To generations of Caltech students, Feynman was much more than a great physicist and superlative teacher. He was a fun-loving, bongo-playing practical joker, who drove thru the streets of Pasadena in a truck adorned with Feynman diagrams ( of atomic particle motion ) and lectured on to to pick locks and break into safes.

feynman was physics with a human face -- a man as famous for his escapades in topless bars as his achievements in quantum field theory. What endered him to everyone -- those who knew him personally and those who learnt of him thru his books -- was his humanness. To students of physics the world over, he was living proof .. and proof is needed ... that to get on in the science you don't have to have ice water for blood and the mind of a Cray computer.

the most gifted physicist of his generation, Feynman shared the l965 nobel prize for physics with Julian Schwinger and Shin'chiro Tomonaga for his work on the theory of quantum electrodynamics. Quantum electordynamics, or QED, describes how electrons and positrons interact with photons and is, to this day, the most successful theory in physics.

feynman had a compulsive desire to unravel puzzles of all kinds and physics to him, was the ultimate puzzle. He delighted in figuring out what made things tick, from the workings of supposedly secure safes at Los Alamos, where he worked on the atomic bomb project in the l940's to the secrets of superfluid liquid helium; from the intricacies of a Mayan codex to the precise mechanisms of radioactive beta decay.

feynman's approach to physics was unique. While theoreticians such as Schwinger painstakingly manipulate pages of algebra in solving problems Feynman played happily in is head with the nuts and bolts, cogs and wheels of the new physics. With his formidable intuition he honed in on solutions, visualizing them before working out the maths. Nowhere is this approach more striking than in the Feynman diagrams which he invented to represent particle interactions, and which are the standards tools in physics today.

when Feynman died of cancer on Feburary l6, l986, aged 69, it was the end of a long battle against the disease. Feynman was already living on borrowed time when in l982, I arrive at Caltech as a graduate student. Then, he was recovering from major surgery, and it was a shock, at first, to see how much older and frailer he was than the man I had seen grinning and playing the bongos on the flealeaf of the Feynman Lectures on physics.

but Feynman bounced back from that particular setback. The man who had a penchant for hugging his secretaries, and sunbathing nude on the roof of the physics building, had a lot of living left to do. Behind the wrinkled visage, china-blue eyes still twinkled with gentle mischief. And the smile never left the face.

feynman liked people. It didn't matter whether you were a professor of physics or a gardener in the process of mowing Caltech's lawns, Feynman had time for you. Just as he was interested in all thing, he was interested in all people. There was one condition though, and that was that you be yourself, that you approached the man and not the myth. The Nobel Prize always irked him. It had the advantage that he got to buy a beach house with the money but the disadvantage that people flocked to his lecture just to say they had seen him, not to listen to what he had to say.

feynman's lectures were immensely popular. They ran the gamut of subjects from quantum chromodynamics, the thoery of quarks and gluons to the rudiments of picking locks. This latter subject, though immensely popular with the students, didn't go down well with the faculty. They found themselves unable to lock anything beyond the prying fingers of undergraduates.

things did always go smoothly in Feynman's lectures, however. There was the day in l984, for instance, when he completely lost his marbles. He turned up to lecture and, to everyone's amazement, talked utter gibberish.

it all happened because the night before Feynman had gone out to buy himself a home computer and had tripped on a kerb (curb). He had fallen and banged his head. Hour by hour, the pressure of blood inside his skull had increased, affecting his reason. Fortunately, when doctors drilled holes in his skull to relieve the pressure, he was right as rain.

feynman said afterwards that he had known something was wrong. The morning before the class, he had looked at his lecture notes and been unable to understanding them. He had assumed that he was going senile. Of course, the said, everyone knows that you don't go senile overnite, It was one of the few times in his life when logic deserted him.

the stories about Feynman are legion. Ralph Leighton, Feynman's friend and bongo drumming partner, put together the ancedotes in ( the book ) Surely You Must be Joking, Mr.Feynman!, subtitled "Adventures of a Curious Character."

The book, published in Britian by Counterpoint, was a bestseller in the US. In the preface, Leighton writes:

"That one person could have so many wonderfully crazy things happen to him in one life is sometimes hard to believe. That one person could invent so much innocent mischief in one life is an inspiration."

mischief such as breaking into safes at Los Alamos to test the security system. Crazy little things like playing for a bare-footed samba band on Copacabana beach while at a Brazilian university, and testifying in the court on behalf of a topless restaurant.

the newspaper had a field day over that one. Feynman was the only customer prepared to defend the Pasadena restaurant when someone tried to close it down. He liked to work there on physics problems and to sketch the female form. In courts, when he was asked how often he visited the establishment, he answered, five or six times a week. Not surprisingly, it got into the papers under the headline: "Caltech professor goes to see topless dancing six times a week."

more recently, in l986, Feynman hit the headlines when he served on the committee investigating the Challenger disaster. The only person on the committee who wasn't associated with NASA, he proved to be the agency's toughtest critic, accusing if of "playing Russian roulette" in its approach to safety. And for some time, Feynman refused to put his name to the committee's report on the accident.

briefed by engineers at Caltech's Jet Propulsion Laboratory before flying to Washington, Feynman saw straight to the heart of the problem. On the second line of his notes that day, he scribbled that there might be a problems with the shuttle's O-rings. The O=rings, the rubber seals between sections of the solid=fuel boosters, were subsequently shown to have allowed hot gas to leak and burn a hole thru the tank containing the explosive liquid hydrogen. It was a problem that NASA's engineers had warned about but NASA's managers had chosen to ignore.

with characteristic showmanship, Feynman demonstrated the problem before a Tvee audience. Taking a sample of O-ring, he clamped it, then put it for a while in a glass of iced water. When he pulled it out and released the clamp, the rubber failed to spring back into shape: it had lost all its resilience.

after serving on the commission for far longer than he expected ... two years rather than the six months he anticipated ... Feynman returned to Caltech, and the academic world. He continued to do research and teach, and was teaching ... a course on the theory of quarks and gluons ... just before he died.

feynman was a man remarkably at peace with himself. Like Einstein before him, he had been afforded a glimpse of the face of God. For a brief moment, he said, he had known a law of nature ... a description of beta decay ... that no one else in the world had known. No amount of money can buy that feeling and the huge majority of us can only look on from the outside and speculate on what that feeling was like.

i have one last anecdote about Feynman. I include it not because it has any deep significance, thou it does, I think, say something about him. It's about the time he wrote to my mum ( the obituary author is British ).

in l982, the BBC screened a profile of Feynman in its HORIZON series. My mother watched from beginning to end. Now, there's nothing extrordinary about that, except that my mother had never shown interest in ANY scince programme, or anything to do with science for that matter ( I never have been able to explain to her satisfaction, why people in Australia don't just fall off into space ). However, later, when I was at Caltech, I had an idea. I would go to Feynman, explain that my mother had watched him on tvee, and ask him whether he would help me out by dropping her a note. If he did, I reasoned naively, then perhaps the next time I tried to explain to my mother how we know that the Earth is round or the sky is blue, she might be more receptive.

there was something about Feynman that said he was approachable. I KNEW, tho I had never spoken to him, that he would not think my request a frivolous one. (What is it about some people, I wonder, that makes you feel, the minute you see them, that you know them?).

anyhow, the upshot was that Feynman did drop my mother that note. It said:

"Dear Mrs Chown, Ignore your son's attempts to teach you physics. Physics isn't the most important thing. Love is.