Missing physics, missing youth

Originally published in PAW’s April 20, 2005, issue

Alan Lightman ’70 is a physicist and author. He has taught astronomy and physics at Harvard and MIT and is now an adjunct professor of humanities at MIT. His novels include the best-selling Einstein’s Dreams and The Diagnosis, which was a finalist for the National Book Award. This essay appears in his latest book, A Sense of the Mysterious. (Copyright © by Einstein Dreams Inc. and published by arrangement with Pantheon Books, a division of Random House Inc.)

When I turned 35, I wrote an essay for the New York Times Magazine about my distressing awareness that I would soon be an old man in my field. That field was theoretical physics, where people do their best work at a famously young age. Now, 16 years later, having long since given up physics for a profession in which I am still young, I find myself looking back on my life as a scientist and what I so miss.

I miss the purity. Theoretical physicists, and many other kinds of scientists, work in a world of the mind. It is a mathematical world without bodies, without people, without the vagaries of human emotion. A physicist can imagine a weight hung from a spring bouncing up and down and fix this mental image with an equation. If friction with air becomes an unwanted nuisance, just imagine the weight in a vacuum.

Much of science, in fact, is built on these pure pictures of the mind. And the equations themselves are beautiful. The equations have a precision and elegance, a magnificent serenity, an indisputable rightness. I remember so often finding a sweet comfort in my equations after arguing with my wife about this or that domestic concern or fretting over some difficult decision in my life or feeling confused by a person I’d met. I miss that purity, that calm.

Of course, other occupations also deal with ideas. But the ideas are often complicated with the ambiguity of human nature. The exquisite contradictions and uncertainties of the human heart do indeed make life interesting; they are why God held the apple in front of Eve and then forbade her to eat it, they inspire artists and art, they are why the poet Rainer Maria Rilke wrote that we should try to love the questions themselves.

All that is necessary and good. But I miss the answers. I miss the rooms I could enter, the language that sounded clear as a struck bell.

I miss the exhilaration of seeing brilliant people at work, watching their minds leap right in front of me, not the brooding intelligence of writers, but an immediate mental agility, pole vaults and somersaults and triple axels on the ice. Richard Feynman once walked into my tiny office at Caltech and, in 20 minutes at the blackboard, outlined the basic equations for the quantum evaporation of spinning black holes, an ingenious idea that had just occurred to him on the spot. When I was stymied by a tough astrophysics problem at Cornell, the great theoretician Edwin Salpeter, while lying on the floor of his living room with back pain, instantly drew an analogy between the slow drift of stars orbiting a disruptive mass and the random motion of a drunk stumbling around on a street with an open sewer hole.

Others I watched from the front row: the British astrophysicist and astronomer royal Martin Rees, the Nobel Prize-winning particle physicist Steven Weinberg. In the presence of these minds I felt humbled as well as excited. I miss the humility; it made me crouch down and observe. I listened more than I talked. I took in.

Most of all, I miss the intensity. I miss being grabbed by a science problem so that I could think of nothing else, consumed by it during the day and then through the night, hunched over the kitchen table with my pencil and pad of white paper while the dark world slept, tireless, electrified, working on until daylight and beyond.

Every creative field has its moment of inspiration, the struggle to that moment, and then the surge of insight. In most occupations, the aftermath is a slow working-out of the idea. As a writer, even when I am writing well, I cannot write more than six hours at a time. After that I am exhausted, and my vision has become clouded by the inherent subtleties and uncertainties of the work. Then I must wait for the words to shift and settle on the page and my own strength to return.

But as a scientist, I could be gripped for days at a time. I could go for days without stopping. Because I wanted to know the answer. I wanted to know the telltale behavior of matter spiraling into a black hole, or the maximum temperature of a gas of electrons and positrons, or what was left after a cluster of stars had slowly lost mass and drawn in on itself and collapsed.

When in the throes of a new problem, I was driven night and day, compelled because I knew there was a definite answer, I knew that the equations inexorably led to an answer, an answer that had never been known before, an answer waiting for me. That certainty and power and the intensity of effort it causes I dearly miss. It cannot be found in most other professions.

Sometimes, I wonder if what I really miss is my youth. Purity, exhilaration, intensity — these are aspects of the young. In a way, it is not possible at age 50 for me to look back on myself in my 20s and early 30s and understand anything more than the delicious feeling of immortality, the clarity of youth, the feeling that everything was possible.

I do miss my youth. And now, as a writer still finding my stride, while I can reasonably expect another couple of decades to thrive, I know that this second profession too will come to an end, that I will inevitably dwindle down to the physical as well as mental and artistic end, the final end. Of course, I want to be young again.

But given a chance to start over, I would do just what I did, to be not only a young man in the shimmering of youth but a scientist. I would want again to be driven day and night by my research. I would want the beauty and power of the equations. I would want to hear that call of certain truth, that clear note of a struck bell.