Posted on 24-2-2004
Ultimate
equation is pie in the sky, says Hawking
Ian Sample, science correspondent
For many scientists, it was the ultimate quest: the hunt for
a mathematical equation that described, in principle at least,
everything in the universe.
But it seems a "theory of everything" may forever
be beyond our grasp. Stephen Hawking, the Cambridge University
physicist who suggested in A Brief History of Time that scientists
were on the verge of discovering such a theory, has changed
his mind.
We may have to make do with never understanding the universe
completely, he says.
A theory of everything would be the ultimate in scientific
determinism. If we knew the position and velocity of every single
particle in the universe, and understood the laws of physics
that governed them, we could - given enough computing power
- work out the state of the universe and everything in it, at
any time we chose. Or so the argument goes.
So powerful would the equation be, that to know it would be
to know the mind of God, Professor Hawking famously remarked.
His decision to abandon the hunt for a theory of everything
is outlined in a paper posted online.
In Gödel and the End of Physics, Prof Hawking describes
how ideas put forward by the late mathematician Kurt Gödel
all but rule out a theory of everything.
Gödel developed a series of mathematical paradoxes that
could not be proved. If there were such mathematical conundrums,
then there must also be physical problems, such as understanding
the universe, that will also be beyond us, Prof Hawking argues.
He admits his change of heart will disappoint many.
"Most people have implicitly assumed that there is an
ultimate theory that we will eventually discover. Indeed, I
myself have suggested we might find it quite soon," he
writes.
But he remains upbeat. Knowing some things will forever remain
unknown will keep scientists motivated. "I'm now glad that
our search for understanding will never come to an end, and
that we will always have the challenge of new discovery. Without
it, we would stagnate."
Sir Martin Rees, the astronomer royal, said a "theory
of everything" had long been considered unlikely. "In
some sense, there must be such a theory, but its nature and
what it will imply is very controversial," he added.
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