In “Copenhagen” Michael Frayn achieves the impossible; he makes physics fascinating to the non-scientist.  Frayn does this by creating dramatic tension between Danish atomic physicist Niels Bohr and his former star pupil, German scientist Werner Heisenberg as they meet again, after a number of years, in  Nazi-occupied Copenhagen during World War II.  Heisenberg, after a father-son relationship with Bohr, had written as the war began in 1939, thanking Bohr and ending the friendship.   History knows that Heisenberg visited Bohr in 1941, when both the Germans and the allies were working on the atom bomb, but no one knows what was discussed. The play dramatizes what might have happened at the meeting, giving the audience different versions from which to choose.

Frayn’s mind-gripping drama asks, but never answers, many questions: How responsible were the scientists for their equations used to created the atomic bomb and its mass destruction of Hiroshima as well as its threat of annihilation of the world?  Did they consider at the time the moral implications or only the political ones of winning the war?  How much did the Nazis know about the atomic bomb and how close were they to producing one of their own?   Was Heisenberg sent by the Nazis to visit Bohr and pry out of him the last equation needed by them to make their own bomb?

Time is flexible as the play moves back and forth in time. It opens in the present, with the characters dead and looking back to the meeting, which then ensues. Dead, Heisenberg after the bomb has been dropped, is able to arrive at equations that he says evaded him during the war. Might some moral compunction have contributed to his earlier delay in progressing towards the necessary equation?

Under Michael Blakemore's direction, the action is never static because the conflict between the two men is sustained throughout, conflict which is not physical but intellectual.  Expertly enacted by William Brand as the German, David Baron as the Dane, and Corinna Marlowe as his wife Margarethe, they achieve the necessary excitement to keep the audience intrigued -- even though we know the outcome: the Nazis did not get the bomb  (their persecution of the Jews led to Einstein's flight to America) and it was created and dropped by the U.S., winning the war and assuming the guilt. When the scientists agree to use “plain talk” for Margarethe’s benefit, her comments and questions clarify scientific principles for the audience. Thus we leave the theater feeling not only cleverer than when we entered, but also exhilarated by the give-and-take of the arguments as they in turn enlisted our rejection and our sympathy.

On an almost bare stage in the shape of a circle with three chairs, the action moves freely from indoors to outdoors and the famous walk that we know the two engaged in while discussing and disagreeing. For this the circle is perfect, just as it is a metaphor for the arguments for and against the bomb, which over the past half-century have, like a circle, been endless.          

Some historians believe that Heisenberg paid his visit to find out how far along the allies were with developing the bomb; others believe that he was attempting to find out information from Bohr that would allow the Germans to progress with their own creation of the atom bomb on which they were working.  (Bohr later would be one the physicists working in Los Alamos, New Mexico, where the bomb was successfully developed).

Throughout, Mr. Frayn never loses sight of the human element – the emotions involved over the loss of the Bohrs’ son, or the destruction of the men’s long friendship, or Margarethe’s protectiveness of her husband. Personal feelings common to all are finely balanced with scientific arguments that have moral and philosophical implications.  The             “uncertainty principle,” discovered by Heisenberg when young, gives rise to different versions of what happened that night. The playwright notes that the play’s psychological uncertainty is parallel to the uncertainty theory that we can never know everything about an object or an event: “Can we have absolute knowledge of anyone’s intentions?”         

(Duchess Theatre, Catherine Street. London W2)

Note: “Copenhagen” opened in New York the following season, with Philip Bosco as Bohr, Michael Crumpsty as Heisenberg, and Blair Brown as Margarethe.  There is a BBC television version, shown on PBS, with Stephen Rea as Bohr, Daniel Craig as Heisenberg, and Francesca Annis as Margarethe, adapted and directed by Howard Davies.