Unlike Newton and Einstein, who
contributed to a wide range of fields, Stephen Hawking focused on
cosmology where he made significant contributions ever since his
graduate student days in Cambridge University, U.K.
If one had to name only three physicists
who touch the lives of people beyond the limits of labs and
universities, the answer, without any hesitation, could be Newton,
Einstein and Stephen Hawking.
Newton’s laws of motion, especially the
third one, inspire millions to query and to quip, and Einstein has, in
the 20th and 21st centuries, become the epitome of what a scientist
should be like. In the case of Hawking, his life and works touch
millions not just because of his bestselling book, The Brief History of
Time, but also because, unlike Newton and Einstein who contributed to a
wide range of fields, he focused on cosmology, despite his extreme
physical disability.
Besides his contribution to cosmology
since his graduate student days in Cambridge University, U.K., Hawking’s
life was a major inspiration to people in general.
Onset of an incurable disease
In 1962, one day he had difficulty tying
his shoelaces. It was no small problem and he was diagnosed with
Amyotrophic Lateral Sclerosis (ALS), a motor neuron disease. The
incurable disease could be fatal and he was given two years to live by
doctors. He was then just over 22 years. He did go into a depression,
doubly so because his dream of working with the famous cosmologist Fred
Hoyle in Cambridge did not materialise. It was then that his
relationship with Jane Wilde, whom he later married, deepened and helped
pull him out. He went on to do his PhD under the supervision of Dennis
Sciama in Cambridge University’s physics department.
Ironically, Hawking ended up refuting
Hoyle’s ideas in his PhD thesis itself. The dominant paradigm of the
universe at the time Hawking began his PhD was the Steady State theory
of the universe, of which Hoyle was a major proponent.
In papers published in the late 1940s,
Hoyle argued that the universe had no beginning. Despite evidence that
galaxies are moving away from each other, he argued that more matter was
being created that kept the overall density a constant. This theory was
a serious contender to the Big Bang theory. In fact, Hoyle was the one
who in 1950s coined the term, ‘Big Bang’, though derisively.
Influenced by work of Roger Penrose
When Hawking came into the picture, he was
influenced by the work of Roger Penrose, who was an applied
mathematician working on singularity theory. Sciama drew Penrose’s
attention towards stars and black holes and the latter came up with the
theory that if a star collapses beyond a point, it would be unable to
stop this. With general theory of relativity, it could only reach an
infinite density at the end of the process, or a singularity.
Hawking got interested in this work and
applied it to the whole universe. He came up with the result that if
general relativity was correct, there must have been a point far back
where there must have been such a singularity. This was his contribution
to the Big Bang cosmology and for which he got his PhD.
This work, early in his career, was just one step but a big one in making him an internationally known scientist.
Among many interesting books on Hawking is
''Stephen Hawking: A Graphic Guide'' by J.P. McEvoy and Oscar Zarate,
which helped the author in writing this article.
Source : http://www.thehindu.com/
