New Delhi: Stephen Hawking, the British physicist and black-hole theorist who brought science to a mass audience with the best-selling book ‘A Brief History of Time’, has died. He was 76.
Hawking, who suffered from amyotrophic lateral sclerosis (also known as Lou Gehrig’s disease), was confined to an electric wheelchair for much of his adult life. Diagnosed at age 21, he was one of the world’s longest survivors of ALS.
A Cambridge University professor, Hawking redefined cosmology by proposing that black holes emit radiation and later evaporate. He also showed that the universe had a beginning by describing how Albert Einstein’s theory of general relativity eventually breaks down when time and space are traced back to the Big Bang about 13.7 billion years ago.
‘A Brief History of Time’, first published in 1988, earned its author worldwide acclaim, selling at least 10 million copies in 40 languages and staying on the best-seller list of the UK’s Sunday Times newspaper for a record 237 weeks.
Often referred to as “one of the most unread books of all time” for the hard-to-grasp concepts, it included only one equation: E = mc2 or the equivalence of mass and energy, deduced by Einstein from his theory of special relativity. The book outlined the basics of cosmology for the general reader.
Hawking’s fame increased as his health worsened. After his degenerative muscle disorder was diagnosed, he defied medical opinion by living five decades longer than expected. He communicated his ideas through an American-accented speech synthesizer after a life-saving tracheotomy in 1985 took away his ability to speak. To the layman, the robot-like voice only seemed to give his words added authority.
Hawking applied quantum theory – governing the subatomic world – to black holes, which he claimed discharge radiation that causes them to disappear. This process helps explain the notion that black holes have existed at a micro level since the Big Bang, and the smaller they are, the faster they evaporate.
Black holes are formed when a massive star collapses under the weight of its own gravity. Detected by the movement of surrounding matter, they devour everything in their path and may play a role in the birth of galaxies. Physicists say these invisible cosmic vacuums might allow travel through time and space via wormholes, a favourite of science-fiction writers.
With mathematician Roger Penrose, Hawking used Einstein’s theory of relativity to trace the origins of time and space to a single point of zero size and infinite density. Their work gave mathematical expression to the Big Bang theory, proposed by Belgian priest Georges Lemaitre in 1927 and supported two years later by Edwin Hubble’s discovery that the universe is expanding.
Big Bang Theory
With American physicist James Hartle, Hawking later tried to marry relativity with quantum theory by proposing the no-boundary principle, which held that space-time is finite and the laws of physics determined how the universe began in a self-contained system, without the need for a creator or prior cause.
“There was nothing around before the Big, Big Bang,” Hawking told physicist Neil deGrasse Tyson at the “Star Talk” show aired on National Geographic Channel earlier this month.
According to Hawking, the laws of physics and time cease to function inside that tiny particle of heat and energy. The ordinary real time as we know now shrinks infinitely as the universe becomes ever smaller but never reaches a definable starting point.
“It was always reaching closer to nothing but didn’t become nothing,” said Hawking.
He drew an analogy between the distorted time with Ancient Greek philosopher Euclid’s theory of space-time, a closed surface without end.
“One can regard imaginary and real time beginning at the South Pole. There is nothing south of the South Pole… There was never a Big Bang that produced something from nothing. It just seemed that way from mankind’s perspective,” Hawking explained.
