The play mentioned below was really excellent.
February 7, 2002
New Twist on Physicist's Role in Nazi Bomb
By JAMES GLANZ
The leader of Hitler's atomic bomb program, Werner Heisenberg, portrayed himself after World War II as a kind of scientific resistance hero who sabotaged Hitler's efforts to build a nuclear weapon.
But in a series of letters and other documents made public yesterday, his friend and onetime mentor, the Danish physicist Niels Bohr, said that is not so.
Bohr, who died 40 years ago, said that under his beloved protégé, "everything was being done in Germany to develop atomic weapons."
In particular, the documents describe a meeting that Heisenberg initiated between the two men in occupied Denmark in September 1941.
After the war, Heisenberg said he traveled to Copenhagen to share his qualms about nuclear weapons. But the papers, released by the Bohr family and posted on the Niels Bohr Web site, www.nba.nbi.dk, which is maintained by the Niels Bohr Archive, tell a different story.
Heisenberg did not travel to Copenhagen for the 1941 meeting to express moral qualms about building an atomic weapon in wartime or to suggest that physicists on both sides of the conflict should refuse to do so, according to a passage in a letter Bohr wrote to Heisenberg, but never sent.
He was moved to write his letter, the authenticity of which seems beyond doubt, in 1957 when he read "Brighter Than a Thousand Suns," a history of the atomic bomb, in which Heisenberg is quoted offering his defense of his wartime role.
"You said that there was no need to talk about details," Bohr said, "since you were completely familiar with them and had spent the past two years working more or less exclusively on such preparations."
Though historians and scientists agree that Bohr broke off the meeting in shock, they have debated for decades what actually happened that day. Did Heisenberg hope to save the world from the horrors of the bomb, or was he really trying to pry loose information on the parallel effort by the Allies, which Bohr later joined?
The mystery is the center of an award-winning play, "Copenhagen," by the British playwright Michael Frayn. The play was inspired by a 1993 book by the journalist Thomas Powers, "Heisenberg's War," which argues that Heisenberg destroyed the German project from within.
The revelation made public yesterday "pretty much knocks that out of the water," said Dr. David C. Cassidy, a historian of science at Hofstra University who is the author of "Uncertainty: The Life and Science of Werner Heisenberg." "Heisenberg was working full blast on getting as far as he could on nuclear fission, including a bomb."
But others say questions about the meeting remain. One of Heisenberg's sons, Dr. Jochen Heisenberg, who is now a physicist at the University of New Hampshire, and Mr. Powers, say the documents show that Bohr never understood the message Heisenberg meant to convey in Copenhagen.
Even Dr. Hans Bethe, the Nobel laureate who is one of the last surviving physicists of the Manhattan Project, said yesterday he believed that technical misunderstandings between the physicists on what was then the cutting edge of science caused them to talk straight past each other.
"Bohr's letter does not clarify anything about the visit," Dr. Bethe said. "One talked with one set of assumptions and the other with a totally different set of assumptions."
But theirs is a minority view among historians of science. "It is in some way appropriate that Frayn's play was initiated by his reading of Thomas Powers's book," said Dr. Gerald Holton, an emeritus professor of physics and of history of science at Harvard. "It is clear that both of them, now that we know Bohr's report, are essentially fiction."
The history of the documents and the physicists they involve is nearly as interesting as the subject matter they contain.
The two men met when Bohr gave a talk in Göttingen, Germany, in 1922, by which time he was already known as the major theorist of the atom. "Suddenly, up jumps a cheeky pup and tells me that my mathematics is wrong," the character Bohr recalls in Mr. Frayn's play.
It was a 20-year-old Heisenberg, asking critical questions from the audience. Bohr approached him afterward, took him on as a protégé and together, they all but revolutionized physics in the 1920's, playing a central role in the development of quantum mechanics, the science of the very small.
But after their encounter in Copenhagen, Bohr broke off nearly all contact with his former protégé. He escaped from occupied Denmark in 1943 and made his way to England and then to Los Alamos, N.M.
No one knows why Bohr never sent the letter that was made public yesterday. Perhaps the usually soft-spoken Bohr regretted its strong language. But in characteristic fashion, he dictated further drafts and notes on the subject five years later. They appear in the handwriting of his wife, Margrethe, of various assistants and of his son Aage Bohr, another Nobel laureate. (In the play, the character Margrethe complains lovingly about the endless drafts she types for her husband, a deep thinker who was known to revise physics papers as many as 100 times before publishing them.)
Dr. Finn Aaserud, director of the Niels Bohr Archive in Copenhagen, said yesterday that the handwriting of all three had been identified as authentic, leaving little doubt that the documents are genuine.
In an interview, Mr. Powers said he wished Bohr had sent the letter to Heisenberg, so that the German physicist could have responded to its charges. "My overwhelming impression was one of sadness that they had never been sent," Mr. Powers said.
Bohr died in 1962, and during a conference on his work in Copenhagen in 1985, Erik Bohr, another of Bohr's sons, approached Dr. Holton and two others ‹ the physicist Dr. Abraham Pais and the presidential adviser McGeorge Bundy, both now dead ‹ with the first letter, asking for advice on what should be done with it.
Dr. Holton, who until now has been under a pledge of secrecy regarding the contents of the letter, said all three strongly recommended that the letter be preserved. The family agreed, but because of the nature of the contents, decided that none of the documents on the meeting would be released until 2012, 50 years after Bohr's death.
But in a talk during a conference on Mr. Frayn's play at the Graduate Center of the City University of New York in March 2000, Dr. Holton revealed that the letter existed. And with the play ‹ a hit in London and New York ‹ interest in the letter mounted, said Dr. Vilhelm A. Bohr, a grandson of Niels Bohr, and a molecular biologist at the National Institutes of Health in Baltimore.
"There was such an active debate about it and we didn't want to hold up anything that could be of interest to the historians," Dr. Bohr said. "There's nothing that we need to hide here."
Despite the apparent clarity of the recollections in the letters, said Dr. Jochen Heisenberg, Bohr may have been confused by the militaristic, pro-German statements he assumes his grandfather was required to make in public.
In the letters, Dr. Heisenberg said, Bohr does not distinguish "between what my father said in official places and what he said in private." Perhaps Bohr became so angered by those public statements that he did not listen clearly when the two men spoke privately, Dr. Heisenberg said.
Although Dr. Vilhelm Bohr takes exception to Mr. Frayn's portrayal of his own grandparents in certain respects ‹ he said that his grandmother Margrethe was not nearly so outspoken as she is drawn ‹ he still likes the physics-saturated play. And he said the newly released documents would do nothing to change that.
"I still the think the show is very well done," Dr. Bohr said. "People come away very challenged."
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All the thoughts of a turtle are turtle.
Emerson, Journals, 1855
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