On The Nature and Future of The Universe.
an interview with Lee Smolin
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Metanexus: VIEWS 2001.12.24
2077 words What is the
future of the future? Will it all end in fire or in ice? And what kinds of
events will the penultimate (which is always more interesting and much
trickier than the ultimate!) reveal? These questions (as well as others, of
course!) are addressed to Lee Smolin by Jill
Neimark in today's column titled "A Talk On The Nature and Future of The
Universe". Lee Smolin is a theoretical physicist at the cosmology
think-tank, Perimeter Institute in =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Q: Why do
you think so many physicists are interested in the anthropic
principle of the universe right now-the idea that the universe is ideally
suited to life? A: There's
a good reason and two bad reasons. The good reason is that there are puzzles
about why the universe is the way it is, and why the initial conditions and
choices and laws of physics are very special. And it's good that people are
interested in those puzzles. The anthropic
principle promises to answer those puzzles. The two bad reasons are that,
one: it doesn't really answer those puzzles, it just gives people the
impression they've been answered. Q: How does
it give that false impression? A: There
are different versions, and they do so in different ways. One form assumes
there is an intelligent creator who is displaced or hidden. And the other
version suggests there are an enormous number of universes, maybe infinite,
each created with different initial conditions and different laws and then
somewhere in there by probability there is a universe that looks like ours,
simply because it's possible. That's not an explanation. That's like
explaining biology by saying there is a soup of DNA and every possible
combination of DNA came together and one of them caused a living being.
That's not how biology works, and I don't believe that's how the universe
works either. Q: What's
the other reason you feel the anthropic principle
is flawed? A: People are
still looking for a role for God as creator of universe, and these people
were forced to beat a tactical retreat from God as the direct creator of
human beings because of Q: You're
not a fan of the big bang theory. A: I
personally think the big bang is a crazy idea. What we know is that around 14
billion years ago the universe was much denser and hotter, at least as much
as the center of a star. What happened before that? One possibility is that
the universe simply expanded from a state of infinite density and temperature, however it may also be that the expansion was
the result of some event that took place, and therefore the Big Bang is not
the beginning of time. Q: What
about a bunch of bangs? A: People
have proposed that the Big Bang followed the collapse of a previous universe.
Another idea is that the Big Bang is the result of the collapse of a small
region of another universe, which would have led to the formation of a black
hole. Q: Which
idea do you prefer? A: I
personally think it's very unlikely that the Big Bang was the first moment of
time. I'm very interested in the question, therefore, of what was before the
Big Bang. Q: So there
aren't many universes with different properties? A: I don't
deeply believe that. Q: What do
you deeply believe? A: I deeply
believe that the world is a network of relationships, I deeply believe in
causality, that the past causes the future, the past has already happened and
the future has not, I deeply believe that time and causality are real. I
believe that there is a universe which exists apart from people's perceptions
of it, but I think that a description of that universe from the stance of
outside observer is impossible. Therefore our description has to somehow incorporate
all possible views from all possible observers. Q: How do
we do that? A: There's
been a development in mathematics and theoretical physics which shows us how
to do that. In math it's called topos theory, it's
been applied to physics to give this kind of surrealistic or multi-observer
formulation of quantum theory. A few people who are working on that are Chris
Isham and Jeremy Butterfield and Fotini Markopoulou. Q: What do
you think of recent work in physics showing that certain properties of the universe
may be evolving? A: Evolving
is the wrong word to use. It may be that some things we think of as constants
in physics, like the fine structure constant, might be changing slowly on a
cosmological time scale. The fine structure constant is a ratio formed out of
three things: the electric charge of an electron, Planck's constant, and the
speed of light. Evidence was recently published that was not very strong, but
nonetheless was not trivial, showing that the fine structure might be slowly
changing. Q: What
would that mean for our concept of the universe? A: If its true its fantastically important, because in standard
physical theory these numbers are fixed. The idea that constants of nature
might actually not be constant is an old idea, I
believe Dirac proposed it in 1930s. And this work was preceded by other work
by Joao Maguejo and Andy Albrecht proposing that
the speed of light might have been much larger at very early times of
universe when it was very hot. If that were true, it would account for the
same things that the inflation theory of the universe does. If the
speed of light or other fundamental constants can change a lot during the
extreme conditions at very early times, it might be that there would be small
changes during the present universe. What people have observed is evidence
for such small changes. But it's still the early days. In a few years we'll
know whether it was just an artifact of pushing the experiment to the edge,
or whether it's a real effect. Q: So there
are any constants? Any fixed, platonic properties? A: I'm very
attracted by the idea that there are many fewer than we think, that's not the
same as saying there are none. Q:
Nobel-prize winning physicist Steven Weinberg recently wrote an essay for the
New York Review of Books called "The Future of Science, and the
Universe." In it he talks about how eventually the universe will either
freeze or burn up. Do you agree? Q: Some
cosmologists are interested in what they call the far future of the universe.
I was at conference sponsored by the Templeton organization at the Q: Weinberg
also suggests we'll discover a few fundamental principles, and they will be
fragile-such that, were they to shift only a little, they wouldn't function.
Do you agree with that? A: He means
brittle rather than fragile: if it changes a little, it breaks. I think it
would be nice if there were a few fundamental principles. Some of us are
working on a so-called M theory, where all the versions of string theory are
tied together in a single theory. I think that's a very interesting
conjecture, but it's hard to tell if it's true or not. A great many people
believe in the existence of M theory but very few people are actually working
on its ultimate formulation. Q: Is it
too hard? A: No, but
it requires a change of mindset, from thinking in terms of objects moving
against fixed backgrounds of space and time, to a relational picture of the
universe. Q: The
relational nature of the universe has been your passion for a long time. A: Not just
my passion. The debate about whether space and time are absolute or
relational goes back to the Greeks. Leibniz in particular advocated the
relational view. Leibniz and a follower of Q: But we
don't experience things that way in real life. A: Actually
we do. We notice where something is with respect to something else. Q: That's
true, but we think of things as fixed against a fixed background. A: That's a
habit of thought but it's incorrect. Q: Do you
experience the world relationally? A: I've
been thinking about this stuff for so long it's just natural for me to think
about the world that way. Q: It kind
of shifts your sense of figure and ground, doesn't it? A:
Precisely. And it's a very important shifting not just for physics but many
areas. Darwinian biology is an example of relational thinking, going from an
idea of absolute categories that different biological species represented, to
the idea that species are a result of evolution within a network of
relationships. You see it in social theory, explicitly in the writings of
Harvard legal theorist Roberto Unger. He asks: do you see law as reflecting
absolute principles of justice which are true eternally and which come from
God or human nature or some completely absolute framework? Or do you see law
as the result of an historical process by which different groups with
different points of view interact to define the rules of society? You see it
in art. The old fashioned idea of perspective is that a painting shows things
in relation to some absolute geometry, that things are fixed in space, which
then gave way to abstract art, where what's happening on canvas just has to
do with relationships. And look at the use of space in modern dance as
opposed to 19th century ballet |
