1The letter that the old man signed by the water lay for a time on a ruler's desk. Then the war spread over the whole earth, and the thing was begun in earnest. It became the largest work that had ever been done in secret.
2They needed a place where no one came. They chose a flat-topped hill in the high desert of New Mexico, among pines, with a boys' school on it and one bad road. It was called Los Alamos. The man who chose it had ridden there on horseback as a sick youth, and had said once that his two loves were physics and the desert, and that it was a pity they could not be joined.
3His name was Robert Oppenheimer. He was thirty-eight, tall and very thin, with blue eyes that people did not forget. He had been a rich man's son in New York, a child who collected stones and read poems in six tongues. He had learned the old speech of India so that he could read its sacred song in its own words.
4They made him master of the hill. He gathered there the best of his science from every free nation, and many who were exiles from the unfree ones. Thousands came, with wives and small children, to a town that was on no map. Most were under thirty. They worked as people work who believe that somewhere a clock is running against them.
5For they believed that Berlin was ahead. That was the whole reason.
6Now hear a thing that is seldom told. In the last winter of the war, word came to the hill, quietly, that the fear was empty. The Germans had tried and got nowhere. There would be no bomb from Berlin.
7One man packed his bag. He was a Pole named Rotblat. He went to the masters of the hill and said: I came to stop one thing, and that thing is not coming. I have no more business here. They let him go, and warned him to keep silent. Of all the thousands, he was the only one who left for that cause.
8The rest stayed. The work was so nearly done. The war with Japan was still burning. And there is a pull in a hard problem almost solved that is as strong as any pull on earth. Oppenheimer said it himself, years after: when you see something that is sweet to make, you go ahead and make it, and you argue about what to do with it only when you have had your success.
9Germany fell in the spring. The work went faster.
10In July they carried the first of the things out into a wide dry plain to the south, which the old Spanish travellers had named the Journey of the Dead Man. They hauled it to the top of a tower of steel as high as a ten-storey house. It was a ball about the height of a man, bristling with wires. At its heart was a lump of grey metal no bigger than an orange.
11There was a question that some had asked, earlier, and it had been answered with careful sums. The question was whether so great a heat might set fire to the air itself, and so run round the world. The sums said no. But on that last night, one of the masters went about offering to take wagers on whether they were about to burn up only the desert, or the whole earth. He meant it as a jest to ease the waiting. Not everyone laughed.
12Think what it is, to be the first creatures who ever had to ask.
13The rain stopped before dawn. They lay down in trenches, miles off, with their feet toward the tower and dark glass over their eyes. Oppenheimer stood in a bunker of earth and timber, holding on to a post. Those beside him said that through the last seconds he did not seem to breathe.
14Then there was a light.
15It was not like a fire being lit. The whole sky and the whole land were light at once, white, and then gold and purple, with no shadows in them. The mountains stood out, every fold of them, brighter than at noon. Men ten miles away felt heat on their faces as from an oven door. And for a long time there was no sound at all.
16Then the sound came and went on and on between the mountains. And a ball of fire rose up boiling, and under it a pillar of dust, until it stood seven miles high over the plain in the first grey of the true morning. For that day had two sunrises, and the second was the weaker.
17When they could go near, days later, the tower was gone. It had not fallen. It was not there. And for hundreds of paces around, the sand of the desert had melted and set into a sheet of green glass.
18Of that moment Oppenheimer said, when he was old: "We knew the world would not be the same." A few people laughed, he said, and a few cried, and most were silent.
19And he said that a line had come into his mind from the sacred song of India, where the god shows himself to the prince in his dreadful form. In the words he gave it: "Now I am become Death, the destroyer of worlds."
20Some of the makers had signed a paper, in those last weeks, begging their ruler not to use the thing on a city without a warning first, and a chance to yield. Szilard wrote it, who had seen the chain at a London kerb. Seventy put their names. It was passed upward from desk to desk. It did not reach the ruler in time.
21Now go to the other side of the world.
22There was a city in Japan called Hiroshima, built on the flat mouths of a river, with seven streams running through it and many bridges. It had not been bombed in all the war, and its people wondered why.
23In that city lived a girl named Chiyo, who was fifteen. The men had all gone to the war, so the trams were run by schoolgirls. She wore a cap and a leather bag, and punched the tickets on the line that went to the harbour. In the evenings she had lessons at the tram company's school, and slept there in a long room with forty others. She was proud of the cap.
24The sixth of August was a clear hot morning. Early there had been a warning and then the all-clear; one aeroplane, very high. People had come out of the shelters and gone to their work. Chiyo was not on the first shift. She was hanging washing in the yard of the school, on the south side of the city, a mile and more from its centre.
25At a quarter past eight there was a light.
26She did not hear anything. She said afterward that the whole air turned white, and that she felt the heat on the side of her face and on the backs of her hands. Then the school wall came down, and she was under it.
27She dug herself out. She was cut, and one arm was burned, but she could walk. The sky had gone dark as evening, and where the city had been there was a brown cloud, and fire under it.
28What she saw that day, walking in toward the centre to look for her friends on the morning shift, shall not be set down here in full. She saw the trams. They stood on their rails where the light had caught them, burned black, and the people in them had not had time to stand up. She saw the river full. She saw, on the stone steps of a house of money, the shadow of someone who had been sitting there, printed on the stone, and no one to cast it.
29Seventy thousand people died in that one morning, from one aeroplane, from one lump of metal. As many again died before the year was out, of the burning and of the unseen rays that the woman of Paris had first met in a shed. Three days later a second city, Nagasaki, was struck in the same way. Then the war ended.
30Mark the count. In the first great war it had taken four years and all the factories of Europe to close ten million lives. Now a city could be closed between one breath and the next. And every one of the makers knew that this was only the first and smallest of its kind. Larger ones could be built, and would be, and enough of them for every city there is. For ten thousand years the worst hand in the world could burn a town, a land, a people. The rest of the earth went on. And now?
31Sit with that. But it is not the last verse of this chapter. Hear what Chiyo did.
32On the second day a man from the tram company found her among the hurt at the school. Many of the girls were dead. Most of the cars were burned. He told her that one stretch of line on the west side had been cleared, and that they had found a car that would run. He asked whether she could stand.
33On the third day after the light, a single tram went out along that stretch, through the ash, with a schoolgirl driving and a schoolgirl taking no fares. The company had said that everyone should ride free.
34People came out of the ruins when they heard the bell. They stood by the track and stared. Some bowed to it. An old man climbed up, with his feet wrapped in rags, and sat down on the bench, and held on to the rail, and wept without making a sound. Chiyo had her cap on, and a bandage under it. She said, "Mind the step."
35It was said in that city that nothing would grow there for seventy-five years. In the autumn the weeds came up through the ash. The next summer the burned trees put out leaves from their black trunks, and the red flowers of the oleander opened along the rivers.
36Now hear how the makers carried it.
37Oppenheimer went to the ruler of his country and said that he felt he had blood on his hands. The ruler was angry, and told his servants not to bring that man to him again. Two years later, speaking to others of his science, Oppenheimer said: "In some sort of crude sense which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose."
38He did not say that the knowledge should be unlearned. It cannot be. He gave the rest of his strength to asking that the new fire be put under the guard of all nations together and not of one.
39The old man of Princeton heard the news of Hiroshima in a cottage by a lake. He had signed one letter and done nothing else, and he did not hide behind that. He spent the ten years he had left warning anyone who would listen. He wrote: "The unleashed power of the atom has changed everything save our modes of thinking and we thus drift toward unparalleled catastrophe."
40Everything save our modes of thinking. There is the task, said in six words. The fire had grown. The hand that holds it had to grow as much, and quickly.
41And was there anywhere a new mode of thinking to be found? Listen. This is the last thing.
42You remember the runner in the meadow, Alan Turing, who dreamed the pattern of every reckoning-machine. In the war he had worked in a wooden hut in the English country, and there he and others built machines of wheels and wire that broke the secret speech of the enemy's hunting ships. By that, the bread-ships crossed the ocean, and the war was shortened, by some reckonings, by two years. Almost no one was told of it for thirty years.
43In the middle of that war he crossed the ocean on secret business, and for two months he took his tea each afternoon, in the eating-hall of a great house of telephone-makers in New York, with a quiet American a few years younger than himself. The American's name was Claude Shannon. Neither was allowed to tell the other what he was working at. So they talked of something else: whether a machine could be built that would think.
44They parted. Turing went home. After the war he went north to the city of Manchester, where a machine of his pattern had at last been built. It filled a room. It kept its thoughts as a pattern of small green lights on the face of a glass tube, and a person could stand in the dark and watch them change.
45A glow in the dark again: not the blue of the radium in the shed, that had led to the second sun, but a cool green, that did nothing but hold a number and give it back. He sat before it at night as the first keeper had sat before the horn.
46In the fiftieth year of the century, with half of it lying in ashes behind him, he wrote a paper asking whether such a thing could one day be called a mind. He did not claim to know. He ended it with a line that will serve for the end of this book:
47"We can only see a short distance ahead, but we can see plenty there that needs to be done."
48And across the sea, in a quiet room among the telephone-makers, the man he had taken tea with was already counting something that no one had thought to count: not heat, not atoms, but the news itself that passes from mind to mind. He had found that it could be weighed, and that its smallest grain was a single yes or no.
49So the ember passed: out of the ash of two cities, over the water, into a small green light and a count of yes and no. It was a little thing to set against the second sun. A coal in a horn is a little thing too. Now hear what came of it.