But there will be no explosion yet.
The explosion starts with the addition of TNT, which Joan adds into the diagram by enclosing the circle of uranium inside an outer square of yellow explosive, still contained within the fish’s stomach. She colours this carefully, not allowing any of it to spill into the core as there can be no easy mingling of substances. When the TNT is activated, it will fire the two halves of the core together to create a critical mass. This explosion will be big in itself, but not huge. At this stage it is not astronomical so much as economical. It will work as a highly efficient multiplier of energy.
The astronomy will occur a millisecond later, when the detonation activates the neutron source, which Joan colours in blue, firing neutrons at the critical mass of uranium. This is where the real explosion happens. This is what Max describes in his papers as the genius of the invention: that having found a substance so unstable that it is ready to burst at the smallest nudge, the trillions of nuclei are pressed together into a critical mass and from then on the reaction is uncontrolled and self-sustaining, catastrophic; an enormous, white-hot burst of energy. It is a process of numbers, of chain reactions. It will be so quick that it will appear instantaneous, a sudden explosion of heat and neutrons and light, as if God himself has pulled his knees into his chest, curled up into a ball and flung himself at the earth.
Joan labels the diagram, sketches in the main design features of the tail, and shades the outer casing in grey. She will not think about the possibilities of what she has drawn. She understands the science, or most of it. Her limitations are merely a question of scale.
The Prime Minister arrives promptly at 2 P.M., seated in the passenger seat of a dark green car that sits incongruously on the narrow street outside the laboratory. At first he looks so like the photographs and yet so different that Joan wonders if it is not perhaps an impersonator trying a bit too hard. Surely he doesn’t always have that cigar in his mouth? She observes him shaking hands with Max and Donald and Arthur and still she is not sure. It is only when he takes her hand in his, smiling plumply out of the side of his mouth so that his face seems to flatten and he booms in that particular clipped voice she knows so well from the wireless: ‘Ah, my dear young lady. Who’s a man got to ask to get a decent cup of tea around here?’
Now that, thinks Joan, is either a bloody good impression or it’s really him.
She feels her face grow hot. ‘Milk and sugar?’
He nods slowly, evidently amused by something. ‘I’ve heard that’s how it’s done.’
She leaves the line-up to make tea in the kitchen and finds that her hands are shaking a little. The visiting party progresses through the laboratory and into Max’s office. Joan places the large brown teapot on a tray with some biscuits, sugar and a jug of milk. It is heavy in her arms as she walks slowly along the corridor, pushing the door open with her back and trying to place it on a side table without producing too much of a rattle. She pours the tea and hands it around while Max begins his explanation.
Her diagram is tacked up on the wall behind Max and he is referring to it with a pointer while also gesticulating towards various equations chalked up on the blackboard next to it. Joan’s attention drifts as Max speaks, her eyes drawn to Churchill’s presence in the room, the watch-chain slung across his waistcoat, the deep frown in his forehead.
‘What a curious drawing,’ he interrupts. ‘Is this actually how it’s envisaged to look?’
Max glances apologetically at Joan. ‘I think it’s an extremely good approximation,’ he says. ‘Although simplified, of course.’
‘Harrumph,’ Churchill says approvingly.
Joan flushes. She puts down the plate of biscuits and scrutinises her drawing from across the room. She has seen smaller versions of her fish-shaped drawing dropping from the skies in the past few months. She has seen unexploded ones roped off among the broken-windowed rubble of Cambridge, policemen holding back the crowds as they cluster and crane to see what all the fuss is about, as if a ferocious yet exotic animal has escaped from the zoo. In outline, it’s familiar enough.
Max is holding up a graph, inviting his audience to take a closer look. ‘Initially, it was thought that several tons of uranium 235 would be required to generate any sort of explosion,’ he explains, ‘as these are the sort of figures we’re used to. And that would be almost impossible to generate, given that approximately 99.3 per cent of all natural uranium comes in 238 form.’ He takes a breath. ‘But recent calculations have revised the estimated amount needed quite dramatically. We know now that a significant explosion would require a critical mass of only a few pounds.’ He cups his hands to demonstrate the amount. ‘About the size of a small pineapple.’
Churchill coughs. ‘You do understand what you’re making here, Professor?’
Max stops. He blinks. ‘Yes, sir. Of course I do.’
‘And do you ever wonder how we will be judged by future generations?’
‘I do, sir.’
Churchill sits back in his chair and takes out a box of matches. He removes one, lights it, and then takes a cigar from his pocket, the end of which he holds in the centre of the flame. ‘And do you sleep at night?’
Max gives a half smile. ‘I haven’t slept for years,’ he says.
‘Ah, you’re one of those. I know that feeling well.’ Churchill turns his attention to the cigar, putting it into his mouth and puffing at it until it catches.
Max clears his throat, evidently put out of his stride by the question.
‘I didn’t mean to alarm you,’ Churchill continues in a perfectly enunciated drawl. ‘I’m merely checking that this thing is not being built by a monster. If you told me you slept soundly every night without a moment’s thought for the end product, then I’m afraid I would probably return to London with your letter of resignation in my pocket.’
Max smiles nervously. ‘There are other uses for this research,’ he says. ‘I like to think that it will do some good in the world. After the war.’
Churchill looks at him. ‘Perhaps. I hope so. But for now we must accept that we cannot control how history will judge us, unless we write it ourselves, of course, but we can consider whether we would be judged more for not making this thing than for making it. And I am willing to bank on the former.’
‘I believe the idea is that it exists as a deterrent.’
Churchill nods. ‘Yes, indeed. But a deterrent against whom?’
‘The Germans, naturally.’
A snort this time. ‘For now,’ he says, and his voice is gruff, low, ‘although it’s the Yanks we need to worry about.’
Max frowns. ‘But they’re on our side. We’re working with them on this.’
‘True.’ Churchill takes a deep inhalation from his cigar and then turns to the window to exhale, giving the impression that he is talking to no one in particular. ‘But we’ve got to have one of these buggers over here,’ he continues, and his voice is quiet now, considered, ‘because if we don’t the Yanks will control everything once this is all over. We’ve got to have one, and we’ve got to have the bloody Union Jack on top of it.’
Joan hears this exchange but does not really take it in. She has been looking at the figures on Max’s chalkboard and now she is staring at the picture, her face suddenly ashen. Max rustles his notes, coughs, and resumes his explanation of how, exactly, this invention can transfer such a huge amount of energy from one source to another, and how once it starts it can continue to do this on and on, creating energy at an inhuman speed.
And there it is at last: the hint of metaphor that she can no longer hold back from exploding in her brain; the word that she has pushed back and back and back, not really wanting to think of what it is they are creating here.
Because it’s not just the speed that’s inhuman, is it?
TUESDAY, 4.02 P.M.
Ms. Hart is outside talking to someone on he
r mobile phone, and Mr. Adams has gone to the shops to buy more coffee. The video camera has been switched off during the break. Nick is standing at the window, looking out across the darkening front garden to the road. He is shaking his head, still thrown by this most recent revelation.
‘I can’t believe I never knew,’ he says at last. ‘My own mother, working on the atomic bomb. I’d never have thought . . . ’ He stops. ‘You’ve never even hinted at it. I remember asking what you did during the war and you fobbed me off with your secretary story.’
‘But I was a secretary.’
Nick narrows his eyes at her. ‘Maybe, but not just a secretary, as you told me.’
‘I couldn’t have told you any more than that. It was still classified. I’d signed the Official Secrets Act.’
‘As if that would have mattered by then. The bomb wasn’t exactly a secret once everyone knew about it. I learnt about it in school for God’s sake.’ He stops and turns to look at Joan. ‘And you never told me that you met Winston Churchill. Even when I did that school project on him.’ He gives a sudden burst of incredulous laughter. ‘I mean, who meets Winston Churchill and then never mentions it again?’
Joan leans forward, wanting to reach out to him but retreating when she sees his expression. ‘Nobody said what they did during the war. They were different times.’
‘I know. I’m not angry that you didn’t tell me. It’s just such a shock. You never let on that you ever did anything like that. Not once. I feel as if I don’t know who you are.’
Joan looks at him. Does he not think she could say the same about him, or anyone for that matter? Although of course, she would never say such a thing. And perhaps the comparison isn’t fair. He has always done so well at everything, been so good, that she has worried on occasion that he has done too well. Don’t they say that about adopted children, that they think they need to be perfect to make up for the fact that they were once given away? Nick dismissed this theory as pop psychology the one time she tried to broach it with him. ‘I’m still me, Nick,’ she says softly. ‘I’m still your mum.’
He shakes his head, and Joan sees for the first time that he is hurt. His eyes are unnaturally shiny and he is avoiding her gaze. She feels her heart burn.
‘But you’re not who I thought you were. When anyone asks me what you did, or what you liked, I always said you were a librarian at my school and that you and Dad liked playing tennis, and I thought that was the truth. I thought that was all there was to know.’
‘It is,’ she whispers. ‘Or it was by then.’
‘But instead you actually spent years working on something which was so utterly . . . ’ he searches for the right word, ‘ . . . evil. And I never knew.’ He pauses, and then shakes his head. ‘How could you? Why didn’t you just refuse once you knew what it was?’
Joan casts her eyes down. ‘It may seem evil now, but it wasn’t so black-and-white back then. We had to get there first, ahead of Germany.’
‘But they were nowhere near. Surely that was obvious, even at the time. All their theoretical physicists were Jews and had emigrated or been imprisoned. They were pretty much starting from scratch.’
‘How could we have known that for sure? We couldn’t take the risk. And besides, we thought we were doing something worthwhile.’
Nick rolls his eyes. ‘Oh, come on. You can’t expect me to believe that.’
‘But it’s true. That’s how we saw it.’
‘A super-bomb? How can that ever be worthwhile?’
Joan shakes her head. ‘Not the bomb. The science of it.’ She remembers this very clearly, the shared belief among the scientists involved in the project that after the war there would be incalculable benefits from their discoveries, not just in energy sources, but potentially in medicine too. Until that moment, nuclear physics had never been an applied science in the way that biology and chemistry were, and there was a sense of excitement about the seemingly limitless possibilities this implied. Joan does not expect Nick to understand this. Nobody else does. There is such a haze of history separating the past from the present, such a terrible barrier of knowledge, that it is almost impossible to describe the bright light of idealism from such a distance. ‘I have wanted to tell you before now,’ she says at last, ‘but it was so long ago.’ She pauses. ‘And I didn’t think you’d believe me.’
‘That’s not much of an excuse. I might even have been impressed. I knew you’d been to Cambridge but I hadn’t ever really thought about how unusual that must have been at the time. I always saw you as, well, just a mum.’ He pauses, pressing his knuckles into his palm. ‘I wish you’d told me.’
‘It was in the past. Your father and I . . . ’ she sighs. ‘Well, he didn’t want it mentioned, and nor did I really. I promised him.’
Nick acknowledges this point with an incline of his head, but he does not soften. ‘So he did know, then?’
Joan nods. ‘Yes, he knew,’ she says hesitantly. ‘That’s why we moved to Australia.’
‘But I thought you met on the boat going over to Australia.’
‘Well, we knew each other before then but we decided it would be easier if we pretended . . . ’
Nick makes an exasperated noise. ‘I don’t believe this. Is anything you’ve ever told me actually true?’
‘Everything I’ve told you that relates to you is true, I promise.’
There is a pause while Nick considers this qualification. ‘How can you say that this doesn’t relate to me?’
‘We’d agreed not to talk about it. I’d made your father a promise. It was a new start. You were a new start.’
She has told Nick this part before, that he was a new start for them, but she has never gone into the details of it: how much she had longed for him, dreamt of him, ached for him, before their application for adoption was approved. She has always believed that knowing how much he was wanted would be too much of a burden for him, and so she has held it back, the hope and anguish of those years when they first arrived in Australia, before the doctor finally confirmed that no, there was no chance of a baby from Joan’s damaged womb, and had they thought about adoption?
This had prompted another long process, and an uncertain one, being told repeatedly that there was something not quite right about their papers although the irregularity was never specified. They were bypassed again and again, until one day Joan received a letter saying that their application had been successful and would they please come to the Royal Victoria Hospital in three months’ time to collect their baby.
She will never forget the assault of emotion that hit her when she first picked him up in her arms and felt Nick’s soft, tiny hand close around her finger. Nothing could have prepared her for this. She remembers it as a magical time; the milky, dewy smell of him, the way his eyes changed from blue to a deeper, richer colour, almost green for a while, and then finally hazel, as astonishing as a leaf in autumn. She recalls marvelling at his tiny peachy head, his little feet, thinking how light he was, how delicate, so different from the golden-skinned little boy she had once imagined for herself and yet, at the same time, so perfect. A new start.
But now Nick is standing in front of her with his arms crossed, his initial disbelief having turned to cynicism. ‘I still think you could have told me.’
Joan’s voice is almost a whisper. ‘Like I said, nobody talked about what they did during the war. We all knew we weren’t allowed to. I didn’t even tell my family.’
Nick looks at her. ‘But Leo knew, didn’t he?’
Joan blinks. She knows that nothing has been proven. She doesn’t have to say anything. ‘No,’ she says, but the hesitation is too long.
Extract from the ‘Organisation of Tube Alloys’
14 April 1941
The objectives of the Tube Alloys project are two-fold: firstly the manufacture of the most formidable military weapon yet conceived, and, seco
ndly, the release of atomic energy for power purposes.
The scientific background of this work was well known before the war, and nothing is more certain than that the same subjects are being industriously pursued in Germany. There is, therefore, a race against time between the Allies and the Axis powers to be the first to possess the military weapon. Whatever may be the prospect of success in a reasonable time, it is clear that the subject must be pursued with the utmost speed, regardless of cost.
Joan’s billet is in a rooming house for single women run by Mrs. Landsman, situated in the rather unglamorous location of Mill Road. She goes to visit her parents as often as she can now that there is less to occupy her time in Cambridge with so many people having been sent away or posted elsewhere. Her mother has joined the Women’s Voluntary Service and is helping to run a mobile canteen until she is forced to stop after a huge metal vat is dropped on her foot in the kitchen. Her foot will recover, the doctor says, but for now she winces when she puts any weight on it, struggling with the crutches as she catches and clips them against the furniture.
On top of this, Joan’s father seems to have aged enormously in the three years since Joan left home. He retired the previous year, but rather than improving his health by giving him the opportunity to rest, this enforced inactivity only seems to have accelerated his decline. His hair, once thick and white, is thinner, and his dark eyebrows stand out more clearly against his new pallor. Even his eyes seem to have lost some of their colour. When he takes off his suit jacket and loosens his collar at the dining table, his fingers shake a little and his mouthfuls are small and laboriously chewed.
Red Joan Page 14