E=mc2 (29 page)

The United States had an army . . . below the tenth rank . . . : How much a backwater America still was—both intellectually, and militarily—in the late 1930s is often overlooked. If anything, it was the U.S. experience in running such administrative/military efforts as the Manhattan Project that contributed to the triumphantly confident postwar view.

11. Norway

. . . already was a perfectly sound heavy water factory . . . [in] Norway: It was actually a fertilizer factory, attached to a large hydroelectric installation. When hydrogen and oxygen are separated to make fertilizer, it's easy to accumulate heavy hydrogen. The heavy water was built up from that.

It was a fateful decision . . . : Academic families in pre-1945 Germany were often among the most nationalistic, identifying easily with the militarily-proud Berlin government. Many of these families saw Germany's rise as dependent on such "heroic" moves as the attacks on Denmark and Austria in the 1860s and on France in 1870, and the invasion of Belgium in 1914.

When those expansions collapsed in 1918 the feeling of being trapped simply got stronger. There were constant reminders: When Heisenberg was dominating the world's physics establishment with his 1920s work in quantum mechanics, French occupation troops—often of the lowest quality—were still on his nation's soil. The result was a querulous, resentful tone in much of the country's elite— and so a burst of satisfaction, when finally, in the first successful years from 1936 on, the long-delayed expansion could begin again.

"democracy can't develop sufficient energy . . .": Cassidy,
Uncertainty,
p. 473; indeed all of Chapter 24 are recommended. See also, e.g., Abraham Pais,
Neils Bohr's Times
(Oxford: Oxford University Press, 1991), p. 483 as well as Walker,
German National Socialism,
pp. 113-115.

"It fell to me . . .": R. V Jones, "Thicker than Water," in
Chemistry and Industry,
August 26,1967, p. 1422.

"Halfway down we sighted our objective . . .": Knut Haukelid,
Skis Against the Atom
(London: William Kimber, 1954; revised 1973, London: Fontana), p. 68.

"Where trees grow, a man can make his way": Ibid., p. 65.

12. America's Turn

[Ernest Lawrence's] personnel skills made Heisenberg look considerate . . . : Which does not mean that Lawrence's managerial style couldn't produce benefits in another fashion. For Lawrence ended up collecting students who prospered in his sort of environment. Many of them stole from each other, or snipped out each other's names from original copies of experimental results, yet the Berkeley lab was never strictly immoral. It was "amoral"— and that's very different. Many of its members simply raced in any way possible to fulfill what the outside world wanted. If prestige in medicine came from finding tools to cure disease, then that's what they would back-stab to achieve.

When E = mc
²
and associated technologies opened up a range of new opportunities, Lawrence's squabbling young men became some of the main controllers of the "spigot" carrying those new powers into our world. They supplied the improved medical tracers to de Hevesy and his colleagues; they worked on improved devices for practical X-ray focusing, for radiotherapy in cancer, and much else. After the war the atomic bomb project opened a gushing well—of grants, contacts; technical knowledge—and Lawrence's men simply happened to be very experienced at pressing to the front of whatever well they saw. An entire book could be written on the interplay between the ethical and practical issues involved.

America's own physics establishment had been so weak . . . : But this was changing fast. For the way returning postdoctoral fellows seeded prime universities in the U.S., see Daniel J. Kevles,
The Physicists: The History of a Scientific Community in Modern America
(Cambridge, Mass.: Harvard University Press, 1995); especially Chapter 14.

"In July 1939, Lawrence . . .": Emilio Segre,
A Mind Always in Motion
(Berkeley: University of California Press, 1994), pp. 147-48.

. . . factories thousands of feet long . . . able to filter toxic uranium clouds: And this—not the space program—is where Teflon got its first commercial use. The pumps controlling the Tennessee factory filters needed sealants that would be immune to the highly reactive vapor. Substances where fluorine atoms wrap protectively around carbon chains are ideal; the resultant polytetrafluoroethylene is what later became shortened to
Teflon.
Eventually it was realized that a substance that toxic uranium clouds weren't going to stick to would have little problem with the frying pan residues of ordinary suburban kitchens. When the same polytetrafluoroethylene is stretched to form a membrane, Goretex is the result.

"He said he appeared not to believe in the eventual success . . .": Peter Goodchild, /.
Robert Oppenheimer: Shat-terer of Worlds
(New York: Fromm, 1985), p. 80.

"It won't be any trouble . . .": Alice Kimball Smith's 1976 interview with Nedelsky, in
Robert Oppenheimer: Letters and Recollections,
ed. A. K. Smith and Charles Weiner, (Palo Alto: Stanford University Press, 1995), p. 149.

One team . . . was simply trying to pull out the most explosive component of natural uranium: This is the famous U
₂₃₅
, which forms a bit under 1 percent of ordinary uranium, whose main ores are the calmer U
₂₃₈
. One way to remember the difference is that you can hold 50 pounds of U
₂₃₈
in your cupped hands, and only feel a slight warmth, but if you ever found two separate 25-pound chunks of U
₂₃₅
and decided to bring them together, the best details your next of kin could hope to get would have to be supplied by CNN helicopter-borne camera crews, using extreme telephoto lenses to get pictures of the blast site and crater.

A more humdrum way to remember the difference between these two types of uranium is by focusing on the nature of even and odd numbers. Since U
₂₃₈
has 238 particles in its nucleus, everything inside that nucleus is "paired off: an incoming neutron isn't going to have any loose partner to affect easily. But since U
₂₃₅
has an odd number of 235 particles in its nucleus, that means there are 46 pairs of protons and 71 pairs of neutrons—and one extra neutron. That's the vulnerable one. When a fresh neutron arrives from the outer world, it easily reacts with the spare neutron; the result is now 46 tightly bound pairs of protons and 72 tightly bound pairs of neutrons. When a nucleus is configured in this "tighter" way, it's much easier for potentially fissile segments to shoot out. Why that happens— and how it produces a lower energy barrier—is at the heart of practical atomic engineering.

Although . . . there were exceptions . . . : The Du Pont engineers who constructed the setting for the Hanford reactor core knew little of atomic physics, but they did know the basic engineering principle that something's always going to go wrong, and you need to allow extra architectural space for the fixes. When the first full running of the reactor slowed due to xenon building up as a by-product of the reaction, they had left enough extra space—following Wheeler's earlier suggestion—that it was easy to increase the amount of uranium used without tearing apart and rebuilding the reactors. The extra uranium's power more than made up for the xenon. See John Archibald Wheeler,
Geons, Black Holes, and Quantum Foam
(New York: Norton, 1998), pp. 55-59.

. . . a ball of plutonium . . . low-density: The phrase
low-density
is of course relative; it's still far denser than lead. The significant point is that it's not dense enough to self-ignite.

"It stinks!": Nuel Phar Davis,
Lawrence and Oppenheimer
(London: Jonathan Cape, 1969), p. 216.

Teller was vain enough . . . : Teller's private project was the hydrogen bomb, a device far more powerful than what could be built out of uranium. The fact that Oppenheimer later had doubts about its necessity was one of the reasons a petulant Teller testified against Oppenheimer in post-war loyalty hearings.

"All that day Serber amused herself. . . ": Serber,
The Los Alamos Primer
(Berkeley: University of California Press, 1992), p. 32. From the same page: "I remember someone at Los Alamos saying that he could order a bucket of diamonds and it would
go
through Purchasing without a question, whereas if he ordered a typewriter he would need . . . to get a priority number and submit a certificate of need."

"It is possible . . .": Richard Rhodes,
The Making of the Atomic Bomb
(New York: Simon & Schuster, 1986), pp. 511-12. I've added the layout of addressee and date.

Even a few pounds . . . uninhabitable for years: What could Germany have plausibly achieved? Probably not an entire bomb, but a reactor using carbon dioxide as a moderator rather than heavy water had been strongly pushed by Paul Harteck, the physical chemist based in Hamburg. It would have been easy to construct with the uranium supplies and engineering skills Germany had; the large amounts of highly radioactive substance produced would have been simple to mount on a V-i or V-2. Note that Otto Skorzeny seems to have proposed launching a radioactive weapon from a submarine to explode in New York. Coming from ordinary staff planners, that proposal could have been discounted, but Skorzeny was the man who'd organized and led the glider-borne assault that snatched Mussolini from an "impregnable" mountain prison in 1943. Certainly Nazi submarines could easily reach the East Coast of the United States, and occasional ones had been equipped to launch small planes.

Most of all, though, a reason for ongoing caution was the extraordinarily deep engineering and scientific establishment that Germany still had, even in the midst of the war. America avidly employed any chemists with experience in the Clusius process used for separating isotopes, but Germany had Professor Clusius himself—as it also had Professor Heisenberg, Professor Geiger, and the rest. There was a huge middle ground of production engineers, able to pull out such surprises as the factories of jet-powered and rocket-powered aircraft, the extreme long-range submarines, the V-2 rockets, and other devices available before the end of the war. Many of those had problems being produced and deployed in large numbers, but a reactor or even a complete bomb that Heisenberg had managed to finish would only have needed to be deployed once or twice to possibly change the decisions of entire nations.

How close could it have come? In early 1940, Harteck felt he'd need up to 300 kilograms of uranium to test his carbon dioxide idea. He arranged to get the dense frozen carbon dioxide (dry ice) from I. G. Farben; a train car (from army ordnance) to speed it to Hamburg; the necessary uranium from Heisenberg and the Auer company. But at the last moment, Farben declared they could only supply the dry ice until early June; they'd need it after that for keeping food fresh during the hot summer months.

Harteck was frantic, but he could only get the full uranium amounts from Heisenberg in late June. Farben wouldn't budge. Harteck scraped together about 200 kilos of uranium, but with that low amount his results were inconclusive; Germany did not go ahead with the easy, dry
ice
reactor that (later experience shows) would almost certainly have given them plenty of radioactive metal early on in the war. Thus was the clear hot weather of that summer— so often cursed by the Allies for letting Panzer armies advance into France—central to forestalling this greater evil. Mark Walker,
German National Socialism and the quest for nuclear power 1939-1949
(Cambridge: Cambridge University Press, 1989), p. 25 passim has Harteck's efforts; see also Bernstein,
Hitler's Uranium Club.

. . . Eisenhower accepted Geiger counters . . . : Groves met with General Marshall on May 23,1944 and explained that "Radioactive materials . . . are known to the Germans; can be produced by them and could be employed as a military weapon. These materials could be used without prior warning in combating an Allied invasion of the Western European Coast." The meeting led to portable Geiger counters being produced and a mission to Eisenhower explaining their use. Directives soon went out from Eisenhower's England-based staff that any invasion force officers finding strangely fogged X-ray film were to immediately report this to GHQ, and similarly any units that experienced a strange new epidemic disease
aof
unknown etiology" having symptoms of hair loss and nausea. See Leslie Groves,
Now It Can Be Told: The Story of the Manhattan Project
(London: Andre Deutsch, 1963), pp. 200-203.

George de Hevesy had dissolved [the Nobel gold medals] . . . : George de Hevesy,
Adventures in Radioisotope Research
(London: Pergamon, 1962), p. 27

. . . no German divers could bring it up from the lake's depths: The American Great Lakes are fairly shallow dips in the ground, where glaciers scraped away the surface, but Tinnsjo is a sheer mountain valley over 1,000 feet deep that has filled with water. It's one of the deepest lakes in Europe.

Norway command to London: The radio messages were recalled from memory, in Haukelid's
Skis Against the Atom,
p. 126. I've changed the heading from "Hardanger command" to "Norway command," and added "stop" between sentences (as Haukelid did for an earlier message on p. 78). The Hardanger plateau was the region where the men were operating.

"When I left the watchman . . .": Haukelid,
Skis Against the Atom,
p. 132.

The equipment lugged from Berlin . . .": For the cave's siting: Boris Pash,
The Alsos Mission
(New York: Award Books, 1969), p. 206ff; also David Cassidy,
Uncertainty: The Life and Science of Werner Heisenberg
(Freeman, 1992), p. 494. For waiting till dawn on Heligoland: Werner Heisenberg,
Physics and Beyond: Encounters and Conversations
(London: George Allen & Unwin, 1971), p. 61.

. . . the German researchers had reached about half the rate . . . : They'd achieved a neutron multiplication rate of nearly 700 percent (in Heisenberg's recollection). About twice as much—requiring more uranium and more heavy water—would have been needed for a sustained reaction. See Cassidy,
Uncertainty,
p. 610.