In the last hundred years,
our understanding of the universe has advanced far further
than in previous centuries.
We have discovered that the universe
and time itself had a beginning fifteen billion years ago.
There was a cosmic explosion of energy, called the big bang.
The energy produced all of the matter in the universe,
from stars and galaxies to our own planet,
and even ourselves.
Yet one guestion still needs an answers: How did the big bang begin?
We need to know the laws that held at the moment of creation,
when the universe sprang into existence.
Are these initial laws over and above the laws
that tell us how the universe evolves?
Or is there a theory of everything that governs the universe at all times
and determines how it begins and develops?
Atlantic City is a giant playground.
But for many,
the fading attractions of old Atlantic City are less fascinating
than the uncertainties of its modern casinos.
Sidney Coleman knows it's the same with physics
Physics starts out by trying to explain the sort of phenomena
that occur in everyday life - balls bouncing
and planets grounding around the sun, and all that stuff.
And that's also pretty much the sort of stuff that,
er, you encounter in everyday life,
and your tacit assumptions about those things
and how they behave are deeply embedded in the language of everyday speech.
That's how the language of everyday speech developed.
But physics has now probed beyond the familiar.
Theorists like Sidney Coleman spend their days
making long imaginary journeys into strange worlds,
far removed from everyday life.
As physics develops and physicists want to find out more and more,
they try and understand physics which reveals itself
only under extreme conditions on the inside of an atom,
in a high-energy accelerator,
in a guasar, at the, during the beginning of the universe
Now it would be really remarkable
if the concepts of everyday speech continued to be valid
when we extend the universe of study so enormously.
It's only natural that,
as we get farther and farther from everyday experience,
the theories we have to describe all this new stuff,
in addition to everyday experience,
should look less and less intuitive.
Why should your intuitions have developed to be good inside a guasar?
Your ancestors did not spend any time inside guasars.
So, things seem to get,
from our viewpoint,
our earth-bound viewpoint, stranger and stranger.
One thing we now accept is that the universe is expanding.
But if it is getting bigger with time,
then it must once have been very small.
When you trace the evolution of the universe backwards in time,
you inevitably find yourself being pushed towards the physics of the very small.
This small world has its own strange language.
And it's at this scale,
millions of times smaller than a single atom,
that the universe must have begun.
The study of these subatomic particles is called guantum mechanics.
Two foundation stones,
really, on which we've built the current modern picture of the universe
and the matter in it are guantum mechanics and general relativity.
Einstein was instrumental in both of those theories,
he was a founder of guantum theory and the sole inventor of general relativity,
and the picture that they give us of the universe is,
is a very good one,
in the sense we can make a lot of predictions
and explain a lot of phenomena,
er, but the picture is really only partial in many ways,
and one of the problems is that the two theories,
in fact, don't fit together.
Einstein's theory of general relativity
describes the large-scale universe we see today.
Quantum mechanics describes the behaviour of things smaller than atoms.
As small as the universe was when it first formed.
A complete description of the universe has to embrace everything,
from the tiniest particle to the largest galaxy.
The two theories have to match up.
Einstein believed that he could find a way to make them fit,
Because the methods that he had applied to problems in physics
before had always worked,
he'd been very successful in unifying things,
he trusted his instincts,
so his instinct was that there should be a theory
which described the two theories together.
At the time,
Einstein was the only one thinking that the two theories could be unified.
Isolated by the scientific community, he worked on.
He spent decades on this work.
He worked, basically, alone,
I think that no-one else shared his view,
er, that this was the way to go, in unification.
So he was very solitary,
and he was working by himself up until the day he died.
When Einstein died, in 1955,
half-finished notes describing a theory of unification were discovered by his bed
He had failed to achieve his dream.
But Einstein was ahead of his time.
Forty years later,
the importance of his lone guest has become recognised.
Now, theorists everywhere are searching for a single eguation
to describe the workings of the entire universe
What they want is a theory of everything.
At the beginning, the universe is a central point.
The next instant, it is enormous.
To understand this properly,
we need a theory of everything,
which is still just beyond our grasp.
However, we already have some ideas
why the expansion of the early universe was precisely what it was.
There are already a number of mathematical eguations
which begin to describe how the universe must have grown.
They have been carefully built up from the evidence we've now glimpsed
Of what conditions in the early universe must have been like.
It is only by constantly matching theory and observation
that a clearer picture can emerge.
Giant particle accelerators,
such as SLAC, in California, smash atoms into each other.
These explosive collisions create energies, temperatures,
and pressures which can be measured.
The same measurable conditions must have existed in the early universe.
In the 1970s,
scientists began to tackle the unbelievable mathematical balance
necessary for our universe to exist.
What was always needed, and nobody had really pointed this out,
was that you had to assume that the expansion rate of the early universe
was tuned almost exactly right.
That is, almost exactly the right expansion rate
so that the universe would be just on the verge
of eternal expansion versus eventual collapse,
er, if one talks about the universe at a time
of about one second after the big bang,
er, this tuning,
this precise fixing of the expansion rate had to be done to an accuracy
of about fifteen decimal places.
If the universe just expanded one part in the fifteenth decimal place
faster than we thought it had,
it would fly apart without galaxies ever having a chance to form,
er, if the universe at one second after the big bang were.
Expanding with one number less in the fifteenth decimal place
than what we thought,
then the universe would collapse
before galaxies had ever had a chance to form.
To make the universe work,
the universe had to be perched just on this borderline
Guth was puzzled that our universe should be the product
of such a magical eguilibrium,
slowly growing in perfectly balanced expansion
for the last fifteen thousand million years.
Alan Guth had managed to grapple with mathematics of extraordinary complexity.
Yet, in many ways,
what he was really doing was responding
to the simple intuitive guestions of a child.
When I was still a kid,
I asked myself the guestion,
well, how would it happen
that in different parts of the universe expansion started simultaneously?
Who gave the signal?
How can I understand it?
And then I thought that maybe when I will grow older I will open the books
which are written by clever professors and I will find out the answer.
When I grew older,
I found that people did not know that the guestion exists.
Unknown to Alan Guth,
a Russian called Andrei Linde was also tackling the problem
of expansion in the early universe
During the last fifteen years we've learned the guestion can be answered.
Linde now lives in California.
But in the 1970s,
he and Guth were working on opposite sides of the world,
on an idea that came to be known as 'inflation'.
So, would you give me a glass of water.
Inflation suggested a way for the right kind of expansion.
Lf, somehow, energy could be trapped in a vacuum,
it would naturally expand like a number of bubbles being,
released all at once.
Perhaps these bubbles could join up together
and rapidly expand as one vast bubble,
producing all the symmetry needed for our universe to grow smoothly
and guickly expanding evenly in all directions.
Linde, in Moscow,
and Guth in California guite separately had the same inspiration.
They needed to do detailed calculations to see if the idea worked out.
In 1979, on a December evening,
Guth opened a notebook and started to write.
I had not yet calculated everything through that night,
enough to convince myself that it was fascinating idea
and that it would probably work.
The next morning I raced back to SLAC,
and actually I kept track of my personal biking records to SLAC,
and I set a new record that morning,
er, once I got there
I whipped out my notebook and started continuing the calculations,
and by, I guess, the end of the morning,
I convinced myself that it did fit together.
Andrei Linde had also started his own calculations.
But as he worked through the detail,
it seemed as though inflation theory couldn't actually work in practice.
In California, Guth encountered the same problem.
As I continued to work on inflation,
I did however discover that there was a serious problem in the way
that inflation finally ended.
It happened just like water boils,
a bubble would form here,
a bubble would form there,
the bubbles would grow and collide,
and form an incredible morass of matter with tremendous non-uniformities in it.
We look at,
in fact, nothing whatever like our universe looks like.
This was a serious problem that clearly reguired modification.
Thank you.
You're welcome, Sir.
But Guth went ahead and published his theory.
Even with its flaws, inflation caused a sensation.
But Linde was worried when he read Guth's paper.
He felt he had to find a solution to the theory's imperfections,
to give inflation respectability.
I don't know whether you know or not,
but I had an ulcer,
which was induced by the work,
in some sense, because when I heard about all these ideas,
er, and I, I was really literally thinking in these terms
that God could not be so stupid to lose this opportunity to make the world,
er, in such a economical way,
and when I found a solution, the ulcer has gone.
Well, er, so sometimes physics help.
Linde's new idea was simple.
What if just one bubble of energy inflated all by itself into our universe?
It was about eleven at night,
and I could not keep myself from,
well, this feeling of happiness and I came to my wife and eventually awake her
and I told her,
look, it seems that I know how our universe could have emerged.
I first announced it,
new inflationist scenario,
at, in the meeting of guantum gravity in Moscow,
which occurred in October '81, and at that time,
many very good physicist in Moscow,
and the star of the meeting was Steve Hawking.
I gave a seminar with Andrei translating.
When I said there was a difficulty with Guth's idea of bubbles in collision,
Andrei said that the whole universe could be a single bubble.
I objected, because the bubble would have been bigger
than the universe at the time.
In the middle of his talk,
he told that, well,
there was a very interesting idea of Andrei Linde recently
this was just my talk the previous day,
and I was all my head in it's translating it,
and then he says but but this model,
this idea does not work, and let me explain why.
And he start talking and talking
and I'm translating it,
and for a half an hour,
in the face of all the institute,
I was explaining them why new inflation just simply cannot work.
In front of his Russian peers,
Linde's new theory had been demolished.
But he was determined to continue the debate.
And then I asked him,
would you like to actually to understand the details of this,
and he told me, sure,
and then we disappeared for two hours,
all the institute was trying to catch Steve everywhere,
and the famous physicist disappeared,
the whole institute was in panic.
Linde and Guth had given us an important idea.
Inflation accounts so neatly for the way the universe has to expand.
I'm sure it must be part of the final picture.
But inflation by itself does not explain the start of the universe
We still need a theory of everything for that.
But in applying the theory to the beginning of the universe
would be difficult, because my own work had shown
that the eguations would break down at the big bang.
You can take Einstein's eguations and run them backwards in time,
not for a real universe,
which is awful complicated,
full of lumps and irregularities,
but for a simplified model of the universe,
where matter is,
distributed smoothly and uniformly throughout the universe,
and when you did run it backwards in time, you found,
eventually, there was a point in which everything came together at a single point
where gravitational fields became infinitely strong,
energy densities became infinitely high,
technically we call it a singularity.
The universe at its birth needed to have some fluctuations in density
and velocity to enable particles to be formed.
But the maths of the singularity won't predict any such fluctuations.
In fact, they won't predict anything at all.
What happens at a point of singularity becomes a matter of pure speculation.
Physicists like to solve eguations,
they like to say, if this is the way things are now,
this is the way they'll be a year from now.
Once you hit a singularity,
you can't do that,
the eguations blow up and you don't know what to do with them.
This is disturbing, people don't like singularities.
The best bet for solving the problem looked like being guantum mechanics.
Quantum mechanics is probably the strangest thing human minds
have ever thought up.
I think if a thousand philosophers were to work for a thousand years,
trying to think of something of maximum strangeness,
they wouldn't have thought up anything as strange as guantum mechanics.
At the heart of guantum mechanics is the idea of chance.
It's called the uncertainty principle.
If a subatomic particle isn't moving,
it's too small to detect.
But there are ways to trace the path of a moving particle.
You can never find out with precision where anything so small really is,
but you can have a very good idea of its probable position.
This probability,
the principle of uncertainty,
does seem to work.
Strange as it is,
it is apparently the way the universe works,
that enables us to make predictions
about all sorts of processes involving atoms or elementary particles colliding,
that are verified by experiment to amazing degrees of accuracy.
The problem is that these laws of uncertainty only seem to make sense
of the universe at its moment of creation.
They can't be applied to the big universe we now experience,
a universe described with incredible accuracy
by Einstein's theory of general relativity.
A lot of people have been trying to combine guantum mechanics
with gravity over the years,
a guantum mechanical replacement or Einstein's general relativity.
I wanted to resolve the problem of the singularity.
After all, I was largely responsible for raising it in the first place.
Maybe one could choose a path around it.
Hawking saw that the uncertainty that came
when you tried to combine guantum mechanics
and gravity was in fact as escape route,
and can be used to get away from the,
avoid the singularity problem,
which he himself had done so much to raise.
In a remarkable paper,
done in collaboration with James Hartle,
er, Hawking was able to solve a very,
very simplified model of the universe
Jim Hartle and I showed how a universe like our own
could be born without the troublesome singularity.
It involved the use of what is called imaginary time.
This may sound like science fiction,
but it is a well-defined scientific concept that science fiction borrowed.
The idea was that in imaginary time,
the universe has no boundary,
no beginning or end,
it just curls round on itself like the surface of the earth.
It was a complete guantum mechanical description of everything
that could be said about this simplified model of the universe,
and it had no singularities.
It's possible that guantum mechanics is the answer
to the problem of the singularity.
I have to make it clear that the no-boundary universe
is just a proposal, but it has some interesting implications.
Without boundaries, the universe has no beginning and no end.
We don't have to explain its creation.
The universe simply exists, but the conseguences of the no-boundary proposal
cannot be worked out fully without a complete guantum theory of gravity
that will unite general relativity and guantum mechanics.
We are back to the search for a theory of everything
In 1985, a new theory emerged,
which raised hopes that the search might soon be over.
You're tuned to WBAI, 99.5 FM,
on your dial,
coming up next - Explorations with Dr Michio Kaku.
Welcome. This is Exploration.
This is Dr Michio Kaku, Professor of Theoretical Physics,
and this is a programme devoted to science
and the fantastic discoveries as we explore the universe Now,
of course,
superstring theory,
the theory that will perhaps give us an explanation for the entire universe.
Some people say the instant of the big bang,
the universe was a dot.
The new picture is that it's like a bowl of noodles,
a bowl of noodles where we have thousands and millions of little strings,
vibrating at the instant of time,
that exploded,
creating the enormous diversity of matter and energy that we see around us.
Superstring theory is so bizarre,
so strange,
that we were not destined to see this theory in the twentieth century.
Many of us believe that it's really twenty-first-century physics
that fell accidentally into the twentieth century.
It was discovered by accident,
a fluke.
A mathematician was reading up on topology when,
guite by chance,
he noticed an eguation which described the behaviour of a particle.
Then he found another, describing gravity.
Could this branch of maths contain within it the theory of everything?
So we have two great theories of physics,
the theory of the very big,
Einstein's theory of relativity,
and the theory of the very small, the guantum theory.
And these two theories don't like each other,
they are incompatible, one is smooth, beautiful, like marble,
and the other one is coarse and grainy, like wood.
And to get them to,
to meet together has been the object of the last fifty years
of intense investigation.
Today, we think we have it.
We think we have the superstring theory,
which is perhaps the most fantastic,
the most marvellous theory ever proposed in the history of science.
After years trying to connect two incompatible theories,
now there was a radical new candidate,
based on tiny magical strings.
Strings are extremely tiny,
like a hundred billion billion times smaller than a proton,
so let me explain.
Take a atom, and expand it to the size of the solar system.
If the atom were the size of. Our solar system,
then a string is much smaller than that, a string is the size of an atom.
That is how incredibly tiny this all is.
We also think that once upon a time the universe was the size of a string
When stings move, they vibrate.
They force the space around it to curl up, to bend,
exactly as Einstein had predicted.
Now the guestion that scientists had grappled with
since Einstein seemed as if it was about to be answered.
With string theory,
it looked like there was no difference between the worlds
of the big and the small.
We physicists have been puzzled by the fact that we have matter,
like atoms, and we have forces,
like, er, like gravity,
that, that attract atoms.
Now we realise that this dichotomy between force
and matter is really not a dichotomy at all.
These are nothing but vibrations of the same string.
One string that vibrates could be a guark,
another string that vibrates could be an electron.
But yet another string that vibrates that vibrates could be light, a photon,
or Einstein's theory of gravity.
But the full potential of string theory is still unknown.
It seems to offer answers,
but the eguations also create a new set of guestions
guestions that at the moment we can't answer.
These eguations are well defined,
they're well known,
but some people think that perhaps
we humans are not smart enough to solve them.
Think of a duck, or, or,
er, a monkey, why should a duck or a monkey understand
calculus, or electric fields, or black holes?
And why is it that we have the power to understand the big bang
and the black holes?
And then the guestion is,
are we smart enough to understand the theory of everything?
At the present time - no.
By the end of the eighties,
I and a number of other physicists were beginning to wonder
if string theory really was the ultimate theory of the universe
One problem was that there were five different string theories.
So much for a single theory of everything.
The American cosmologist Lee Smolin took a lonely step back from physics.
He wondered if we were looking for the wrong thing.
Why should the answer to the universe be contained in a mathematical eguation?
The hope behind string theory originally was that there would be one simple law
which would have a unigue solution,
which would explain how the, universe is,
the history of the universe, and so forth,
and that hope that all the guestions would be answered
in a single law is what has not happened in string theory.
It was thinking about this,
at the same time I was reading about biology,
er, that led me to begin to wonder
whether the answers to some of the guestions
in elementary particle physics did not rest in a single unigue theory,
but maybe would be a result of historical accident,
and maybe there could be a process by which,
through a series of developments in the early history of the universe,
somehow the universe chose what its parameters were.
The wonderful thing about the biological world is
that it's so complicated.
There are so many different species,
they're so beautiful in so many different ways,
and one would think that one could not possibly explain this,
which is of course what people thought before Darwin.
What Darwin discovered is that there is a rational way to understand
how such enormous variety and complexity can come to be in the natural world,
without being put there in the first place,
and the basic idea is that you have some population,
which can reproduce itself,
that when it does so,
there are small random changes in the characteristics,
and that these characteristics lead to differences
in how well the creatures survive.
Could Darwin's idea of natural selection somehow be applied to our universe?
If one studies astronomy on scales much,
much larger than the earth,
for example, the disk of a spiral galaxy,
one discovers it's a complex self-organised system,
somewhat akin to biology on a much simpler level.
It turns out that The new possibility
which Darwin gave us is that a system can have all the beauty
and variety and complexity of our world.
And be assembled from itself,
that it can organise itself over time.
What twentieth-century science is leading to is,
in my view, I mean, of course could be wrong,
the culmination of this view of the universe
as something which does create itself and assemble itself.
In Russia, Andrei Linde was also.
Thinking about evolution.
But his thinking stayed rooted in physics,
as he tried to perfect the inflation theory It wasn't proving easy.
Russian politics were affecting his health and his work.
85 was the first year of perestroika,
so the first year of perestroika Gorbachev
just came to power and they started reconstructing everything,
which is a translation of the Russian perestroika,
the reconstruction, and as a first step,
they completely forbidden us to send our papers abroad,
so I have a feeling that I am living with my mouth shut,
I cannot tell others what I am doing, and this was pretty depressing.
So it became so much depressing the actually I became simply ill,
and now I was lying in the bed for about a month and a half,
and then, all of a sudden,
there was a call from Academy of Sciences,
and they told me that I must go to Italy
to give some popular lectures on astronomy,
and I told them, I am ill, I cannot go.
After years of repression,
suddenly Linde was free to say what he liked.
But he only had twenty-four hours to think of a new idea.
After this year with the mouth shut,
they are suggesting me that if I do something,
then tomorrow it will be sent there
by diplomatic mail without any approvement,
without any signatures, without any of these bureaucratic work,
tomorrow it will be in Italy.
On the other hand, it can,
it must be done just immediately, and, and I am really sick,
I just cannot think, I, I took my head like that and I started,
what can I invent within half an hour
or so I will write it today in the evening
and tomorrow I'll sent it to Italy,
what can I do within half an hour?
And within half an hour,
I have got a theory of self-reproducing universe.
In Linde's new theory,
inflation does not take place in a bubble at all.
Instead of one universe growing,
his eguations predict that there have to be many.
All will be different, and all will have their own big bang.
In time, they will seed other universes,
so the process goes on for ever.
It's a purely theoretical proposal,
build from Linde's earlier imperfect ideas of inflation
Out of depression had come inspiration.
And since that time I did not have such a depression,
which in a certain sense may be unfortunate.
Smolin and Linde's evolutionary theories have failed to catch on.
Most cosmologists, like me,
still want to find a single explanation of a single universe
It was this ambition to explain a single universe
which kept hopes for string theory alive,
even when it seemed to be going nowhere.
In the last several years,
we've been in the wilderness,
the mathematics has proven too difficult to solve superstring theory,
the theory is smarter than we are.
The creative engine behind superstring theory is Ed Witten, at Princeton.
In fact,
Scientific American once said that Ed Witten is,
guote, the smartest man on earth,
unguote, and if anyone is smart enough to solve superstring theory,
it's probably going to be Ed Witten.
It seemed pretty clear that if there was a chance to go way
beyond familiar understanding of physics,
string theory was the most ambitious prospect.
It also was clear then, as it is now,
that it was a very long-term proposition.
Witten turned away from more concrete aspects of physics,
to tackle the highly theoretical mathematics of string theory.
I wasn't originally interested in maths,
I was interested in doing physics,
and I remember very well having some reticence for guite some time
about making the one hundred per cent commitment,
of really deciding that was going to be my life.
However bizarre its claims, string theory,
like all scientific ideas,
has to survive a basic test: Can it describe the world we know?
String theory, as it had developed by the mid-eighties,
was characterised by the fact that there were five theories we knew about,
and that raised the rather curious guestion
that was always a little bit embarrassing.
If one of those theories describes our universe,
then who lives in other four universes?
We've come to understand that those five theories
we've been studying are all limiting cases of one big picture.
To make an analogy with the blind man and the elephants,
there is the guy who discovered the trunk
and there's the guy who discovered the tail,
and there's the guy who discovered the ear,
and in the past we thought there
were five different things,
now we know there is one elephant,
we still don't understand that elephant too well.
Witten remains convinced that string theory can make sense.
But it's lonely work.
He lives in a strange, abstract world,
where many dimensions exist rather than the four we experience on earth.
Even other physicists, used to working in abstract spaces,
find it difficult to share his convictions.
A lot of people, even professional physicists,
in my opinion,
don't fully grasp the scope and richness of the structure involved.
People may tend to be too impatient for guick results in. Some cases.
I think that there are a lot of reasons to think
that a structure which is so rich
and so physical and which has been the source,
the continued source of so many beautiful discoveries
must be on the right track
Like Einstein before him,
Witten's instincts drive him on.
But a solution is painfully elusive.
When you are doing a calculation,
it's usually on some very specific detail,
it's a tiny, tiny part of the big picture,
and you're hoping that that piece with shed light on the big picture,
sometimes it does but usually it doesn't.
Oftentimes you come home at the end of the day
and you know exactly the amount you knew at the beginning of the day.
But sometimes, you know a little bit more.
I think that this investigation is the richest thing
that physicists can tackle, and how far we'll get in our lifetimes,
there's no way to know,
and we might get the answers we dream of getting,
we might fall a little short,
But I think we can accomplish more in the future,
and getting as far as we can is the best we can do.
Twenty years ago, I said there was a fifty-fifty chance
we would have a complete picture of the universe in the next twenty years.
That is still my estimate today,
but the twenty years starts now.
It's very hard to build a cons-,
a fully consistent guantum theory of gravity.
The string. Theorists think they have one,
they may well not be right,
they haven't yet pushed their theory far enough
so you can compare the conseguences of string theory to experiment,
and that's what you ultimately need
But perhaps, for the first time,
an experimental group could be closer to hand.
Neil Turok is getting ready to journey into the unknown.
Like any explorer, he needs to know where he's going.
But our current map of the early universe isn't good enough.
Imagine you were trying to navigate across a continent,
and you had a map which only showed features
greater than a hundred miles across,
er, it wouldn't be much use in finding your way,
er, along a particular route,
but if you had a map that has a resolution of a mile,
then that becomes much more useful.
In the vast clean rooms of the European Space Agency,
Turok is involved with a project to make the map of all maps,
with a satellite called the Planck Explorer.
What we'll do is look out,
map the whole sky at a very high resolution.
Basically, this is eguivalent to making a map of the earth
where you show all the rivers and the mountains
and the valleys in exguisite detail,
and this map will contain a vast amount of information,
it will give us the best picture we have of the universe
The Planck Explorer will look billions of years back in time,
to when the very first signs of the structure
of the universe are visible.
Turok's map is not the universe as it is, but as it was.
It is a map of the universe of very early times,
we're not sure guite when,
er, the radiation from the big bang was emitted from the,
er, plasma in the early universe,
but, er, when we look out and we see the sky,
we're looking directly at different patches of hot plasma
and there are going to be of slightly different temperature,
and so this will be a map of the temperature variations on the sky.
The hope is that soon we may be able to see the heat
of the early universe in enough detail to answer our guestions
about how it was formed.
If the data is detailed enough,
it could offer observational evidence which may clarify how everything began.
I think, er,
people are usually excessively confident about the theories,
because there has been an absence of data,
and that's allowed people to be confident about the theories,
er, the current theories there are all based on very clever ideas,
er, and very imaginative ideas,
but what's really good about them is
they do give you a well-defined framework within
which you can make predictions.
Turok has turned the maths of theories like superstrings
and inflation into pictures,
which illustrate the subtle temperature variations
that must exist in the early universe
Each theory predicts a different picture.
The Planck Explorer will see if any of them could be right.
We're in the wonderful situation now where,
over the next five or ten years,
the theory is going to be beaten to death,
or theories that we have will be beaten to death in terms of making predictions,
that will all be settled and we'll,
they'll all,
er, say exactly what they expect to find in the sky,
and then this satellite will fly and will map the sky to a very high precision,
and, er, we'll see what happens.
It's a very exciting time to be involved,
it's a unigue opportunity in science where you,
you're told,
within ten years we're going to have the data
that will prove or disprove any theory of how structure formed in the universe,
and you've got ten years,
so we'll see if anyone gets it right.
It could be that in a few years we will have a complete theory
that is confirmed by experiment.
It would be a remarkable achievement,
perhaps the ultimate triumph of science.
But knowing how the universe works is not enough to tell us why it exists.
To find the answer to that guestion would be to know the mind of God.