all.
You can actually do extremely well out of not getting a Nobel Prize.
I have had so many prizes and so many honours and so many awards,
that I think I've had far more fun than if I'd got a Nobel Prize,
which is a bit flash in the pan. You get it, you have a fun week,
and it's all over and nobody gives you anything else after that
because they feel they can't match it.
For Jocelyn Bell Burnell,
the real enemy of science is not the allocation, or otherwise, of prizes,
it is the belief that science can arrive at an ultimate truth.
There are people around, I think,
who believe they have got there, believe they understand it all
and they're no longer open to new experiences,
new ideas, new revelations.
I don't think you should be so closed.
If we assume we've arrived, we stop searching.
We stop developing.
Professor Dame Jocelyn Bell Burnell
has enjoyed a hugely successful career.
She has gone from being "the girl who discovered pulsars"
to recognition as one of the outstanding scientists of our time.
Though she has played a significant part in our greater understanding
of the Universe, she insists there is still some way to go in telling
the complete story of the Cosmos.
I can see a number of important issues facing astronomers today.
There are questions about the future of the Universe.
We believe we understand that the Universe started
with what we call the Big Bang, 13, 14 billion years ago...
and that it's been expanding ever since.
One of the things we have recently discovered is that the expansion
appears to be getting faster, which is totally counter-intuitive.
You would expect the gravity between the galaxies to actually
be slowing the expansion, and it's not, it's getting faster.
Something is acting to oppose gravity.
Something is pushing the galaxies apart, faster and faster
and at the moment we have very little clue what that is.
We call it dark energy, but that doesn't actually tell us
what it is, it's just a label.
It is hard to understand. I'm not sure how we're going to make progress
on that one, but it's something that a lot of people are fascinated by.
Looking at the Universe as a whole cosmology, the birth, life
and death of the whole Universe...
We used to have a nice, simple model.
Then we added things like dark energy. And our nice, simple picture
is getting messier and messier and messier.
I have this sense that we need to picture cosmology, the evolution
of the Universe, in a whole new way.
I'm probably not one that can achieve this new thinking.
Somebody will, and at the moment, we are waiting for it to happen.
A bit like a pregnant pause.
A bit like what happens when there's a snowfall, first snowfall
of the year, and everything goes quiet, and kind of waits.
I feel we're in that sort of phase.
Nothing is static.
Nothing is final.
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