>>Stephen Hawking, the British physicist whose body was chained to a wheelchair by the ravages of a degenerative neuromuscular disease, but whose mind soared to the boundaries of the universe and beyond, died Wednesday morning in Cambridge, England. He was 76.
His death came from complications of amyotrophic lateral sclerosis, more commonly known as Lou Gehrig’s disease, from which he had suffered since he was 20.
“He was a great scientist and an extraordinary man whose work and legacy will live on for many years,” his children, Lucy, Robert and Tim, said in a statement obtained by the Associated Press. “His courage and persistence with his brilliance and humor inspired people across the world…. We will miss him forever.”
Hawking, whose contributions to theoretical physics are frequently compared to those of Albert Einstein, was the Lucasian professor of mathematics at Cambridge University, occupying the same seat once held by Sir Isaac Newton. From that venerated position, he changed the way the universe is viewed by physicists and laymen alike — the former through his seminal theories about the nature of black holes and the origin of the universe, the latter with a bestselling book, “A Brief History of Time,” which fulfilled his ambition by appearing on the shelves of airport newsstands throughout the world.>>
He was an extraordinary figure, not least because of his half century-long struggle with a deadly, debilitating disease.
Wikipedia highlights some key career points, starting with his succession to the Cambridge chair once held by Newton:
>>In the late 1970s, Hawking was elected Lucasian Professor of Mathematics at the University of Cambridge. His inaugural lecture as Lucasian Professor of Mathematics was titled: “Is the End in Sight for Theoretical Physics” and proposed N=8 Supergravity as the leading theory to solve many of the outstanding problems physicists were studying. His promotion coincided with a health crisis which led to his accepting, albeit reluctantly, some nursing services at home. At the same time, he was also making a transition in his approach to physics, becoming more intuitive and speculative rather than insisting on mathematical proofs. “I would rather be right than rigorous”, he told Kip Thorne. In 1981, he proposed that information in a black hole is irretrievably lost when a black hole evaporates. This information paradox violates the fundamental tenet of quantum mechanics, and led to years of debate, including “the Black Hole War” with Leonard Susskind and Gerard ‘t Hooft.
Cosmological inflation – a theory proposing that following the Big Bang, the universe initially expanded incredibly rapidly before settling down to a slower expansion – was proposed by Alan Guth and also developed by Andrei Linde. Following a conference in Moscow in October 1981, Hawking and Gary Gibbons organised a three-week Nuffield Workshop in the summer of 1982 on “The Very Early Universe” at Cambridge University, which focused mainly on inflation theory. Hawking also began a new line of quantum theory research into the origin of the universe. In 1981 at a Vatican conference, he presented work suggesting that there might be no boundary – or beginning or ending – to the universe. He subsequently developed the research in collaboration with Jim Hartle, and in 1983 they published a model, known as the Hartle–Hawking state. It proposed that prior to the Planck epoch, the universe had no boundary in space-time; before the Big Bang, time did not exist and the concept of the beginning of the universe is meaningless. The initial singularity of the classical Big Bang models was replaced with a region akin to the North Pole. One cannot travel north of the North Pole, but there is no boundary there – it is simply the point where all north-running lines meet and end. Initially, the no-boundary proposal predicted a closed universe, which had implications about the existence of God. As Hawking explained, “If the universe has no boundaries but is self-contained… then God would not have had any freedom to choose how the universe began.”
Hawking did not rule out the existence of a Creator, asking in A Brief History of Time “Is the unified theory so compelling that it brings about its own existence?” In his early work, Hawking spoke of God in a metaphorical sense. In A Brief History of Time he wrote: “If we discover a complete theory, it would be the ultimate triumph of human reason – for then we should know the mind of God.” In the same book he suggested that the existence of God was not necessary to explain the origin of the universe. Later discussions with Neil Turok led to the realisation that the existence of God was also compatible with an open universe.
Further work by Hawking in the area of arrows of time led to the 1985 publication of a paper theorising that if the no-boundary proposition were correct, then when the universe stopped expanding and eventually collapsed, time would run backwards. A paper by Don Page and independent calculations by Raymond Laflamme led Hawking to withdraw this concept. . . . . Along with Thomas Hertog at CERN and Jim Hartle, from 2006 on Hawking developed a theory of “top-down cosmology”, which says that the universe had not one unique initial state but many different ones, and therefore that it is inappropriate to formulate a theory that predicts the universe’s current configuration from one particular initial state. Top-down cosmology posits that the present “selects” the past from a superposition of many possible histories. In doing so, the theory suggests a possible resolution of the fine-tuning question. >>
It has been said that Hawking was the most famous physicist not to hold a Nobel Prize. END