Michael Frayn

Or when she was writing about Jane Austen, we walked around a lot of Hampshire together.

And she came to Copenhagen with me and I was writing there.

the play called Copenhagen.

And somehow it's sort of osmosis.

It sucks into your bones somehow, the way somebody else works.

Well, what set that off?

I was reading a book by the American writer Thomas Powers called Heisenberg's War.

It was the first time I'd read anything about that meeting in 1941 in Copenhagen.

I have to say that I'm not in any way a scientist, but I did study philosophy.

And if you study philosophy, you can't help but come across quantum mechanics because its philosophical implications are so weird.

So I knew something about what Heisenberg and Bohr had been up to in the 1920s and 30s.

And then reading about the visit that Heisenberg made to Bohr in 1941 during the war, and the difficulty of knowing why he did it, in spite of the fact that Germany had occupied Denmark...

It was going to be very embarrassing for a war to receive a visit from a German citizen who persisted in doing it.

What was it he wanted to say?

And there seemed to me to be a certain parallel between the uncertainty that Heisenberg had introduced into Germany

He was known for the uncertainty principle.

The uncertainty principle, much disputed by a lot of physicists now, but if it's right to suggest we can never have complete knowledge of the physical world.

And what seems to me the case, that we can never have complete knowledge of people's thinking and intentions, even perhaps of one's own thinking and intentions.

Fission?

Well, I had to do a lot of research.