Stephen Hawking said his disease taught him to do what he still could, and not pity himself. Geoff Robins / Agence France-Presse—Getty Images

Word by painstaking word,Stephen Hawking reveals a bit about his universe

Tempe, Arizona

Like Einstein, he is as famous for his story as for his science.

At the age of 21, the British physicist Stephen Hawking was found to have amyotrophic lateral sclerosis, Lou Gehrig's disease, which is usually fatal within five years. But Dr. Hawking lived on and flourished.

In the 1960s, he used mathematics to explicate the properties of black holes. In 1973, he applied Einstein's general theory of relativity to the principles of quantum mechanics. And he showed that black holes were not completely black but could leak radiation.

Dr. Hawking, in 1988, tried to explain what he knew about the universe to the lay public in "A Brief History of Time: From the Big Bang to Black Holes." The book sold more than 10 million copies.

Today, at 69, Dr. Hawking directs research at the Center for Theoretical Cosmology at the University of Cambridge. He is mostly paralyzed. With a cheek muscle, he signals an electronic sensor in his eyeglasses and thereby chooses from among the words flashing past on a screen attached to his wheelchair. The computer then speaks those words in the metallic voice familiar to Dr. Hawking's legion of fans.

Dr. Hawking came here last month for a science festival sponsored by the Origins Project of Arizona State University. In his lecture, "My Brief History," he spoke of the special joys of scientific discovery. "I wouldn't compare it to sex," he said, "but it lasts longer." The audience roared.

The next afternoon, Dr. Hawking sat for a rare interview.

A week before the meeting, 10 questions had been sent to his daughter, Lucy Hawking, 40. So as not to exhaust her father, who has grown weaker since a near-fatal illness two years ago, Ms. Hawking read them to him over a period of days.

During our meeting, the physicist played back his answers. Only one exchange, the last, was spontaneous.

Q. What is a typical day like for you?

A. I get up early every morning and go to my office where I work with my colleagues and students at Cambridge University. Using e-mail, I can communicate with scientists all over the world.

Obviously, because of my disability, I need assistance. But I have always tried to overcome the limitations of my condition and lead as full a life as possible. I have traveled the world, from the Antarctic to zero gravity. (Pause.) Perhaps one day I will go into space.

Q. There are some experts on A.L.S. who insist that you can't possibly suffer from the condition. They say you've done far too well. How do you respond to this kind of speculation?

A. Maybe I don't have the most common kind of motor neuron disease, which usually kills in two or three years. It has certainly helped that I have had a job and that I have been looked after so well.

I don't have much positive to say about motor neuron disease.

But it taught me not to pity myself, because others were worse off, and to get on with what I still could do. I'm happier now than before I developed the condition. I am lucky to be working in theoretical physics, one of the few areas in which disability is not a serious handicap.

Q. About the Large Hadron Collider, the supercollider in Switzerland, there were such high hopes for it when it was opened. Are you disappointed in it?

A. It is too early to know what the L.H.C. will reveal. It will be two years before it reaches full power. When it does, it will work at energies five times greater than previous particle accelerators.

We can guess at what this will reveal, but our experience has been that when we open up a new range of observations, we often find what we had not expected. That is when physics becomes really exciting, because we are learning something new about the universe.

Q. Though you avoid stating your own political beliefs too openly, you entered into the health care debate here in the United States last year. Why did you do that?

A. I entered the health care debate in response to a statement in the United States press in summer 2009 which claimed the National Health Service in Great Britain would have killed me off, were I a British citizen.

I felt compelled to make a statement to explain the error.

I am British, I live in Cambridge, England, and the National Health Service has taken great care of me for over 40 years.

Q. Scientists at Fermilab recently announced something that one of our reporters described as "a suspicious bump in their data that could be evidence of a new elementary particle or even, some say, a new force of nature." What did you think when you heard about it?

A. It is too early to be sure. If it helps us to understand the universe, that will surely be a good thing. But first, the result needs to be confirmed by other particle accelerators.

Q. The speech you gave the other night here in Tempe, "My Brief History," was very personal. Were you trying to make a statement on the record so that people would know who you are?

A. (After five minutes.) I hope my experience will help other people.

The New York Times