French mining experts discovered the remains of several such natural reactors in Gabon in 1972. By then, science imitating nature, workers in many countries were pouring concrete for water-moderated, man-made nuclear reactors to generate electricity, and six nations were stockpiling atomic and hydrogen bombs.
Two German chemists studying uranium, Otto Hahn and Fritz Strassmann, discovered nuclear fission in Nazi Germany in December 1938, nine months before the beginning of World War II in Europe. When the chemists published their finding the following month, the science community was amazed. No one had ever seen such an energetic reaction: fire one low-energy neutron into a uranium atom and the atom split apart and released a burst of energy 10 million times as intense.
Such ferocious output made it immediately obvious to physicists everywhere that the discovery could lead to a vastly destructive new kind of bomb. Jewish physicists in England and America who had escaped Nazi Germany were horrified. Fearing a German head start, Hungarians Leo Szilard, Eugene Wigner and Edward Teller, plus Albert Einstein, an earlier arrival, alerted Franklin Roosevelt. The president, realizing that possession of such a weapon would be the only defense against an enemy similarly armed, gave the go-ahead for a top-priority research effort. The British, already at war, contributed a detailed proposal, and in October 1941 the Manhattan Project was born.
It cost as much to make the first three bombs as it would cost two decades later to send men to the moon. What began on a benchtop in Germany in 1938 became an industry comparable in scale to the U.S. automobile industry of the day. Vast secret factories went up in Tennessee that drew megawatts of TVA electricity and employed tens of thousands of workers. The Columbia River was partly diverted to cool powerful graphite-and-uranium production reactors in the state of Washington. Tons of uranium ore entered one end of the system; a few grams of pure uranium and the new man-made element plutonium came out the other. Once a week an army security man carried the week’s output in an ordinary suitcase by passenger train to a new secret laboratory high on a mesa at Los Alamos, N.M., where the first bombs were to be built. “Gadgets,” lab director J. Robert Oppenheimer dubbed them when the laboratory set up shop behind barbed wire in April 1943.
Oppenheimer, a charismatic theoretical physicist, guided a crack team of world-class scientists at Los Alamos. The two different bombs they devised over the next 28 months, Little Boy and Fat Man, fissioned baseball-size cores of uranium or plutonium to deliver explosions equivalent to thousands of tons of TNT. Designing such awesome weapons required inventing whole new technologies: electrical detonators with microsecond timing, high explosives shaped into lenses that focused shock waves to compress solid metal, diagnostic cameras spinning a million flames a second, plutonium’s bizarre metallurgy.
The first Fat Man exploded on a tower in a barren stretch of New Mexican desert before dawn on July 16, 1945, confirming the success of this immense commitment of people and resources. “There was an enormous ball of fire which grew and grew and it rolled as it grew,” Columbia University physicist I. I. Rabi remembered. “It looked menacing. It seemed to come toward one.” Rabi saw the test’s deeper portents as well: “A new thing had just been born; a new control; a new understanding of man, which man had acquired over nature.
To recruit his remarkable team, Oppenheimer had whispered that the bombs they would build would not only end World War II but might also end war itself. Certainly they ended the Pacific war. Of the 76,000 buildings in the Japanese port city of Hiroshima, bombed on Aug. 6, Little Boy damaged or destroyed 70,000-48,000 of them totally. Ninety percent of all Hiroshima’s medical personnel were disabled or killed. At least 70,000 people died by the end of the month; more died later of the effects of fire, blast and radiation. A second Fat Man, twice as powerful as Little Boy, similarly decimated Nagasaki on Aug. 9. A third Fat Man was waiting in the wings; Oppenheimer thought he could produce six a month beginning in October. Japanese Emperor Hirohito specifically cited “a new and most cruel bomb” in his historic broadcast of Aug. 15, when he ordered his people to lay down their arms.
Was Oppenheimer right? Did the development of nuclear weapons put an end to war? Not all war, obviously, but world-scale war became increasingly unthinkable after those brutal August shocks. Across the second half of the century–an era one historian has called the “long peace”–tens of thousands of bombs would be built and stockpiled, but in all those years not one was ever exploded in anger.
Why such unprecedented restraint? Because a proliferating balance of terror made nuclear war suicidal. A Soviet scientific team under physicist Igor Kurchatov started small-scale development of an atomic bomb in Moscow early in 1948, after spies in England and the United States alerted Stalin to the Manhattan Project
The Soviet dictator suspected a hoax, but the evidence of Hiroshima and Nagasaki two years later persuaded him to order an all-out Russian effort. By then, two Los Alamos physicists, German emigre Klaus Fuchs and an American, Theodore Alvin Hall, had independently passed detailed plans to the KGB. The British began a bomb project immediately after the Japanese surrendered. France under Charles de Gaulle soon weighed in. Even Sweden launched a small bomb program in those early days but eventually shut it down.
The United States temporized for two years before beginning to improve and stockpile nuclear weapons in earnest: as late as April 1947 there were no working atomic bombs in the American arsenal, though the cold war had begun dividing the world by then and Soviet conventional forces in Europe were expanding. Harry Truman, determined to pay off the war deficit and judging that the world’s only nuclear power could afford to reduce its conventional forces, cut the defense budget to the bone. When the Pentagon realized in 1948 that the civilian Atomic Energy Commission was legally required to build as many bombs as the military certified it needed–and that the commission would bear the expense–official military requirements soared from a few hundred bombs to, eventually, tens of thousands. The Soviet Union was a serious threat, but “overkill,” as it came to be called–making the rubble bounce–had more to do with interservice rivalry in both the United States and the U.S.S.R. than with military reality.
When U.S. “sniffer” planes picked up fallout from the first Soviet atomic-bomb test, on Aug. 29, 1949, two years ahead of CIA predictions, Washington panicked: suddenly Russia had nuclear potential to go with its massive conventional advantage. A few wise heads, including Rabi, saw that nuclear parity might make the Soviets amenable to international control and called for renewed diplomacy. But hawks, encouraged by an ambitious Edward Teller, clamored for a new, unique capability: the hydrogen bomb. The Joint Chiefs heard about the hydrogen bomb for the first time on Oct. 13 and decided on the spot that the United States had to build it before the Russians did. Truman concurred, announcing his decision on Jan. 31,1950. “I never forgave Truman,” Rabi would say bitterly. “For him to have alerted the world that we were going to make a hydrogen bomb at a time when we didn’t even know how to make one was one of the worst things he could have done.” Teller had sold Washington a pig in a poke.
Inventing the hydrogen bomb turned out to be a far harder job than the atomic bomb had been. Calculations on some of the earliest digital computers proved that the design Teller had banked on was a dud. He was near despair when an urbane Polish mathematician at Los Alamos, Stanislaw Ulam, showed him the way to a breakthrough. The two-stage design that resulted, tested on the Pacific atoll of Eniwetok on Nov. 1, 1952, yielded a terrifying 10.4 megatons–a thousand times the power of the Hiroshima bomb. The Soviets worked out multiple staging in 1955 and tested a 58-megaton monster in 1961, the largest ever exploded. British, French and Chinese hydrogen bombs followed. Israel, India, Pakistan and South Africa developed more modest atomic capabilities. . . . .
The motive for going nuclear was always defensive, though national prestige also figured in. The United States built the bomb because it feared a German lead, Soviet Russia to counter the United States, Britain and France to acquire an independent anti-Soviet deterrent, China to counter the United States and the U.S.S.R., India to counter China, Pakistan to counter India, Israel because it was surrounded by hostile Arab states, apartheid South Africa to ward off black Africa. Before it gave up power, the white South African government dismantled its small nuclear arsenal, the only act of unilateral nuclear disarmament yet recorded.
Every U.S. president since Truman and every Soviet leader after Stalin said publicly that using nuclear weapons was inconceivable, and so it has proved to be. Not deadlock, as in Korea, nor even defeat, as in Vietnam and Afghanistan, would ever justify escalation. The danger was too great. “In the real world of real political leaders,” John Kennedy’s and Lyndon Johnson’s national-security adviser, McGeorge Bundy, wrote in 1969, “… a decision that would bring even one hydrogen bomb on one city of one’s own country would be recognized in advance as a catastrophic blunder; ten bombs on ten cities would be a disaster beyond history; and a hundred bombs on a hundred cities are unthinkable.
Small, cheap and portable, with essentially unlimited destructive capacity, nuclear weapons deny advantage to aggressor and defender alike. Lesser wars continue and will continue until the world community is sufficiently impressed with their futility to forge new instruments of protection and new forms of citizenship. But world war has at least been revealed to be a historical interlude in human history that began when the industrial capacity of entire nations could be mobilized for war and ended when a few hundred bombs could destroy that capacity in a matter of hours. In the long history of human slaughter that is no small achievement.
An equal achievement has been the application of nuclear fission to peaceful purposes. Nuclear power plants in 32 countries today supply more than 17 percent of the world’s electricity. Americans have been taught to fear nuclear power, but the United States has more installed capacity than any other country. France is second–75 percent of French electricity is nuclear, which has reduced French air pollution fivefold–followed by Russia and Japan. Chernobyl was an anomaly: a flawed design, illegal in the West, recklessly mishandled by a criminal regime.
Air pollution, increasing demand and depletion of fossil fuels make it a sure bet that natural gas and nuclear power will be the prime sources of energy in the 21st century: China, South Asia and the industrializing Third World have already begun ambitious nuclear power programs. Nuclear reactors breed plutonium as they burn uranium; the “spent” fuel that affluent America calls nuclear waste and prepares to bury is a nearly unlimited source of energy that other nuclear nations value and recycle. (U.S. recycling was halted in 1979 to discourage weapons proliferation, but no nuclear power make s bombs from reactor-grade plutonium, and no terrorist group could–it’s unreliable.) Like the natural reactors of Gabon, power reactors can transmute nuclear waste- including the tons of plutonium removed from the tens of thousands of nuclear weapons that the United States and Russia are dismantling as the arms race winds down-to less dangerous forms.
“The physicists have known sin,” Robert Oppenheimer once famously said. He meant their pure science had fallen into a world of hard consequences. So long as civilization continues, we will have knowledge of how to destroy ourselves in nuclear war. But a world without nuclear weapons isn’t a pipe dream; the time will come when deterrence means mothballed factories capable of delivering warheads in three months rather than nuclear submarines capable of delivering warheads in half an hour. Self-interest will dictate the stand-down, because nations growing more prosperous in a nuclear-powered world will have ever more to lose. That prospect and all this history, taken together, mean that the release of nuclear energy was arguably the most important human discovery since fire..
