Copenhagen . Playwright Michael Frayn

New York Opening

When the play opened in New York it aroused much more controversy than it had in London.

There were a number of American scientists and historians of science who think I have been too soft on Heisenberg, although he is bitterly attacked by Margrethe in the play.

Heisenberg is allowed to make his own case to try and argue out why he did what he did, not only in the meeting in Copenhagen with Bohr, but also during the war in serving German science.

Bohr's Position

Niels Bohr never commented publicly on the meeting in his lifetime. He only told one or two family members and colleagues what he thought had happened at the 1941 meeting. He didn't say anything more about it until after the war when Heisenberg tried to establish with Bohr what had occurred.

Heisenberg was very eager to have some agreed version of the meeting established. But they couldn't agree, so they abandoned the idea.

Heisenberg's Version

Neither of them said anything more about it until some point in the 1950's, when Robert Jungk wrote a book exculpating the German scientists, suggesting that they had tried to run some kind of resistance movement to Hitler.

Heisenberg gave Jungk his version of the 1941 meeting, which appeared in the book. When Niels Bohr read Heisenberg's account he was very angry. He thought that Heisenberg had completely misstated what had happened.

The Bohr Letter

Bohr wrote a letter to Heisenberg, but characteristically he didn't send it. He went on redrafting it, just as he had always redrafted his scientific papers. In fact he went on redrafting it for the rest of his life.

What he was trying to do -- also very characteristic of Bohr -- was to be very precise about what had happened in the meeting as he recalled it. I also think he was trying to find some way of disagreeing with Heisenberg, without hurting Heisenberg's feelings.

The letter was found after his death among his papers.