and Otto Frisch went for a walk by the sea. There was snow on the ground: would this have reminded them of that very first Christmas years ago? Lise Meitner told Otto Frisch of the results of the experiments in Berlin: of the uranium nucleus that seemed to transmute itself into much lighter parts. They knew, of course, that if this were true (what a miracle!) — if the uranium nucleus were split into anything like two — then these parts, being of the same electrical charge, would repel each other with enormous force: then indeed there would be released energy locked up in the heart of an atom — a force for terrible creation or destruction. Lise Meitner and Otto Frisch sat down in the snow: by the waters of a cold grey Babylon they — what? — held pencils and pieces of paper on their knees; they worked on the mathematics. The mathematics for once
— perhaps it was the cold; perhaps it was the urgency of being in exile — did not seem too difficult. The internal charges within the unstable nucleus of an uranium atom were such that it was likely on its own to be on the point of overcoming the surface tension that held it together anyway: for it to split into two might after all indeed take no more than the impact of a neutron. And then — if the nucleus of a uranium atom did in fact split into the two much lighter nuclei of a barium and a krypton atom, which was what Otto Hahn was suggesting — then indeed there would be the violent repulsion and the release of force. But still — where was it, as it were, that the energy for this force came from? For in mathematics something does not come out of nothing. Then it was worked out
— since the sum of the weights of barium and krypton nuclei are slightly less than the weight of a single uranium nucleus, some mass must have been lost in the process; and so what could have happened to this mass except that it must have been transformed into energy? The formula by which mass was transformed into energy was known. Lise Meitner and Otto Frisch sat with their pencils and bits of paper on their knees. And so, yes — abracadabra! — it was seen that the mass that had been lost in the fission process was, when transformed, almost precisely the amount of energy which would be involved in the two new nuclei repelling each other with enormous force; and it was indeed exactly the amount of energy (though this was not seen till slightly later) — if it could be supposed that as part of the explosion were emitted also two or three loose neutrons — which, if suitably controlled, might then, of course, be used for the exploding of further uranium nuclei — and so on — in geometrical progression or chain reaction to whatever strength of
explosion might be required. And what sort of explosion might be imagined to be required — for creation or destruction — by two such exiles in a strange country on a cold Christmas Eve?
You said That is a good story.' Then — 'Yes, it should be true.'
I said 'It is not all that far from what I imagined in Spain.'
Donald Hodge said 'The day after Christmas, Otto Frisch travelled to Copenhagen to see Niels Bohr. And Niels Bohr said "But what fools we have been, not to have seen this before!"'
I said 'Oh but how would it have been proper for us to have seen it before!'
You said 'How long will it take?'
Donald said 'It will take time to handle, if indeed it can be handled at all — time, and a great deal of money, and work, and imagination.'
I said 'Then that's all right.'
Donald said 'What is?'
I said 'I think imagination is on our side.'
Donald said 'And, with luck, money.'
You said 'But time?'
It was not long after this that Hitler marched into what was left of Czechoslovakia; then began to make threatening noises against Poland. I thought — It is obvious what is in runaway: what else but a coincidence like this might be imagined to be in control!
I said 'We always knew that there was something urgent to be done.'
You said 'I don't think this makes it easier to separate from each other.'
In the summer, you set off for Zurich: to find what news you could about your father; to try to make contact with Franz, to find out what was happening in Germany about a Bomb; perhaps to pursue the course of study that you had embarked on years ago — the one concerning the connections between coincidence, the workings of the imagination, and fact.
I said 'You will be careful.'
You said 'And write to me every day.'
I said 'Meet you on top of the gasworks, twenty minutes.'
Ascona this year is on The Symbolism of Rebirth in the Religions of All Times and Places'.
These metaphors! They remind us that language is no more than a shot at reality.
— In reality, am I in touch with you?
I have been told of an experiment in which you take a mother and a child cat, separate them, then if you kill the child cat, for instance in Australia, the mother cat, in Europe, attached to suitable recording instruments, will show signs of instantaneous distress.
I am sad. I am lonely.
You are happy?
I sit on a jetty and look out across the lake. I imagine rising up out of the water a hand with a sword with a message on it -
— You call this reality?
There is no more news from my cousins about my father. He was in Sachsenhausen concentration camp in 1936; he remained there till probably early this year; then he was let out. He is now said to be working for the government.
Why did the Nazis let him out? Does he know what he is doing? Does he expect me to know?
Might we not both be in danger if I, his errant daughter, try to make contact with him?
Practising. Testing.
In the years before 1936 he had become known for his outspokenness in defence of Jews: it was for this, presumably, that he was arrested. He was also becoming known for his work on the philosophical and even political implications of modern science. For this (as well as for the other accomplishment) he had gained the respect of many different kinds of scientists. So the government might well have thought that he could be useful to them in the runup to war; and his wife, my mother, a Jewess, was now dead.
There might be good or bad reasons for his not getting in touch with me. There might be good or bad reasons for my not having got in touch with him. He might be ashamed: or he might be something more rare on this strange planet
He might have some design. He might know that I would know what he is doing. To take responsibility on oneself — to expect others to take responsibility on themselves — this is to go against the dependence on others that is taken to be social responsibility on this sad planet.