She said 'Perhaps we can scoop up some of this light and with it make bullets to use against General von Luttwitz!'
My father would say 'Yes, my dear, one day we might even be able to do something like that.'
This was the time — the winter of 1919-20 — when there were barricades again going up in the streets: when there was apparently the threat of a revolt by right-wing extremists against the moderate socialist government.
I would say, as I so often said — 'But what is it really that is happening?'
My father said 'What was that thing you said the other day?'
I said 'That / said?'
He said 'That just by seeing that we can't get out from our own vision, we might be out.'
I said 'I said that?'
My father used to walk up and down in his study at this time as if he were very excited. I remember an evening when we, he and I, could hear my mother, as usual, banging plates and cutlery about in the dining-room: my father turned to me and said 'We might even go out to your mother and say that we are ready for supper!' He
did this, and my mother looked amazed. I thought — Well, that was brilliant!
During that winter my father struggled to put into words what might make sense at least to himself about what was happening in physics. I think he planned to write some short book or pamphlet on the General Theory, though there were no traces of such a manuscript in what later was found of his papers. There were however some notes in a notebook. What he was trying to do, it seemed, was to say that there were two problems — one was to try to understand Einstein's mathematics, and the other was to try to understand what mathematics in general was doing. These, he said, were problems on different levels. The second problem had, as it were, to look down on the first: what was required was a type of language that could talk both about mathematics, and about what mathematics is.
There was a sentence in his notebooks — 'Reality is not a metaphor we construct from mathematics: mathematics is one of our metaphors for reality.' Also — 'If we try to put knowledge on this level into words, are we not back in the trap of language?'
During this winter (I was now perhaps ten) my father and I continued with our reading from story books and science magazines; these often seemed curiously relevant to what we tried to talk about. There was one story that I remember in particular which was to do with some people who were on a trip to outer space; they were, yes, in an airship. They were led by a man called Captain Steadfast; their second-in-command was a boy called Max. There was even a supposedly mad scientist whose head seemed to be set loosely on his shoulders. Captain Steadfast was on a mission to an outer galaxy where there was an evil demon about to dominate the universe; this was to be done by means of noise; the earth was being bombarded with inaudible but unbearable frequencies of noise; this was sending people mad; they were jumping about, bashing one another, starting wars; they could not tell what was plaguing them. Captain Steadfast and his crew had to find and destroy the evil demon before people on earth destroyed themselves. Also on the demon's star there was a beautiful girl imprisoned who might, if freed, lead Captain Steadfast to the source of the terrible noise. My father would look up every now and then and say 'This really is a very good story!' I identified, of course, with the boy called Max. The climax came (I remember it well!) when Captain Steadfast's airship was approaching the demon's star; the airship came up
against a solid barrier of noise; the evil demon had put out sound waves so that they were like a wall; the airship banged against this wall but could not get through; the airship was breaking up! Captain Steadfast was being defeated. Then someone aboard had the idea (was it the mad Professor? was it Max?) that what had to be done was to create a vacuum in front of the airship — sound cannot travel through a vacuum — so that if the vacuum could be made the airship could get through. So the propellers at the front of the airship were put into reverse; they went faster and faster; the propellers at the back drove the airship forwards; somehow or other the propellers at the front created a vacuum! And so Captain Steadfast and his crew got through. And they destroyed the evil demon and rescued the girl; and people on earth stopped hopping up and down as if they were demented.
My father and I were quite carried away by this. We sat side by side staring at the ceiling.
I said 'But could that sort of thing be true?'
He said 'Well, it is true that sound cannot exist in a vacuum.'
I said 'What about light?'
He said 'Ah yes, light.' Then — 'What we want to do, perhaps, is to make a vacuum in our heads, and then light might break in; and then it might not even have to be us who break through!'
We sat with our arms round each other staring at the universe. Sometimes there did seem to be outlines of dark light around the objects in the room in front; as if we were through to a strange planet.
At night I would lay in bed and would try both to think and to stop thinking of all this: there were all these lumps of light coming down — had it not been proved that light had weight? a hundred and sixty tons of it fell on the earth each day! — so what would become of us? Would we be crushed? Would we be made full of holes like a sieve? Was it true that if one made one's mind a blank then such images might fall through? There would be bits of gold and diamonds at the bottom of the sieve.
Sometimes at night there would be the sounds of my mother's and father's voices across the passage: my mother was nagging at my father; my father was being so reasonable; but it seemed to be his very reasonableness, like the demon's unheard voice, that was sending my mother mad. My mother would shout 'You think I don't know about the beautiful things you talk about with Eleanor!' My father would say indeed I would like you to be interested in
the beautiful things I talk about with Eleanor.' Then occasionally (as almost happened with Captain Steadfast's airship) my father's patience would break; he would roar and rage at my mother. I would want to shout — But the vacuum! The vacuum! Then I would think — Do we each of us have our evil demons and our Captain Steadfasts in our universes? I would try to go to sleep. But how do you make your mind a vacuum in order to go to sleep? I thought — There must be some trick: how does it happen, just when you are not looking, that you get tipped over on to another universe.
Of course, there were a myriad other things going on in my life at this time: there was my work with Miss Henne; the tea-parties at the houses of friends. But it was my relationship with my father that was like a thread through the maze; it was because of this, of course, that I remember it; one does not remember what is random in a maze.
There are two more instances that pick themselves out from the oddities of this time — the thread of memory bumping me into this or that corner of the maze.
The first was to do with the occasion that became known in history as the Kapp Putsch: this occurred in Berlin in March 1920. There had for some time been rumours — coincidental with the excitement over the confirmation of Einstein's General Theory — of a possible coup by right-wing militarists: these were objecting to what they saw as a too easy acceptance of the terms of the Treaty of Versailles. In particular there was said to be danger from General von Liittwitz whose troops did in fact move in from where they had been encamped in the suburbs; members of the socialist government under President Ebert fled to Stuttgart; a new government was proclaimed with at its head a conservative politician called Kapp. But then there was the question — as indeed had occurred before to other revolutionaries — what are troops to do after they have marched into the centre of their own city? There they are with their baggage-wagons and bedrolls and field kitchens; where have they to go, what have they to do, except in the end to march out again?