How did it feel to win the Nobel Prize for Physics and in what sense has it changed your life?

It was quite a surprise receiving the phone call that morning. It might have been less of a surprise some years earlier, but it was very gratifying nonetheless. Having received the prize does in one way or another consume a fair amount of one’s time. One becomes in a sense a proxy for a great many colleagues. If one takes up the responsibilities implicit in that role it could become very difficult to continue creative work. That is a kind of threat to the careers of younger recipients. There is something merciful in receiving the prize later in life.

There is something merciful in receiving the prize later in life.

Are you surprised by all of the research and applications that have sprung from your work on quantum optics?

It’s always impressive to see applications spring from one’s work. They frequently take off in directions one would never have anticipated. What has been most fascinating has been the development of sensitively controlled ways of generating special quantum states involving one or a few photons. The “entangled” states in particular show exciting promise as a basis for quantum computation.

What do you think are the most important unanswered questions in quantum mechanics?

Quantum mechanics doesn’t seem to contain many mysteries anymore, now that we have truly learned to answer its questions and to live with it. But I can’t believe we won’t have still deeper lessons to learn in the future when theory is unable to cope with the results of experiments. The most obvious place for that to happen is in the less explored areas of high-energy physics. To find such suggestions in low-energy physics will evidently require unprecedented accuracy.

Can you describe how you developed an early interest in science, particularly through your experiences at the Bronx High School for Science?

I had an early interest in astronomy, which led me to grind the mirror for a reflecting telescope and then to build a number of optical instruments before I went to high school. The New York high schools of that era had benefited from the depression years by being able to hire as teachers a whole generation of capable young people who seemed to have no future in other occupations after their own college educations.

Do you still remember your teachers?

My interest in mathematics was raised considerably by a teacher called Samuel Altwerger who encouraged me to learn calculus halfway through high school. He was convinced that the subject was far less formidable than it was reputed to be. He was right. Doing that saved me about two years of college math, and made it possible for me to skip the intermediate physics courses in college and proceed to the graduate courses directly. That’s how I was able to work at Los Alamos during the war before I had graduated.

How did you feel about being involved in the Manhattan Project at such a young age?

December 1940

The organization of the Manhattan Project must have had a desperate time finding people not yet engaged in war work who were willing to relocate to the middle of New Mexico. Being 18 and having taken most of the graduate courses was a real advantage in those respects. It was a strange feeling being part of a mature theoretical division under Hans Bethe, but very few people on the project were as old as its leaders, who were almost all under 40.

Were you aware of the project’s goal when you signed up, and how did you feel when you found out?

The nuclear projects were kept as dark secrets during the war. The best evidence I had on what was being done was the absence of any open mention of fission after 1940. My guess, based on that and a couple of scattered hints, some of them incorrect, was that they were trying to get a chain reaction to work. In fact they had already accomplished that over a year earlier. I hadn’t guessed that Los Alamos was working to build a bomb, and I was quite taken aback to learn that when I arrived.

It took some months to grow accustomed to the idea, and the wish to put an end to the long sequence of massive air raids first over Britain and then over Germany played an important role. It seemed clear that the Germans could be developing their own bomb, and that too added to the motivation. I can’t remember hearing any talk at all of Japan as a threat in that connection.

I hadn’t guessed that Los Alamos was working to build a bomb, and I was quite taken aback to learn that when I arrived.

Of all the great physicists you have worked alongside, who was the most inspirational?

It’s awfully difficult to say who I admired most among the leaders. Both Fermi and Bethe were extraordinarily effective in zeroing in on the essential points and wasting no time on affectation of any sort. They seemed, as mature scientists, to have little patience with elegant ways of deriving their conclusions, and to regard those as a waste of effort. As an immature scientist, I’d have to admit to deriving joy from a particularly neat bit of mathematics or way of arriving at a result. Fermi had started out in life as a mathematician, and must have learned to resist that strong temptation.

You have had a lot of involvement with the Ig Nobel prizes – do you think it’s important for scientists to keep a sense of humour about their work?

The Ig Nobel ceremonies are an annual bit of fun and a pin prick to inflated personalities. Their awards are often clever and frequently funny, though those categories don’t always overlap. I do find that some features of the presentation have become a bit ritualistic over the years, particularly those that have least relation to what is going on in contemporary science.