Stephen Hawking

Born	Stephen William Hawking
	8 January 1942 (age 72)
	Oxford, England
Residence	United Kingdom
Fields	General relativity
	Quantum gravity
Notable awards	Adams Prize (1966)
	FRS (1974)
	Eddington Medal (1975)
	Maxwell Medal and Prize (1976)
	Heine man Prize (1976)
	Hughes Medal (1976)
	Albert Einstein Award (1978)
	CBE (1982)
	RAS Gold Medal (1985)
	Dirac Medal (1987)
	Wolf Prize (1988)
	CH (1989)
	Prince of Asturias Award (1989)
	Andrew Gemant Award (1998)
	Naylor Prize and Lectureship (1999)
	Lilienfeld Prize (1999)
	Albert Medal (Royal Society of Arts) (1999)
	Copley Medal (2006)
	Presidential Medal of Freedom (2009)
	Fundamental Physics Prize (2012)

An English theoretical physicist, cosmologist, author and Director of Research at the Centre for Theoretical Cosmology within the University of Cambridge. Among his significant scientific works have been a collaboration with Roger Penrose on gravitational singularity theorems in the framework of general relativity, and the theoretical prediction that black holes emit radiation, often called Hawking radiation. Hawking was the first to set forth a cosmology explained by a union of the general theory of relativity and quantum mechanics. He is a vocal supporter of the many-worlds interpretation of quantum mechanics.

 Hawking is an Honorary Fellow of the Royal Society of Arts, a lifetime member of the Pontifical Academy of Sciences, and a recipient of the Presidential Medal of Freedom, the highest civilian award in the United States. Hawking was theLucasian Professor of Mathematics at the University of Cambridge between 1979 and 2009.

Hawking has achieved success with works of popular science in which he discusses his own theories and cosmology in general; his A Brief History of Time stayed on the British Sunday Times best-sellers list for a record-breaking 237 weeks.

Hawking has a motor neuron disease related to amyotrophic lateral sclerosis (ALS), a condition that has progressed over the years. He is almost entirely paralysed and communicates through a speech-generating device. He married twice and has three children.

Hawking taking a zero-gravity flight in a "Vomit Comet"

 1970 Singularities in gravitational collapse

Physicists working on Einstein's theory of gravity noticed that it allowed for singularities – points where spacetime appeared to be infinitely curved. But it was unclear whether singularities were real or not. Roger Penrose at Birkbeck College in London proved that singularities would indeed form in black holes. Later, Penrose and Hawking applied the same idea to the whole universe and showed that Einstein's theory predicted a singularity in our distant past. It was the big bang.

1971-72 Black hole mechanics

Black holes have their own set of laws that mirror the more familiar laws of thermodynamics. Hawking came up with the second law, which states that the total surface area of a black hole will never get smaller, at least so far as classical (as opposed to quantum) physics is concerned. Also known as the Hawking area theorem, it created a puzzle for physicists. The law implied that black holes were hot, a contradiction of classical physics that said black holes could not radiate heat. In separate work, Hawking worked on the "no hair" theorem of black holes, which states that black holes can be characterized by three numbers – their mass, angular momentum and charge. The hair in question is other information that vanishes when it falls into the black hole.

1974-75 How black holes can vanish

Nothing can escape a black hole, or so physicists once thought. Hawking drew on quantum theory to show that black holes should emit heat and eventually vanish. The process is slow for normal black holes. It would take longer than the age of the universe for a black hole with the same mass as our sun to evaporate. But smaller black holes evaporate faster, and near the end of their lives release heat at a spectacular rate. In the last tenth of a second, a black hole could explode with the energy of a million one megaton hydrogen bombs.

Stephen Hawking being presented by his daughter Lucy Hawking at the lecture he gave for NASA's 50th anniversary

1982 How galaxies might arise

A popular theory in cosmology holds that the fledgling universe went through a period of rapid inflation soon after the big bang. Hawking was one of the first to show how quantum fluctuations – minuscule variations in the distribution of matter – during inflation might give rise to the spread of galaxies in the universe. What started as a tiny difference grew into the cosmic structure we see, as gravity made matter clump together. Recent maps of the heavens that pick up the faint afterglow of the big bang reveal the kinds of variations Hawking worked with.

1983 Wave function of the universe

Hawking has spent much of his time trying to develop a quantum theory of gravity. He started out applying his idea of Euclidean quantum gravity to black holes, but in 1983 teamed up with Jim Hartle at Chicago University. Together they proposed a "wave function of the universe" that, in theory, could be used to calculate the properties of the universe we see around us.

Videos 

Books

 .......................created by Gitanjalee Bhuse-Ghodake