1While the armies lay in their ditches, the clerk of Bern sat in a cold room in Berlin and finished the hardest work of his life.
2He was a clerk no longer. The masters of Berlin had called him to sit among them, and he had come in the last spring of the peace. Then the war began, and his wife took their two sons back to the Swiss country, and he lived alone among papers, eating out of tins, forgetting to sleep.
3For eight years one thing had troubled him in his own teaching. He had shown how time and length change for travellers who move smoothly past one another. But the world is not smooth. Things fall. Newton had given the rule of falling and had said, honestly, that he did not know the cause. A stone and the earth pull upon each other across empty space, at once, with nothing between them. How?
4The answer began with a thought so plain that he called it the happiest of his life. A man falling from a roof does not feel his own weight. While he falls, his hat and his pipe fall beside him and seem to float. For him, for that little while, there is no heaviness at all.
5From that seed, in eight years, a whole tree grew. Here is its shape, as nearly as plain words can give it.
6Space and time are not an empty stage on which things happen. They are a cloth, one cloth, and the things of the world lie in it and press upon it. A great weight like the sun makes a hollow in the cloth around itself. The earth does not circle the sun because a rope pulls it. The earth goes as straight as it can, and the straightest road through a hollow is a circle.
7Nothing reaches across the dark. The Weave itself is bent, and everything in it follows the bend.
8The numbers of this were cruelly hard. Twice he thought he had them and was wrong. In the second autumn of the war he worked in a kind of fever, giving a new paper to the masters every week, each one mending the last.
9There was one old trouble in the sky that he used as his test. The small planet nearest the sun does not quite keep to its ring. Its path creeps round, year by year, by a hair more than Newton's rule allows. For sixty years the star-counters had hunted for a hidden world that might be tugging it. There was none.
10In November he set his new rule against that planet and worked the sum. Out came the creeping, to the hair, with nothing added. He wrote afterward that for some days he was beside himself with joy, and that his heart had shaken in his chest.
11A week later he gave the masters the finished law. It filled one line.
12Now hear who first answered him, and from where.
13On the Russian front that winter there was a German officer of the guns named Karl Schwarzschild. In peace he had been the keeper of a great house of star-watching. He was past forty and need not have gone to war, but he had gone, and now he reckoned the flight of shells in the snow, and a sickness had begun in his skin that no doctor could stop.
14The clerk's paper reached him in a dugout. Between the firing of the guns, by a lamp, in a few weeks, he did what its own maker had thought could not be done so soon: he solved the new law exactly, for the hollow round a single star. He posted the answer to Berlin with a note saying how kind the war had been, to let him walk this little way into the land of such ideas in spite of the gunfire.
15The clerk read it out before the masters. In May the officer was dead, of the sickness. He had opened a door at the edge of his own grave, and it is in use to this day.
16But a sum that fits one planet is not yet proof. The new law made a second promise, and it could be tested only in the sky.
17If the sun truly makes a hollow in the Weave, then the light of a far star, passing close beside the sun on its way to us, must go round the edge of the hollow and be turned a little aside. So a star seen near the sun's rim should seem to stand a hair out of its true place.
18Newton's rule, pushed as far as it would go, allowed a small turning. The new law said: twice as much. There was the test. One number or the other.
19But no one can see a star beside the sun. The sun drowns them. There is only one time when it can be done: in the few minutes of a full eclipse, when the moon covers the sun's face and the stars come out at noon.
20And the papers that held this promise lay in Berlin, in the tongue of the enemy, in the middle of a war.
21They crossed all the same. A wise man of Holland, which had stayed out of the fighting, sent them on to England. There they came into the hands of the one man in that country best fitted to read them.
22His name was Arthur Eddington, and he kept the stars at Cambridge. He was thirty-three, quick and shy, a great rider of bicycles. And he was of the people called Friends, who hold that there is a light in every person, and who will not take up a weapon against anyone for any king.
23In those years, in England, they were burning German books and stoning German shops. Learned societies were striking the names of German masters off their rolls. Eddington stood up among his fellows and said that the work of finding out belonged to all nations, and that this new thing out of Berlin was the greatest thought of the age.
24They did not thank him for it.
25Then the army called him. He was of an age to fight. His college asked that he be spared for his usefulness; he might have let that stand and said nothing. Instead he wrote on the paper, in his own hand, that even if he were not spared for his work, he would refuse on account of his faith. He knew what that meant. Other Friends from Cambridge were at that hour peeling potatoes in prison camps, and worse.
26The keeper of the King's own observatory saved him, and did it cleverly. He went to the men of the navy and told them that there would be an eclipse in the year after next, the best for this purpose in a lifetime, with the sun standing in front of a thick field of bright stars. Let this man be left free to make ready, he said, and if the war is over, let him lead the journey.
27So it was written down, with seals: Arthur Eddington is excused from the war, on condition that he go to the ends of the earth and find out whether an enemy is right.
28The war ended in the eleventh month of its fourth year. Four months later, with the mines still drifting in the sea-lanes, two parties sailed from Liverpool. One went to the coast of Brazil. Eddington, with a clock-maker named Cottingham, went to a small island of cocoa trees off the west of Africa, named Príncipe, which lies almost under the line of the world's middle.
29They were weeks at sea, and weeks more on the island, building. They set up their long glass on a planter's land above the bay. They hung nets against the mosquitoes. Monkeys stole from the stores. It was the season of rain, and day after day the sky was a grey lid.
30Know what they carried, besides the glass. They carried the hope of a man in Berlin who was thin with hunger, for the war had starved that city and he had been months in bed. They carried, too, a thing they did not speak of. If this could be done, an Englishman would have crossed the sea, with the dead not yet counted, to prove a German right. Something would have been mended that the guns had torn.
31The day came: the twenty-ninth of May. The moon's shadow was to pass a little after two in the afternoon, and to last five minutes. Five minutes, after two years of making ready and four thousand miles of sea.
32At dawn it was raining as he had never seen rain. The water stood in sheets on the ground. Thunder walked round the island all morning. Cottingham looked at the sky and said nothing. Eddington checked the clockwork and the plates again and said nothing either.
33At noon the rain stopped. The cloud did not go.
34At half past one they saw the sun for the first time, a pale coin behind grey wool, with a bite already out of it. Then the cloud closed again.
35There was no choice to make. Whether stars could be seen or not, the plates must be put through in their order, for there would be no second day. The light failed, quite quickly, as if someone were turning down a lamp. The birds went silent in the cocoa trees. A cold wind came up the hill.
36"Go," said Eddington.
37Cottingham counted the seconds aloud by the clock. Eddington pulled the dark slide, held the plate open to the sky for the count, closed it, drew it out, slid in the next. Sixteen plates. He did not look up. He wrote afterward that he never saw the eclipse at all, except for one glance at the beginning to make sure it had begun, and one in the middle to see how much cloud there was.
38In that one glance he saw the black disc of the moon with a ring of pearl fire round it, and a great red flame standing off the sun's edge, a hundred thousand miles high. It hung in a ragged hole in the cloud. Then he bent to the plates again.
39The light came back. It was over. He had no way to know what he had.
40That night, and the nights after, he washed the plates one by one in the dark. The first showed the ring of fire and no stars: cloud. The second, no stars. So with the third, and the tenth. He went on to the end.
41On two of the last plates, taken as the cloud thinned, there were stars. They were faint. There were five of them on the best plate: five small dots beside the black sun.
42He laid that plate over another, taken months before in England, of the same stars in the night sky with no sun near them. He measured the dots under a glass, to the thousandth part of a hair. It took days. He had fever. He would not let another hand do it.
43The stars had moved. Each one stood a little outward from the sun, as if the sun had pushed the sky apart with its two hands. And when he worked the sum, the turning was not Newton's number. It was the other one.
44He turned to Cottingham and told him. Long after, he said that this was the greatest moment of his life.
45The plates from Brazil, when they were measured, said the same, for there the sky had cleared in time.
46In November the learned men of England met in London, in a room where a painted Newton looked down from the wall. The keeper of the King's observatory stood and read the numbers. Then the old chief of the meeting rose and said that this was one of the highest things ever done by human thought. No one in the room moved for a while.
47Within days the clerk of Bern, in his cold rooms in Berlin, found that he was the most famous man alive. He did not much like it, then or ever.
48But look at what else had happened in that room. For two hundred years Newton's rule had been the surest thing that people knew. It had weighed the planets and timed the tides. And it was not quite right. It was a true map of the valley, and failed only at the edge, where no one had been.
49The Weave has laws, and they can be read. That was learned long before. Now something was added: the reading is never finished. The best map is still a map. The one who draws it must leave the edge open, and bless the one who comes to draw it further.
50Newton would not have minded. He had said himself that he did not know the cause.
51And look at who did it. A German found the law, in a starving city. A German soldier, dying, gave it its first answer from a hole in the snow. A man of Holland passed it across the line. An Englishman who would not fight carried it to an island and held it up against the sun. They did not agree to do this. Their kings had forbidden them even to write to one another. But the One Hearth is not put out by a war. It only burns lower for a while, and waits for someone to walk across with open hands.
52Word had reached him some weeks earlier, by a telegram from Holland. It is told that he showed it to a pupil calmly, as if he had never doubted. Perhaps that is so. But he wrote to his mother that same day, and the card is still kept. It begins as any glad son would begin: there was joyful news today.
53He was sure of his law, and he was glad to be shown that he was right. Both things were true of him. Hold on to both, for you will need them when you hear what the new century had still to teach him: that there are things in the Weave which even he could not make sure of, and that the light he had measured could be put to another use.