It was a warm fall day when Alexander Sachs walked into the lush, green grounds of the White House, but his thoughts were far from mellow.
It was Oct. 11, 1939, and he was charged with an urgent mission, bearing a letter that he, and a gaggle of little-known foreign scientists, hoped would save the civilized world, abruptly plunged into war with Nazi Germany.
The 鈥淓instein letter,鈥 as it鈥檚 now known, was signed by the revered discoverer of the , which revolutionized physics, cosmology and astronomy. And Albert Einstein鈥檚 signature on the two-page typed document would play a historic role in a drama that would stretch for nearly six years and end with the dropping of the deadliest weapon ever imagined in the mid-20th century: the atomic bomb.
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For Sachs, a 46-year-old Russian-born Harvard graduate and former economic adviser to President Franklin Roosevelt, the audience with the overburdened leader was of crucial importance. Germany and the Soviet Union had invaded Poland, all of Europe was on a knife鈥檚 edge and the brief era of post-First World War stability was over.
The letter Sachs carried 鈥 written and painstakingly revised over a period of weeks 鈥 was largely the work of Hungarian 茅migr茅 Leo Szilard, a 41-year-old physicist who had fled the Nazis in the early 1930s for England and discovered the theory of a nuclear chain reaction.
It called for 鈥渨atchfulness鈥 and 鈥渜uick action鈥 on the imminent development of a powerful new generation of bombs based on uranium and capable of destroying huge swaths of territory. America, it noted, had only small supplies of poor-quality uranium, while Germany had a grip on large stocks from seized Czechoslovakian mines 鈥 a clear warning that Adolph Hitler planned to develop an atomic bomb.
The letter urged Washington to secure a supply of uranium ore. And it asked Roosevelt to appoint a co-ordinator to update the government about chain reaction work by scientists in America and help speed up experimental work in university labs.
It was, in fact, a carefully worded call to atomic arms, one that has echoed down decades of praise and protest, and pointed the way to unleashing a fearsome force that changed the world鈥檚 geopolitical order.
With the dawn of the Atomic Age, says Nobel laureate and University of 海角社区官网chemist John Polanyi, 鈥渨e were in on something as important as when fire was discovered. The era changed as surely as the Stone Age led to the Bronze Age.鈥
The vastness of the change exploded into public consciousness with the August 1945 bombing of Hiroshima, which vapourized humans into terrifying shadows in seconds. But the events that led to the atomic bomb were far less dramatic, meandering over two continents for more than a decade, unnoticed by most non-scientists.
鈥淏efore the war, scientists often said they thought of physics as almost a spiritual discipline because it seemed to have so little relationship to the practical world of machines and bombs,鈥 says Richard Rhodes, author of the Pulitzer Prize-winning history The Making of the Atomic Bomb.
Szilard himself had little idea of how a nuclear chain reaction might be achieved when the theory came to him in London, before he emigrated to New York. Nor was he immediately aware of its potential power.
That dawned on him in 1934, after spending a sunny afternoon on the lawn of Michael Polanyi鈥檚 home in Manchester. The eminent scientist and philosopher, father of John Polanyi, was a friend and confidante with whom Szilard could discuss his radical theories without being labelled a fantasist.
But after returning to London, Szilard fired off an embarrassed telegram: 鈥渉e had sat in our garden calculating the temperature that would be reached by an atomic bomb,鈥 said John Polanyi. But on reflection, Szilard had drastically underestimated its power.
鈥淭emperature obviously about 1,000 to 10 thousand million centigrade,鈥 he wrote in his neat, methodical script.
Szilard was not the only scientist working on the nuclear issue. Italian expat Enrico Fermi won a Nobel Prize for landmark discoveries of new radioactive elements, and producing nuclear reactions with slow neutrons. Scientists in Berlin were experimenting with subatomic particles. For Szilard, the question was who would be the first to produce an atomic bomb.
Enter Einstein.
In the summer of 1939, Szilard was preoccupied with uranium 鈥 which he believed would be the crucial ingredient in a bomb. And he worried that Hitler would buy up large supplies from the Belgian-ruled Congo.
Einstein, who once collaborated with him on an invention in Berlin, was now world famous, the poster boy for a science that everyone revered and almost no one could understand.
Furthermore, he knew Queen Elisabeth of Belgium, and could warn her of the dangers of allowing German purchases of uranium.
On July 16, with fellow physicist Eugene Wigner 鈥 who also worried about Germany鈥檚 atomic ambitions 鈥 Szilard set out by car for the Long Island summer cottage where Einstein was vacationing. But the two brilliant scientists were soon lost, bumbling around the back roads with no exact destination.
鈥淲e were at the point of giving up,鈥 Szilard confessed to Rhodes, 鈥渨hen I saw a boy aged maybe 7 or 8 standing on the curb. I leaned out of the window and (said) 鈥楽ay, do you by any chance know where Professor Einstein lives?鈥 The boy knew that and he offered to take us there.鈥
Einstein, shock-haired and dishevelled as his portraits, greeted them from his porch. But the great theoretician was nonplussed by their request: he had never considered a chain reaction.
When Szilard explained 鈥 an explosive chain reaction could be produced in uranium layered with graphite, by neutrons released by nuclear fission 鈥 Einstein responded, 鈥淚 never thought of that!鈥
But, Szilard told Rhodes, 鈥渉e was very quick to see the implications and was perfectly willing to do anything that needed to be done.鈥 Instead of writing the queen, he suggested a member of the Belgian cabinet.
However, the three scientists realized they should not act on their own on such a crucial matter of national security: a cover letter should be obtained from the U.S. State Department. Einstein and Szilard drafted, and revised, a number of explanatory letters they hoped to dispatch to officials in Washington.
It was no small matter for a group of foreign-born scientists, even under the signature of Einstein. A go-between was needed.
Szilard contacted Sachs, a biologist and economist who had gained Roosevelt鈥檚 ear. After digesting the contents of the letter, Sachs convinced Szilard that instead of wading into the bureaucracy, he should reach for the top 鈥 approaching the president himself.
It was a bold plan. But Roosevelt had much on his mind. By the time the scientists鈥 letter had been revised 鈥 with added input from physicist Edward Teller 鈥 the Nazis had , and on Sept. 3, Britain and France declared war. The Atlantic naval battle began, and France prepared for a German invasion. Canada, meanwhile, declared war on Germany, while the U.S. remained neutral until December 1941.
The mounting crisis raised the scientists鈥 anxiety level. Although a long-time pacifist, Einstein feared Germany鈥檚 growing belligerence. As days went by without progress from Sachs, he called for quicker action to bring the atomic threat to Roosevelt鈥檚 attention.
Sachs had hung back in the hope of gaining a lengthy meeting to plead their case with the president. But as the exasperated scientists gave him an ultimatum for delivering the letter, he at last departed for Washington.
On arrival at the White House on Oct. 11, things did not go smoothly. At first, Roosevelt鈥檚 aide, Gen. Edwin Watson, kept him waiting, while he and his staff reviewed Sachs鈥檚 agenda. 鈥淲hen he was convinced that the information was worth the president鈥檚 time, Watson let Sachs inside the Oval Office,鈥 wrote Rhodes.
Once inside, Sachs applied all his shrewd ingenuity to his task. After drinking a glass of the president鈥檚 rare Napoleon brandy, he launched into an amateur鈥檚-eye view of the Einstein-Szilard letter, which he had rewritten for the occasion.
In about 800 words, he explained the power of nuclear energy for electrical supplies, medical uses 鈥 and 鈥渂ombs of hitherto unenvisaged potency and scope.鈥 He urged making arrangements with Belgium to obtain uranium supplies, and suggested that private foundations and American industry might be willing to share the cost of development with the government. And he asked Roosevelt to appoint a liaison official and committee to communicate with the scientists and U.S. administration.
The summary neatly covered all the political, economic and scientific bases. But it may have been Sach鈥檚 improvised ending that won over the president.
In it he quoted from a lecture by the British scientist Francis Aston, who declared that nothing could prevent the power of 鈥渟ubatomic energy鈥 from being harnessed for better or worse, and that we 鈥渃an only hope that (mankind) will not use it exclusively in blowing up his next-door neighbour.鈥
Roosevelt immediately grasped the point. 鈥淲hat you are after is to see that the Nazis don鈥檛 blow us up,鈥 he said. With that, he called for action.
The atomic project started auspiciously. Sachs met with Bureau of Standards director Lyman Briggs, and a first meeting of the Advisory Committee on Uranium was set up within 10 days.
But there Washington鈥檚 drive for an atomic bomb hit a roadblock 鈥 stalled until 1940, when the British government turned over vital nuclear secrets developed by 茅migr茅 scientists. 鈥淎mong them was a summary saying not only that a bomb was possible, but how you鈥檇 go about building one,鈥 said Rhodes.
Even so it would be more than a year before the National Academy of Sciences submitted a report that Roosevelt approved, and which led to the Manhattan Project, launched in 1942, and the first atomic bomb.
Why did Briggs pull back on America鈥檚 early development of a bomb? 鈥淗e was extremely concerned about security and he put the letter in the safe and locked it up,鈥 said Rhodes. 鈥淭here was also a lot of pre-war inertia on the part of the U.S. scientific establishment. So not much got done out of the Sachs effort to get the letter to Roosevelt.鈥
Now, the expert consensus is that the Einstein letter, however iconic, played a small role in raising the mushroom cloud over Hiroshima.
鈥淭he Uranium Committee was only a precursor organization to the Manhattan Project,鈥 said Alex Wellerstein of the Stevens Institute of Technology in New Jersey, in an email. 鈥淭he real work on the bomb did not start until several years later when a totally different group of scientists took over that work and pushed it into a new phase of development.鈥
Szilard, Teller and Wigner did take part in the Manhattan Project 鈥 although Szilard vigorously opposed the plan to drop an atomic bomb on Hiroshima, and led a petition against it. But Einstein, ironically, was barred from secret government research because his background as a pacifist who opposed the war in Germany made him 鈥渦nreliable.鈥
Einstein had turned against war early in life. But like other scientists who became dedicated anti-nuclear activists after Hiroshima and Nagasaki, he felt revulsion for the burgeoning atomic arsenals that resulted from the Manhattan Project, and threatened the future of the world.
Even his small part in the development of the bomb filled him with regret.
Years later, at Princeton University, recounts John Polanyi, 鈥淓instein said if he鈥檇 known what his involvement would have led to he would have become a plumber instead.鈥
