Work Text:
Department of Physics
Universitat Leipzig
Linnestrasse 5
Leipzig
Germany
December 18th 1941
My dearest Bohr,
So again I set pen to paper, and again I pause. 500 miles I travelled, to tell you this story, and I could not manage it then. What makes me think I can do so now, alone in my room, without your comforting presence by my side spurring me on to explanations and deeper understanding? Still, it looks as though that comfort will never come again, and I must learn to write into the silence. The story must be told, and who could understand its implications but you?
You always joked I did my best work in a hurry, leaving others to sort out the detail. So I will leap into the meat of the matter, and leave the social niceties (how is Margrethe? Much love to the children. I hope things in Denmark are not too difficult...) for another day. We were never very good at them anyway, and after our meeting in September they have only become harder. No, instead I will go straight to the strange events of last August, which I longed so much to tell you when last we met.
I was travelling back to Leipzig from Berlin. It was one of those late Summer's days, where the world is heavy and ponderous with heat, and the German Army, in their wisdom, had decided to transport me and my equipment by plane. The nominal excuse was that there would be less risk of damage to the equipment that way, but it was all to be recalibrated back at Leipzig, and it seemed clear to me that this was mostly a propaganda exercise – the wonders of German engineering transporting the wonders of German physics! - and probably a training run for some officer who had not clocked up enough flying hours. Still, it was a break from routine, and I must admit to a certain sense of excitement at the impending journey. One which was to be more than fulfilled...
I was surprised to see the officer waiting at the plane clad in black and silver. It is not, after all, a uniform one expects to see on flight duty, and indeed it is a uniform best respected from a distance in Germany. I straightened instinctively, and assumed my most deferential manner. Yes, Bohr, I can hear you laughing in my head at that – your feisty Werner, deferential to anyone! But these are strange times, and we do what we must to survive.
The officer stubbed out his cigarette, and gestured to the cargo hold of the Tante Ju. I walked over to inspect the storage, and as I turned round to confirm all was fine I saw them. In a flurry of hooves and a swirl of chiffon they came racing across the runway, two beautiful proud women astride fine blooded mares. They were dressed as though for a ball, or some grand state occasion of a hundred years ago, but they rode as though they were born in the saddle, with a grace and a power I have not seen since. They pounded down towards the plane as though they would leap clean over it, and at the last moment pulled their mounts to a halt on a sixpence, laughing, their eyes sparkling.
I can imagine you are no longer laughing, my dear Bohr. You have pursed your lips, and your eyes are quizzical. You are sceptical – and you are not even pondering if my story is real or not, you are debating whether I am aware of my delusions, and you are the victim of an elaborate practical joke, or whether that hot August sun and the pressures of wartime have finally unhinged my mind. The latter is an option I have considered many times. All I can say is that if it were a hallucination, it was one that left me in full possession of my facilities, and one that felt as real to me as the paper and pen I use to write this.
The guard had turned towards the women, and raised a hand in greeting. They slid down from the horses, leaving the reins dangling, and moved towards him. The taller woman wore black, with a silver girdle, and her long black hair flowed silken smooth down her back. She hesitated, as though overcome with some fear or sorrow that she would not speak of. But the other woman showed no fear or uncertainty. She walked towards the plane with a smooth power, her green eyes flashing and her smouldering red hair tousled with the wind, until she was only inches from the guard, looking up at him imperiously.
"My ladies. Has fifty years passed so soon?" This was accompanied by a well practised bow, bringing his eyes down to gaze levelly into hers.
"Indeed, Sir Corey. Will you dine with us tonight?"
"I would be honoured, lady Fiona. The swift passing of the years was never soon enough." Was there a note of reproach in his voice, of one who has been bored of waiting? If so, it was mostly covered by his subservience. I stood by the plane, not wanting to be noticed, unable to take my eyes off the surreal pantomime unfolding in front of me. But the second woman had observed me.
"Sir Corey, who is this?" I heard him start to explain that he had taken work in war again, to pass the years, and I was to be his passenger, but by then Fiona had walked round to where I was standing. She fixed me with a clear gaze that seemed to strip me to my very soul, and then gave me a lowered-eyelash smile that for a second burnt my fears away. "I think, Deirdre, we will take him with us. It would be good to have someone to keep an eye on the horses."
Perhaps a saner man would have turned and run from his delusions, but I had been spell bound by that smile. So I found myself in the cargo hold of the Junker with two remarkably placid horses, gazing out the window as the world fell away. And at that point I wished I had been that saner man, for the things I saw... oh Bohr, there is no way to express the things I saw. The world shifted beneath us, and we raced through a thousand shadows of possibilities. I saw Berlin below us, and as we flew on it became a desolate wasteland, flattened as though by a celestial hammer. Another turn, and the city erupted into flame. The sky flickered through the spectrum, black blazing to red, red draining to green, but on each cycle returning to a dark royal blue, and lingering there for longer and longer. The tortured earth below turned to rich green, and a great forest wilder and wider than any we have walked through in our rambles stretched out from horizon to horizon. Finally, the sky settled, and the plane at last landed on a strip of grass, between the forest and the sea, where a cluster of buildings nestled.
My strange companions walked in to the main hall, and I led the horses to the stables before following them. The hall was small, and laid for an intimate dinner party for three. There were candles on the table, and a fire in the hearth. They were eating and conversing freely, like long separated friends, and the candlelight made the trimming on Sir Corey's dark uniform glitter and shine silver. I stood awkwardly, unsure of where I was or what to do, when I noticed off to one side an instrument, like and yet unlike a piano. I distracted myself investigating the mechanism, and once I thought I had understood it – for it was like none I had ever seen on Earth, and my best efforts to find a similar instrument have failed since returning – I could not resist the temptation to play.
I let myself slide into the familiar patterns of the Beethoven G Major. I heard a murmur from the table – Deirdre asking Corey if something was one of his, and him replying in the affirmative – and then I lost myself in the music, hiding from this dazzlingly strange and unfamiliar world in the comfort of the notes. I remembered the times I had played for you, how you would sit silently by the piano, and I would feel you so near, but be unable to turn my concentration away from the music until it was finished, and you had slipped back across the room away from me. And I remembered the night I first met Elisabeth, playing the same piece, how I had thrown myself into the presto and at the end looked up and met her eyes...
I reached the end, and looked up, into Fiona's sparkling and frank gaze. I blushed instinctively. She turned her head quizzically, and I found my cheeks colouring more. "I hope I did not spoil your dinner," I stammered.
"I had not heard that piece for quite some time. It was perfectly fitting." She smiled. "Perhaps I bought you here so you would play it for us, and you have surpassed my expectations. Now, how should we pay our pianist?"
"A return journey would be rich payment for me, my lady"
"That will be arranged. But my sister and her... her friend Corey will be catching up for quite some time yet. There must be something we can talk about to while away the hours..."
We walked out of the hall, and down on to the beach. The evening was warm, and she was barefoot beneath her gown, leaving my chin level with the top of her head. She asked me about my work, and we gently duelled ideas around the nature of the atom, like well trained fencers enjoying the exercise but pulling any mortal blows. If I had not already been lost in astonishment I would have wondered who she was, to talk so naturally and comfortably on a starlit beach about the mysteries of the universe, that only a handful of our finest physicists even begin to comprehend. But I found myself drawn further and further into the conversation, my ideas rushing away with me. Like the old days, Bohr, like us, walking and talking our way around Europe, each step leading us closer to understanding. Until finally I worked my way round to asking her where this was, and how we had come to be here...
And now I come to write this, my great revelation, and I wonder if I should have told things differently. Perhaps I should have said 'it came to me in a dream', or 'it is obvious from the mathematics'. Perhaps then you would take my idea more seriously. But I would not deny the memory of that summer's night, gazing up at the stars as the waves lapped round our ankles and finally I began to understand what she was telling me. You see, we wrestled for so long with the Copenhagen Interpretation, you and I, with the idea that by observing something we could change the universe. What physics is it, that puts mankind and his measurements back in the centre of all things? And what of Schrödinger and his ridiculous cat? Walking on that beach, she explained it all to me. We do not change the universe, any more than we would cause Elsinore to vanish by deciding to holiday in Tisvilde. We walk a different route, Elsinore is still there, even though we never see it. We may look on at the corpse of a cat, but only a whisper of a shadow away the cat still lives, the atom never decays. We do not change our world – we live in a multitude of universes, and where we think we have changed them irrevocably all we have done is steer a different path through them. All outcomes wait for us, somewhere. And at the heart of all of this are beings who can move along the axis of the universes as easily as we can walk along the beach. They turn a corner, and choices are made and unmade. One step, and we are victorious in the war, another, and our city lies in ashes.
I can imagine the expression on your face, your eyes widening at these ravings of a madman. But I can also imagine that for all you want to dismiss this out of hand, some bit of your brain will start to think on it, and it will not be able to let go. For you of all people will see as clearly as I the paradoxes and the contradictions in our current thinking that this model of reality removes immediately.
The repercussions sound far further than just our physics, Bohr. They get to the heart of deepest philosophy. Do I betray my country if I do not produce a bomb for them? Do I betray mankind if I do? I have wrestled with these questions for so many nights. But now I am free once more. For I fully believe there is a world out there where Heisenberg was loyal to Germany and won the war with his bomb, and I fully believe there is a world where the allies destroyed us utterly. I do not have to decide which world to create and which to destroy. All I do is choose which way this Heisenberg wishes to walk, and there is no more weight to my decisions than which scenery I would prefer to see while I am on holiday. It will all happen. I cannot change that, for it is spun into the physics of the universe. But I can chose which routes to watch unfurl.
And all this was laid out to me, on a starry beach, by a beautiful red haired woman. I asked her why she was telling me, but all she did was smile and say that I reminded her of a brother of hers who she was fond of. And then she drew me to her in a way that was most unsisterly, and I was as lost in her as a man drowning in the deep currents of the sea...
Well, I will not send you this letter. I have caused enough hurt between us by failing to explain once already. It is bad enough that you believe I am arming a crazed Fuhrer with nuclear weapons, I do not need you to believe I am hallucinating entire universes as well. Besides, I think the only person it would explain the mysteries of the universe to would be the censor, and he would not be best placed to appreciate it. I will finish the tale, and leave it in my safe, and only occasionally dream of the world where it is delivered.
We ate breakfast with Deirdre and Corey in the Great Hall the next day. Fiona leaned back from the table. "Did you have a pleasant evening?" she asked with a smile.
Corey looked her straight in the eye. "Why, yes, my lady. As it would appear did you. Let us not wait 50 years for the next one."
"Well, that is in Fiona's hands," replied Deirdre. "She is, after all, the one with the great talent for locating people."
"Oh, but Deirdre," Fiona replied, "I do it for such a reasonable price." She reached out her hand and covered Deirdre's in the briefest of squeezes. Deirdre flushed suddenly. "I do believe you quite enjoy paying it."
After that, it was not too long before we were soaring back through the shifting hellworlds, lightning and fire running the length of the plane as the sky kaleidoscoped around us and the ground buckled beneath us. My own Berlin came into focus once more, and I found myself standing by the plane on the runway where we had first met, watching Fiona and Deirdre leave in a swirl of silk and hoof-beats as sudden as their arrival. Sir Corey, or Officer Corey, or whoever he was bowed briefly at their retreating backs, and once they had vanished out of sight looked over to me. "We'd better get this gear loaded" was all he said to me for the entire journey back. We arrived on time, which given all that had happened threw me slightly. I seem to have spent the rest of this year slightly confused about what month it is. Time must move differently in different places.
The Junker vanished away, a tiny dot in the bright blue sky, taking with it my final link to all that had happened. I think I went a little crazy for the rest of that month. I had seen it all, Bohr, shining and laid out in front of me, and how could I return from that to working on the devilish detail of another device for killing people? I would walk, and mutter to myself, and turn the possibilities and repercussions of the multiple universes over and over in my head, until I thought I would go mad if I did not explain it all to someone. So I came to Copenhagen.
I'm sorry, for all I said there. I'm sorry you leapt to the wrong conclusions. I'm sorry I was so busy being scared of what I wanted to say that I didn't pay enough attention to what I was saying, until it was too late and I had closed off all possibilities of talking to you about what was on my mind.
But I know there is a world out there where we walked and talked in Copenhagen, and I explained it all to you, and we went on to explore the mysteries of the multiverse together. And I know there is another world, where a younger Heisenberg plays the piano, and a younger Bohr does not slip away back across the room but waits nearby to the end of the presto...
My dearest Bohr. I remain, yours,
Werner Heisenberg.