Stephen Hawking (19 page)

One of his oldest and closest friends, the late David Schramm, of the University of Chicago, had a wealth of anecdotes about Stephen's exploits. His favorite recollection from the early seventies concerns the occasion when he first became aware of Stephen's huge potential for enjoying himself. After a conference in New York, Schramm took the Hawkings to a party thrown by a friend in Greenwich Village. Stephen really enjoyed himself, dancing with Jane, spinning his wheelchair around the room, and generally having a great time.

Schramm is also happy to dub his friend an incorrigible flirt and to describe his eyes as tremendously expressive. Women, Schramm claims, were always very interested in Stephen long before his international fame brought him wide attention. Indeed, David Schramm's wife, Judy, was tremendously taken by him when they first met and found his ability to convey his personality by facial expression extremely attractive.

Hawking's interest in dancing has never diminished, and the annual college parties at Caius would not have been the same without his joining in with the other fellows and their partners on the dance floor. Nowadays, in his elevated position as professor and head of the DAMTP, he is still to be seen at Christmas discos organized by the students, dancing the night away. His energy, both at work and at play, has become a legend. As David Schramm said, Stephen is a real party animal.

Between trips abroad and working on black holes with Roger Penrose, Hawking was collaborating with George Ellis on a book eventually to be called
The Large Scale Structure of Spacetime
. The idea for the book had arisen back in 1965, when Hawking was still working toward the completion of his Ph.D. Ellis remembers that the two of them had drawn up a list of future plans, which included “getting married” and “writing a cosmology book together.” Because both of them were busy with other projects and domestic changes, work on the manuscript went very slowly. Ellis spent some time in Hamburg and then in Boston, and the two of them began to see each other less frequently. Through Dennis Sciama, they managed to secure a contract with Cambridge University Press, which was just starting a series of high-level research monographs aimed at professional physicists.

It took six years to finish the manuscript. They divided up the various topics between them and worked independently, meeting when they could to go through each other's contributions and make changes where appropriate. Ellis did all the typing; when Hawking could no longer write, he dictated his material to Ellis, who wrote it up for him. George Ellis was one of Hawking's close associates who could understand his speech, but even he found it difficult at times. He soon discovered that it was much easier to follow what Hawking was saying in discussions about scientific matters, when the conversation consisted largely of familiar technical terms. It was in everyday conversations, which could be about almost anything, that the going got tough.

Because
The Large Scale Structure of Spacetime
took so long to write, events overtook it in a number of areas. In particular, Hawking's own work on black holes (with which Ellis was not directly involved) had progressed faster than they could amend the text. The book dealt purely with classical theories of cosmology, but by the time of its publication in 1973, Hawking had made great strides in the quantum interpretation of black-hole physics, and it was not until it went into a second edition that they were able to update the text. The book caused quite a stir in academic circles and did a great deal for the general prestige of the series. Indeed, Hawking is now considered by Cambridge University Press to be the most distinguished author in its catalog.

The book is incredibly complex, completely unreadable except by experts working in the field of cosmology. Hawking and Ellis had no intention of writing a popular book, and their manuscript fit the requirements perfectly. However, a favorite story in the science department at Cambridge University Press recounts an occasion when an associate of Hawking's ventured his opinion of this first publication. Hawking and Simon Mitton were returning to Cambridge from a meeting at the Royal Astronomical Society in London and happened to be sharing a railway carriage with the radio astronomer John Shakeshaft. As they pulled out of the station, Shakeshaft, who was sitting in the seat opposite Hawking, leaned forward and said, “Well, I got a copy of your book, Steve.”

“Oh, did you enjoy it?” asked Hawking.

“Well,” Shakeshaft replied, “I thought I might make it to page 10, but I only got as far as page 4, and I've given up, I'm afraid!” Despite the complexity of the book, the latest sales
figures show that, since its publication, it has notched up 3,500 copies in hardback and over 20,000 in paperback—one of the best-selling research monographs ever published by Cambridge University Press.

Simon Mitton, who left the Institute of Astronomy in 1977, is now the science director at Cambridge University Press. He has suggested that the book has sold to a large number of undergraduates who bought it because it looks good on their bookshelves but have probably never gotten beyond the second page of tightly packed equations.
The Large Scale Structure of Spacetime
and other, later, technical books of Hawking's showed a definite upturn in their sales curves upon the publication, many years later, of
A Brief History of Time
. After that, the original coauthor's name, “S. W. Hawking,” printed on the jacket was hurriedly changed to “Stephen Hawking,” and the sales figures took another climb.

In the world of black-hole research, work was moving forward at a startling pace, and Hawking was in the vanguard. It was becoming more and more clear to him that the purely classical interpretation of black holes was deficient. In September 1973 he visited Moscow. The head of the Institute for Physical Problems of the USSR Academy of Sciences in Moscow was a fiery little man with a bald head and boundless energy named Yakov Boris Zel'dovich. He and his team had been working on black holes, in particular on the way in which they interacted with light. Hawking returned to Cambridge convinced that they were on to something but were going about things
the wrong way. As he said many years later, “I didn't like the way they derived their result, so I set out to do it properly.”
⁷

What he then decided to attempt was quite revolutionary. As we saw in
Chapter 2
, the two great pillars of twentieth-century physics are quantum mechanics and relativity, but they are at opposite ends of the spectrum as far as physics is concerned. They speak a different language, and nobody had managed to reconcile the two theories. But this was exactly what Hawking had set his sights on. It seemed to be the only way forward if he were to explain the behavior of black holes thrown up by the contradictory ideas of Bekenstein on the one hand and of himself and Penrose on the other.

Sorting out the problem was easier said than done. Working on the equations in his head was difficult enough, but after months of intense work Hawking kept coming up with completely nonsensical results. According to the equations, black holes appeared to be emitting radiation. He, and everyone else at the time, believed this to be impossible. He was still convinced that he was really on to something but took the conscious decision not to discuss the problem with anyone until he had settled the matter one way or another.

Christmas 1973 came and he was still in as much of a mess with the mathematics as he had ever been. He decided to rework the equations. He knew that he had cut corners with some of the derivations and believed that these shortcuts may have held the key to the problem. During the Christmas vacation, he spent lonely weeks running and rerunning the equations through his mind, forcing himself to use ever more complex processes to eradicate the annoying anomalies. Finally, in January 1974 he took the plunge and confided in
Dennis Sciama, who was organizing a conference at the time. To Hawking's surprise, Sciama was very excited by the idea and, with Hawking's permission, set about spreading the word.

A few days later, it was Hawking's thirty-second birthday, and his family arranged a dinner party to celebrate. Soon after the meal was served, the phone rang. It was Roger Penrose calling from London—he had heard the story propagated by Sciama and wanted to know all about it. The discussion went on and on. The food grew cold, and the other guests waited patiently for Hawking to return to the table. Forty-five minutes later, with the meal ruined, he hung up. Penrose was tremendously excited and wanted to discuss it further.

Going against all current ideas about black holes, by the power of mathematical reasoning, Hawking had been forced to the unarguable conclusion that not only did tiny black holes emit radiation, but under certain conditions they could actually explode. By late January, one of his colleagues and friends from postgraduate days, Martin Rees, was convinced that Hawking had made a great discovery. Inspired by his latest discussion with Stephen, he bumped into Dennis Sciama in a corridor at the Institute of Astronomy. “Have you heard?” he said, excitedly. “Stephen's changed everything!”

Sciama dashed off to see Hawking. By the end of the conversation, he too was convinced and persuaded his former student to announce his results at the conference he was organizing in February at the Rutherford-Appleton Laboratory outside Oxford.

Hawking was driven to the laboratory through the icy chill of midwinter Oxfordshire and assisted into the building by one of his research students. Sitting patiently to the side of
the main group, he listened to the other speakers announcing their latest news. As usual, he asked his customary penetrating questions, trying hard to control his great feeling of excitement. He had a hunch, now supported by a number of his respected colleagues and peers, that he was on to something very big. At last he was wheeled to the front of the lecture theater, and his illustrations were projected onto the back wall while he delivered his talk in the almost unintelligible tones to which his colleagues had become accustomed. His final line was delivered. A stunned hush fell over the entire room. You could have heard a pin drop as the audience of scientists tried to absorb the astonishing news. Then the backlash began.

The moderator of the meeting, the English theorist John G. Taylor, jumped up from his seat and proclaimed that what Hawking had said was complete nonsense. Pausing only to drag one of his colleagues from the seat beside him, Taylor stormed from the room and immediately started writing a paper denouncing Hawking's claim. Hawking had expected a reaction, but nothing like this. He simply sat at the podium in shocked silence.

John Taylor's paper was dashed off and sent to the scientific journal
Nature
for publication. The editor of
Nature
sent the draft manuscript to Hawking for his comments before making the decision to publish it. Hawking wrote back to recommend publication. He would not want to stand in the way of anyone rash enough to disclaim his work without having investigated the matter thoroughly.

A month after the meeting outside Oxford, Hawking published in
Nature
his own paper describing the newly discovered phenomena. Within weeks, physicists all over the
world were discussing his work, and it became the hot topic of conversation in every physics laboratory from Sydney to South Carolina. Some physicists went so far as to say that the new findings constituted the most significant development in theoretical physics for years. Dennis Sciama described Hawking's paper as “one of the most beautiful in the history of physics.” This radiation, which he had discovered could be emitted by certain black holes, was from then on known as Hawking Radiation.

However, not everyone was convinced, and it was quite a while before many groups working around the world came to terms with this revolution in black-hole physics. It took until 1976 for Zel'dovich's team in Moscow to accept the new ideas. Zel'dovich ran his institute in an extremely dictatorial manner. What he said went. When he finally gave his endorsement to the theory, his team was compelled to go along with it, just as they had followed him when he had disagreed with it.