[Steven Weinberg] and in fact, not in half a dozen different ways, but
the solutions to string theory are incredibly numerous.
And in fact the estimate that people usually quote,
although it's, it's highly approximate,
is something like 10 to the 500th solutions of string theory.
And these solutions fill out what string theorists call a landscape.
And each one of them may represent the possible
kind of big bang. Again, this is very speculative
because we don't understand string theory yet
at the deep level that we need to understand it.
But this has already upset some religious leaders.
Cardinal Schönborn, the Cardinal, Archbishop...yeah [Richard Dawkins] I know his name yes (laughing).
[Weinberg] Well you've had problems with him with regards to evolution.
He wrote an op-ed article in the Times a few years ago
in which he, he attacked the old Darwinian synthesis,
-is that the right word? -Yeah.
[Weinberg] Yeah. He attacked the idea of evolution without design
but he also attacked the multiverse idea.
[Dawkins] Yes.
And, it did my heart good to see that because , you know, you,
evolutionary biologists get all the fun of being attacked
by religious zealots and here Cardinal Schönborn at least
knew enough about cosmology to realize
we were worth attacking.
[Dawkins] I'm glad you enjoy it. I must say I don't mind either.
[Weinberg] No. Isn't it better than being ignored?
[Dawkins] Yes. There are teachers of biology in this country
who tell me that they are intimidated. That they don't dare teach
these contentious subjects. I find it hard to understand, because
I should have thought it would be more interesting
to teach something controversial.
But they are frightened of being,
I don't know,
attacked by parents or by maybe the children themselves sometimes.
[Weinberg] Well, yes. I mean the uh, I think...
There are school boards that are very backward.
I testified in front of the Texas State Board of Education.
[Dawkins] Which is particularly influential because of
-text books for some reason. -Yes, that's right.
[Weinberg] At that point, they were honestly confused.
They really thought that intelligent design was
an alternate scientific theory, and why not
present both scientific theories?
They were not anti-science.
They...
[Dawkins] They thought it was science. [Weinberg] They thought it was science and they were
I think, their mind was changed by scientists coming
before them and telling them no its not science.
Its jiggery pokery.
[Dawkins] I mean the myth of being assiduously promulgated
that this was science and they were taken in by it.
[Weinberg] I mean there are people who are...
much more difficult to deal with
than I found the Texas Board of Education.
And I think, and we won that argument.
Now its coming up again in Texas. I think this is beginning
-to be a problem in Europe. -Yes.
[Weinberg] and I understand its very much a problem
in the Islamic world. There is a strong prejudice
-against teaching the theory of evolution. -Yes that's true.
[Weinberg] In fact perhaps in teaching basic science at all.
The Islamic world took a turn away from science
some time in the 12th or 13th century
which was quite tragic.
[Dawkins] Given their good role in preserving Greek science before.
[Weinberg] There's a lovely line in Philip Hitti's
book about the Arabs. He's talking about
the great period of the House of Wisdom
in Baghdad at the time of
Caliph Harun Al-Rashid and Al Mamun. And he said
"While Al-Rashid and Al Mamun were studying
Greek and Persian philosophy,
Charlemagne and his lords were dabbling
in the art of writing their names."
[Dawkins] (laughing) Right, very good. Coming back to the alleged fine tuning
of the universe, I was interested in one of
the things you said, well, many things, but
I've always tried to explain it as an amateur,
because I'm not a physicist, having accepted the word
of physicists that there is an element of fine tuning
and I've tried to lay out three possible explanations.
One would be God, which I have said, isn't an explanation at all.
One would be the multiverse and then anthropically
with hind sight, say we have to be sitting in one of the universes they could give us.
The third one, which I have attributed to you,
-possibly wrongly. -Oh no! Hope not.
[Dawkins] Would be what I call the macho physicists
who say, well, it's just that we don't understand
why these things are the way they are. One day we will,
when we have a theory of everything it will be understood.
But it sounds from our conversation as though
I misrepresented you there.
[Weinberg] Well, I don't know. I really am not impressed with the amount
of fine tuning there is, with the exception of this one
the dark energy. That, you can say qualitatively,
the amount of dark energy now is comparable to
the amount of energy in matter now.
Its a few times larger but its not very different.
Maybe there will be an explanation for that.
A fundamental explanation.
People have aimed at that sort of thing,
Stephen Hawking, for instance, has.
So I think its fair to say we don't know.
If you discovered a really impressive fine tuning
that, if you changed some otherwise arbitrary parameter,
numerical quantity, by 1% in either direction, life would
become impossible, and that
was just the free constant in your theory,
it could have any value, then I think you
would really be left with only the two other explanations.
Either a benevolent designer or a multiverse.
[Dawkins] But the benevolent designer, we know can't work
because it begs the question that you've raised.
So that leaves us with the multiverse, doesn't it?
[Weinberg] Well it doesn't solve the problem but it
opens up the realm of possible speculation
in a way that I can't even imagine thinking.
But it changes the nature of the game.
But the multiverse would be really an explanation then.
[Dawkins] A very satisfying, I've heard it said that physicists
somehow think it's cheating, but I think it's
rather elegant, rather beautiful.
[Weinberg] Well we've had to live with this before,
you know. There was a time when it was thought
that the distances of the planets from the sun
were dictated by geometrical principles.
Kepler had a theory like that although it was only
the ratios of the distances.
And it was somewhat of a disappointment to learn
with Newton's theory, that we were never
going to have a fundamental theory of the
distances of planets from the stars.
I mean, each planet is the distance it is because
of a historical accident that can't...
When will we ever to explain precisely why
the earth is 93 million miles from the sun?
No. Clearly, we're not going to be able to do that.
The only explanation is a rather fuzzy anthropic one,
which allows it to be 92 or 94 million miles from the sun.
The difference between that and the multiverse is
of course we can see that there are lots of planets.
We have only discovered a few dozen planets in this universe
but our theories tell us that there are vast numbers
because a large fraction of stars seem to have planets.
So the existence of the other planets is no longer a speculation.
Well the existence of the other big bangs is a
pure speculation right now. But it may not always be.
[Dawkins] But it, it's not the case that the existence of the
other big bangs we postulate only for anthropic reasons.
[Weinberg] No. That's right. [Dawkins]You have other reasons.
[Weinberg] In fact Cardinal Schönborn, in his op-ed article,
said precisely that the multiverse idea was invented in order
to avoid the appearance of design in the universe.
And that simply is not true. It's historically not true.
[Dawkins] Now going back to the planets, which is a much easier case, of course,
I think you can turn this argument, quite interestingly,
on its head, and point out that since there are obviously
probably billions and billions of billions of planets,
if, which is perfectly possible, only one of them has life,
because we know nothing else than that,
then we would have to say that our theories of
the origin of life, in our theories of the origin of life,
we are looking for a chemical event which has to be
quite staggeringly improbable.
Because otherwise we would expect the universe
to be teeming with life.
Well you are the biologist, you would know better than I do.
How improbable do you think it is?
That's a quite separate question. And it's an interesting question.
But what I'm saying is that the statistical argument allows us
to postulate an event which would be so improbable
that we would ordinarily call it impossible.
Because it only has to happen once.