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- It is going to take a little longer than expected to
get a so-called "theory of everything'' to explain the Universe, says
Stephen Hawking.
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- The world famous physicist is attending a conference
on string theory, the idea that on a fundamental level all matter and indeed
space and time itself is made of tiny loops of energy.
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- In the 1980s, when string theory was fairly new, he said
there was a 50-50 chance the theory would be proven in 20 years. Now he
is not so sure.
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- "Although we have made great progress in the last
20 years, we don't seem much nearer to our goal,'' he said. He now believes
it could take another 20 years.
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- Some scientists hope that string theory could unite the
two main theories of physics: Einstein's theory of general relativity which
deals with the large scale structure of space and time, and quantum theory
which deals with the fundamental nature of matter and energy.
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- Mutually incompatible
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- The problem is that while both theories are spectacularly
good at explaining the Universe within their own terms, they are mutually
incompatible. They cannot both be right.
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- In fact, probably neither them is. They may be part of
a larger more profound theory. String theory is one candidate, by no means
the only one, for such a "theory of everything."
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- The weeklong annual conference he is attending is called
Strings '99. It is being held in Germany for the first time. It takes place
close to Albert Einstein's summer home, where he spent his last years in
Germany pondering a unifying theory for physics.
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- After he left Germany, he continued work on a so-called
unified theory at Princeton University, but never found a solution. According
to Hawking, however, a unified theory may not have a solution that works
all the time.
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- "There may be no theory that can be applied in different
situations," he said, speaking through a computer attached to his
wheelchair," just as there is no map that covers the entire world.
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- "We don't understand the origin of the Universe
or why we are here,'' he added. "A complete unified theory might not
bring much material benefit, but it would answer that age-old question.''
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