Copenhagen - Michael Frayn [20]
Bohr And find out how my ideas on spin have developed en route.
Heisenberg Oh, those years! Those amazing years! Those three short years!
Bohr From 1924 to 1927.
Heisenberg From when I arrived in Copenhagen to work with you …
Bohr To when you departed, to take up your chair at Leipzig.
Heisenberg Three years of raw, bracing northern springtime.
Bohr At the end of which we had quantum mechanics, we had uncertainty …
Heisenberg We had complementarity …
Bohr We had the whole Copenhagen Interpretation.
Heisenberg Europe in all its glory again. A new Enlightenment, with Germany back in her rightful place at the heart of it. And who led the way for everyone else?
Margrethe You and Niels.
Heisenberg Well, we did.
Bohr We did.
Margrethe And that’s what you were trying to get back to in 1941?
Heisenberg To something we did in those three years .… Something we said, something we thought .… I keep almost seeing it out of the corner of my eye as we talk! Something about the way we worked. Something about the way we did all those things …
Bohr Together.
Heisenberg Together. Yes, together.
Margrethe No.
Bohr No? What do you mean, no?
Margrethe Not together. You didn’t do any of those things together.
Bohr Yes, we did. Of course we did.
Margrethe No, you didn’t. Every single one of them you did when you were apart. You first worked out quantum mechanics on Heligoland.
Heisenberg Well, it was summer by then. I had my hay fever.
Margrethe And on Heligoland, on your own, on a rocky bare island in the middle of the North Sea, you said there was nothing to distract you …
Heisenberg My head began to clear, and I had this very sharp picture of what atomic physics ought to be like. I suddenly realised that we had to limit it to the measurements we could actually make, to what we could actually observe. We can’t see the electrons inside the atom …
Margrethe Any more than Niels can see the thoughts in your head, or you the thoughts in Niels’s.
Heisenberg All we can see are the effects that the electrons produce, on the light that they reflect …
Bohr But the difficulties you were trying to resolve were the ones we’d explored together, over dinner in the flat, on the beach at Tisvilde.
Heisenberg Of course. But I remember the evening when the mathematics first began to chime with the principle.
Margrethe On Heligoland.
Heisenberg On Heligoland.
Margrethe On your own.
Heisenberg It was terribly laborious—I didn’t understand matrix calculus then … I get so excited I keep making mistakes. But by three in the morning I’ve got it. I seem to be looking through the surface of atomic phenomena into a strangely beautiful interior world. A world of pure mathematical structures. I’m too excited to sleep. I go down to the southern end of the island. There’s a rock jutting out into the sea that I’ve been longing to climb. I get up it in the half-light before the dawn, and lie on top, gazing out to sea.
Margrethe On your own.
Heisenberg On my own. And yes—I was happy.
Margrethe Happier than you were back here with us all in Copenhagen the following winter.
Heisenberg What, with all the Schrödinger nonsense?
Bohr Nonsense? Come, come. Schrödinger’s wave formulation?
Margrethe Yes, suddenly everyone’s turned their backs on your wonderful new matrix mechanics.
Heisenberg No one can understand it.
Margrethe And they can understand Schrödinger’s wave mechanics.
Heisenberg Because they’d learnt it in school! We’re going backwards to classical physics! And when I’m a little cautious about accepting it …
Bohr A little cautious? Not to criticise, but …
Margrethe … You described it as repulsive!
Heisenberg I said the physical implications were repulsive. Schrödinger said my mathematics were repulsive.
Bohr I seem to recall you used the word … well, I won’t repeat it in mixed company.
Heisenberg In private. But by that time people had gone crazy.
Margrethe They thought you were simply jealous.
Heisenberg Someone even suggested some bizarre kind of intellectual