Later Years

His next major contribution would be the Penrose–Hawking theorems on gravitational singularities. Most of these were published during the early 1970s. Simply put, in Einstein’s theory of relativity points arise where spacetime seems to be infinitely curved, but it was unknown whether these points were actually real. Penrose and Hawking proved that these points, or singularities, would form in the gravitational collapse of stars and would exist in black holes. There are two general forces in a star, gravity pulling in, and heat from nuclear fusion pushing out. Once the fuel is spent though and it no longer has the energy released during fusion pushing out it will begin to collapse under its own mass and shrink inward. It is a perpetuating cycle, the more it collapses the denser it becomes. The denser it becomes the more focused the gravitational force becomes pulling it inward. Eventually it hits a point where it will have zero volume but infinite density. In these singularities both time and space cease to exist in any meaningful sense- spacetime wouldn’t just fall into this hole, it’d be so tightly compressed it would disappear. Later the duo would apply the same theories to the entire universe which unequivocally predicted a singularity approximately 13.77 billion years ago, the Big Bang.[5]

Stephen’s most noted scientific achievements were still to follow though. His physical ability had greatly diminished now, and all movements were laborious and slow. It was one night when preparing for the task of getting into bed that Stephen was thinking about what the surface of a black hole must be like. Black holes are said to form when with their given mass collapses to a point where their gravitational pull is so strong that the escape velocity from the surface equals the speed of light; hence where they get their name, since not even light can escape from their grasp. His earlier work with Penrose though had begged the question what happens when a black hole pulls something in since it is seemingly destroying matter and never gaining entropy. He realized though that the surface area of the singularity must remain constant. With this flash of insight he had ruined his preparation for getting into bed, as he was now to spend a sleepless night working on the ramifications of this. It was here that Hawking Radiation was born; that black holes do emit something and are not an endless trap. In another gross over simplification, Hawking radiation is heat.

In 1979 in recognition of his achievements and brilliance he was offered the position of Lucasian Professor of Mathematics at Cambridge University, a seat once held by Sir Isaac Newton. By this point Stephen’s physical state had deteriorated to the point where he was completely confined to his electric wheelchair, he was unable to feed himself, and his ability to speak was almost completely diminished. Practically he could no longer write, but through painstaking effort he inscribed his name in the Lucasian Professor’s register, although this was to be the last time he ever signed his own name. Even so he continued his work, putting great effort into improving his memory and ability to work problem in his head.

The fields of theoretical physics and cosmology are not generally accessible by the average person, the scientific writings on them being indecipherable equations and technical jargon. In a turn that surprised many, Stephen wrote a book hoping to bridge this divide and bring the stars closer to the everyday being. “A Brief History of Time” was published by Bantam Books who expected the book a limited success. With over 200 weeks spent as a London Times best seller and over 10 million copies sold it was more successful than anyone could have predicted.[6] The book helps dispel scientific dogma on such things as the beginning of the universe, black holes, and even unified wave theory.

There is little contention of Stephen Hawking’s genius among the scientific community. His work has been key in helping us understand the cosmos and even going so far as to help demystify it. All of this from a person who growing up never showed the traits commonly thought of in a genius and later left disabled by a rare degenerative disease. His work is crucial to anyone who wants to comprehend the universe around us.