Is the universe eternal, or did it have a beginning?
Giving his conclusion on the matter, world-renowned theoretical
physicist Stephen Hawking made a 45-minute multimedia presentation
at the Great Hall of the People in Beijing yesterday on the
occasion of the International Conference on String Theory 2006.
String theory traces the development of theories on cosmic
origin.
Through his electronic speech synthesizer, Hawking described how
the general theory of relativity and the discovery of the expansion
of the universe provoked conceptual changes, which meant that the
idea of an ever-existing, ever-lasting universe was no longer
tenable.
The 64-year-old scientist and author of the global best-seller
A Brief History of Time uses a wheelchair and communicates
with the help of a computer because he suffers from the
neurological disorder, amyotrophic lateral sclerosis or ALS.
One of the best-known theoretical physicists of his generation,
Hawking has done groundbreaking research on black holes and the
origins of the universe, proposing that space and time have no
beginning and no end.
The image Hawking drew of this process was that of bubbles
appearing and bursting, corresponding to mini universes that expand
and collapse. Only those that grew to a certain size would be safe
from collapse and would continue to expand at an ever increasing
rate.
According to the theorem he and Professor Roger Penrose jointly
developed in 1970, general relativity predicated that the universe
and time itself would begin with the big bang and that time would
come to an end in black holes.
"One can get rid of the problem of time having a beginning in a
similar way in which we got rid of the edge of the world," Hawking
said.
Likening the beginning of the universe to the South Pole, with
degrees of latitude playing the role of time, Hawking explained
that the universe would start as a point at the South Pole.
"As one moves north, the circles of constant latitude,
representing the size of the universe, would expand. To ask what
happened before the beginning of the universe would become a
meaningless question because there is nothing south of the South
Pole," Hawking said.
In this view, the beginning of the universe would be governed by
the laws of science: the creation of the universe would be down to
spontaneous quantum creation.
"Cosmology is a very exciting and active subject. We are getting
close to answering the age-old questions, 'Why are we here?' and
'Where did we come from?'"
(Xinhua News Agency June 20, 2006)