Джеймс Глик - Genius - The Life and Science of Richard Feynman

A page from one of Feynrnan's teenage notebooks.

A month before he turned fifteen he covered a page with an elated inch-high scrawl:

THE MOST REMARKABLE

FORMULA

IN MATH.

eiπ + 1 = 0

(FROM SCIENCE HISTORY OF THE UNIVERSE)

By the end of this year he had mastered trigonometry and calculus, both differential and integral. His teachers could see where he was heading. After three days of Mr.

Augsbury’s geometry class, Mr. Augsbury abdicated, putting his feet up on his desk and asking Richard to take charge. In algebra Richard had now taught himself conic sections and complex numbers, domains where the business of equation solving acquired a geometrical tinge, the solver having to associate symbols with curves in the plane or in space. He made sure the knowledge was practical. His notebooks contained not just the principles of these subjects but also extensive tables of trigonometric functions and integrals—not copied but calculated, often by original techniques that he devised for the purpose. For his calculus notebook he borrowed a title from the primers he had studied so avidly, Calculus for the Practical Man .

When his classmates handed out yearbook sobriquets, Feynman was not in contention for the genuinely desirable Most Likely to Succeed and Most Intel ectual. The consensus was Mad Genius.

All Things Are Made of Atoms

The first quantum idea—the notion that indivisible building blocks lay at the core of things—occurred to someone at least twenty-five hundred years ago, and with it physics began its slow birth, for otherwise not much can be understood about earth or water, fire or air. The idea must

have seemed dubious at first. Nothing in the blunt appearance of dirt, marble, leaves, water, flesh, or bone suggests that it is so. But a few Greek philosophers in the fifth century B.C. found themselves hard pressed to produce any other satisfactory possibilities. Things change

—crumble, fade, wither, or grow—yet they remain the same. The notion of immutability seemed to require some fundamental

immutable

parts.

Their

motion

and

recombination might give the appearance of change. On reflection, it seemed worthwhile to regard the basic constituents of matter as unchanging and indivisible: atomos —uncuttable. Whether they were also uniform was disputed. Plato thought of atoms as rigid blocks of pure geometry:

cubes,

octahedrons,

tetrahedrons,

and

icosahedrons for the four pure elements, earth, air, fire, and water. Others imagined little hooks holding the atoms together (of what, though, could these hooks be made?).

Experiment was not the Greek way, but some observations supported the notion of atoms. Water evaporated; vapor condensed. Animals sent forth invisible messengers, their scents on the wind. A jar packed with ashes could stil accept water; the volumes did not sum properly, suggesting interstices within matter. The mechanics were troubling and remained so. How did these grains move? How did they bind? “Cloudy, cloudy is the stuff of stones,” wrote the poet Richard Wilbur, and even in the atomic era it was hard to see how the physicist’s swarming clouds of particles could give rise to the hard-edged world of everyday sight and touch.

Someone who trusts science to explain the everyday must continual y make connections between textbook knowledge and real knowledge, the knowledge we receive and the knowledge we truly own. We are told when we are young that the earth is round, that it circles the sun, that it spins on a tilted axis. We may accept the knowledge on faith, the frail teaching of a modern secular religion. Or we may solder these strands to a frame of understanding from which it may not so easily be disengaged. We watch the sun’s arc fal in the sky as winter approaches. We guess the time from the shadow of a lamppost. We walk across a merry-go-round and strain against the sideways Coriolis force, and we try to connect the sensation to our received knowledge of the habits of earthly cyclones: northern hemisphere, low pressure, counterclockwise. We time the vanishing point of a tal -masted ship below the horizon. The sun, the winds, the waves al join in preventing our return to a flat-earth world, where we could watch the tides fol ow the moon without understanding.

All things are made of atoms —how much harder it is to reconcile this received fact with the daily experience of solid tables and chairs. Glancing at the smooth depressions worn in the stone steps of an office building, we seldom recognize the cumulative loss of invisibly smal particles struck off by ten mil ion footfal s. Nor do we connect the geometrical facets of a jewel to a mental picture of atoms stacked like cannonbal s, favoring a particular crystal ine orientation and so forcing regular angles visible to the naked eye. If we do think about the

atoms in us and around us, the persistence of solid stone remains a mystery. Richard Feynman asked a high-school teacher (and never heard a satisfactory reply), “How do sharp things stay sharp al this time if the atoms are always jiggling?”

The adult Feynman asked: If al scientific knowledge were lost in a cataclysm, what single statement would preserve the most information for the next generations of creatures? How could we best pass on our understanding of the world? He proposed, “ All things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another ,” and he added, “In that one sentence, you wil see, there is an enormous amount of information about the world, if just a little imagination and thinking are applied.”

Although mil ennia had passed since natural philosophers broached the atomic idea, Feynman’s lifetime saw the first generations of scientists who truly and universal y believed in it, not just as a mental convenience but as a hard physical reality. As late as 1922 Bohr, delivering his Nobel Prize address, felt compel ed to remind his listeners that scientists “believe the existence of atoms to be proved beyond a doubt.” Richard nevertheless read and reread in the

Feynmans’ Encyclopaedia Britannica that “pure chemistry, even to-day, has no very conclusive arguments for the settlement of this controversy.” Stronger evidence was at hand from the newer science, physics: the

phenomenon cal ed radioactivity seemed to involve the actual disintegration of matter, so discretely as to produce audible pings or visible blips. Not until the eighties could people say that they had final y seen atoms. Even then the seeing was indirect, but it stirred the imagination to see shadowy

globules

arrayed

in

electron-microscope

photographs or to see glowing points of orange light in the laser crossfire of “atom traps.”

Not solids but gases began to persuade seventeenth-and eighteenth-century scientists of matter’s fundamental granularity. In the heady aftermath of Newton’s revolution scientists made measurements, found constant quantities, and forged mathematical relationships that a philosophy without numbers had left hidden. Investigators made and unmade water, ammonia, carbonic acid, potash, and dozens of other compounds. When they careful y weighed the ingredients and end products, they discovered regularities. Volumes of hydrogen and oxygen vanished in a neat two-to-one ratio in the making of water. Robert Boyle found in England that, although one could vary both the pressure and the volume of air trapped at a given temperature in a piston, one could not vary their product.

Pressure multiplied by volume was a constant. These measures were joined by an invisible rod—why? Heating a gas increased its volume or its pressure. Why?