Science Facts Forum: The Legend of Physics

The Legend of Physics: Stephen William Hawking

INTRODUCTION

He (8 January 1942-14 March 2018) was an English Theoretical Physicist, cosmologist, and author, who was director of research at the Centre for Theoretical cosmology at the University of Cambridge at the time of his death. He was the Lucasian Professor of Mathematics at the University of Cambridge between 1979 and 2009.

His scientific works included a collaboration with Roger Penrose on gravitational singularity theorems in the frame work of general relativity and the theoretical prediction that black holes emit the radiation, often called Hawking Radiation. Hawking was the first to setout a theory of cosmology explained by a union of the general theory of relativity and quantum mechanics. He was the vigorous supporter of the many worlds interpretation of quantum mechanics.

Hawking achieved commercial success with several works of popular science in which he discuss his own theory and cosmology in general. His book A Brief History Of Time appeared on the British Sunday Times Best seller list for a record breaking 237 weeks. Hawking was the Fellow of the Royal Society(FRS), A life time member of the Pontifical Academy of Sciences and a recipient of the presidential medal of freedom, the highest civilian awarded in the United States. In 2002, Hawking was ranked a number 25 in the BBC’s poll of the 100 Greatest Britons. Hawking had a rare early –onset slow –Progressing form of motor neurone disease(also known as Amyotrophic lateral sclerosis ‘’ALS’’ or Lou Gehrig’s disease) that gradually paralyzed him over the decades. Even after the loss of his speech, he was still able to communicate through a speech generating device, initially through use of a hand held switch, and eventually by using single cheek muscle. He died on 14 March 2018 at the age of 76.

Some important discoveries of Stephen Hawking:

1. Singularity

Einstein's theory also tells about singularity,that is where the space time appeared to be infinite curve but at that time it was unclear that singularity was real or not, later Roger Penrose proved that singularity would indeed form in black hole later, Stephen hawking did path breaking work on singularities and applied it for whole universe and told that gravitational force produces singularities. He also told that Einstein's theory produced a singularity that is the big bang and hawking proved it mathematically.

2. Cosmic Inflation theory 1982

This theory was introduced by Alan goth in 1980. That is, in physical cosmology cosmic inflation is a theory in which the universe expands exponentially soon after the big bang. Further Hawking was one of the first who calculated quantum fluctuations which means the small variation in the distribution of matter and shows that, during inflation, it might give rise to the spread of galaxies in the universe.

3. Model on the wave function of the universe 1983

Stephen hawking was interested in establishing a quantum theory of gravity, but with James hartle, he published a model, the hartle - hawking state in 1983.

This theory states that, time did not exist before the big bang explosion and hence the concept of beginning of the universe is meaningless. The universe does not have any initial boundaries in time or space.

4. Top-down theory on cosmology 2006

Along with Thomas hertog, he proposed a theory “top-down cosmology" in 2006. It proposed that the universe had not one unique initial state but consisted of a superposition of many possible initial conditions. several other books were also published like “the universe in a nutshell”, “God created the integers: Mathematical breakthrough that changed history" in 2005 etc.

Law of Black Hole Mechanics

Stephen hawking discovered the law of mechanics in 1971 – 1972. His first law states that the total surface area of the black hole will never get smaller. It is also known as the hawking area theorem. Another law states that, Black hole were hot. But it is a contradiction of classical physics which states that black hole doesn’t radiate heat. Another law is no gain theorem of black holes, which states that black hole can be characterized by three numbers; their mass, angular momentum and charge.

One more law is, black holes emit the radiation, which may continue till they exhaust their energy and evaporates. Which is also called as hawking radiation. In 1971 he won the prestigious gravity research foundation award for his essay black hole.

Personal life

Hawking had a rare early onset slow progressing form of motor neuron disease or ALS, that gradually paralyzed him over the decades. The diagnosis of ALS came when he was at 21 in 1963. At the time doctors gave him a life expectancy of two years. In 1960’s his physical abilities declined, he began to use a crutch and as he lost the ability to write he developed compensatory visual methods including seeing equations in terms of geometry and at last he lost his voice and control over his body and he stick into a wheel chair at his younger age only, but his brain was still awake and active and it created magic all over the world. The entire world was shocked because of the discoveries and achievements of a parlayed man, and he became the pole star of physics.

When hawking was a graduate student he met jane wild before his diagnosis of ALS, and the couple became engaged in 1964 and they got 3 children, Robert, Lucy and timothy. But in 1980 they got separated after that he married Mason and this marriage also broke down soon.

Awards