- A group of astronomers and cosmologists has warned that
the laws thought to govern the universe, including Albert Einstein's theory
of relativity, must be rewritten.
- The group, which includes Professor Stephen Hawking and
Sir Martin Rees, the astronomer royal, say such laws may only work for
our universe but not in others that are now also thought to exist.
- "It is becoming increasingly likely that the rules
we had thought were fundamental through time and space are actually just
bylaws for our bit of it," said Rees, whose new book, Our Cosmic Habitat,
is published next month. "Creation is emerging as even stranger than
- Among the ideas facing revision is Einstein's belief
that the speed of light must always be the same - 186,000 miles a second
in a vacuum. There is growing evidence that light moved much faster during
the early stages of our universe.
- Rees, Hawking and others are so concerned at the impact
of such ideas that they recently organised a private conference in Cambridge
for more than 30 leading cosmologists.
- Cosmology - the study of the origins and future of our
universe - became popular in the early 20th century for physicists who
wanted to think the unthinkable about creation.
- Einstein's theory of relativity, which describes how
gravity controls the behaviour of our universe, was one of cosmology's
greatest triumphs. But Einstein said there was an even deeper issue, which
he described as whether God had any choice. In other words, could the laws
that governed the way our universe formed after the big bang have worked
any differently? He concluded that they could not.
- In the past 40 years, however, the increasing power of
astronomical instruments has turned cosmology from a theoretical science
into a practical one and forced scientists to re-examine Einstein's conclusions.
Among the most striking claims is that our universe only exists because
of a fine balance between several crucial factors.
- One is the rate at which nuclear fusion releases energy
in stars such as the sun by squashing hydrogen atoms into helium and then
other elements. Astronomers have found that exactly 0.7% of the mass of
the hydrogen is converted into starlight and that if this figure had been
just a fraction different then carbon and other elements essential to life
could never have formed.
- Another puzzle is the so-called "smoothness"
of our universe, by which astronomers mean the distribution of matter and
radiation. In theory, the big bang could have produced a universe where
all the matter clumped together into a few black holes, or another in which
it was spread out evenly, forming nothing but a thin vapour. "It
could be that the laws that govern our universe are unchangeable but it
is a remarkable coincidence that these laws are also exactly what is needed
to produce life," said Rees. "It seems too good to be true."
- What he, Hawking and others such as Neil Turok, professor
of maths and physics at Cambridge, are now looking at is the idea that
our universe is just one of an infinite number of universes, with different
laws of nature operating in each.
- Some universes would have all their matter clumped together
into a few huge black holes while others would be nothing more than a thin
uniform freezing gas.
- However, Hawking and his colleagues increasingly disagree
over how this "multiverse" could work. At the conference Hawking
dismissed the idea of a series of big bangs on the grounds that it extended
into the infinite past and so could never have a beginning.