Massy threw back his head and gazed at the sky for a very long time. Nothing. He looked down at Riki.
“Look at the sky,” he commanded.
She raised her eyes. She had been watching him. But as she gazed upward she almost cried out. The sky was filled with stars in innumerable variety. But the brighter ones were as stars had never been seen before. Just as the sun in daylight had been accompanied by its sundogs—pale phantoms of itself ranged about it—so the brighter distant suns now shone from the center of rings of their own images. They no longer had the look of random placing. Those which were most distinct were patterns in themselves, and one’s eyes strove instinctively to grasp the greater pattern in which such seeming artifacts must belong.
“Oh … beautiful!” cried Riki softly, yet almost afraid.
“Look!” he insisted. “Keep looking!”
She continued to gaze, moving her eyes about hopefully. It was such a sight as no one could have imagined. Every tint and every color; every possible degree of brightness appeared. And there were groups of stars of the same brilliance which almost made triangles, but not quite. There were rose-tinted stars which almost formed an arc, but did not. And there were arrays which were almost lines and nearly formed squares and polygons, but never actually achieved them.
“It’s … beautiful!” said Riki breathlessly. “But what must I look for?”
“Look for what isn’t there,” he ordered.
She looked, and the stars were unwinking, but that was not extraordinary. They filled all the firmament, without the least space in which some tiny sparkle of light was not to be found. But that was not remarkable, either. Then there was a vague flickering grayish glow somewhere indefinite. It vanished. Then she realized.
“There’s no aurora!” she exclaimed.
“That’s it,” said Massy. “There’ve always been auroras here. But no longer. We may be responsible. I wish I thought it wise to turn everything back to reserve power for a while. We could find out. But we can’t afford it. There was just the faintest possible gray flickering just now. But there ought to be armies of light marching across the sky. The aurora here—it was never missing! But it’s gone now.”
“I … looked at it when we first landed,” admitted Riki. “It was unbelievable! But it was terribly cold, out of shelter. And it happened every night, so I said to myself I’d look tomorrow, and then tomorrow again. So it got so I never looked at all.”
Massy kept his eyes where the faint gray flickering had been. And once one realized, it was astonishing that the former nightly play of ghostly colors should be absent.
“The aurora,” he said dourly, “happens in the very upper limits of the air … fifty … seventy ... ninety miles up, when God-knows-what emitted particles from the sun come streaking in, drawn by the planet’s magnetic field. The aurora’s a phenomenon of ions. We tap the ionosphere a long way down from where it plays, but I’m wondering if we stopped it.”
“We?” said Riki, shocked. “We—humans?”
“We tap the ions of their charges,” he said somberly, “that the sunlight made by day. We’re pulling in all the power we can. I wonder if we’ve drained the aurora of its energy, too.”
Riki was silent. Massy gazed, still searching. But he shook his head.
“It could be,” he said in a carefully detached voice. “We didn’t draw much power by comparison with the amount that came. But the ionization is an ultraviolet effect. Atmospheric gases don’t ionize too easily. After all, if the solar constant dropped a very little, it might mean a terrific drop in the ultraviolet part of the spectrum—and that’s what makes ions of oxygen and nitrogen and hydrogen and such. The ion-drop could easily be fifty times as great as the drop in the solar constant. And we’re drawing power from the little that’s left.”
Riki stood very still. The cold was horrible. Had there been a wind, it could not have been endured for an instant. But the air was motionless. Yet its coldness was so great that the inside of one’s nostrils ached, and the inside of one’s chest was aware of chill. Even through the cold-garments there was the feeling as of ice without.
“I’m beginning,” said Massy, “to suspect that I’m a fool. Or maybe I’m an optimist. It might be the same thing. I could have guessed that the power we could draw would drop faster than our need for power increased. If we’ve drained the aurora of its light, we’re scraping the bottom of the barrel. And it’s a shallower barrel than one would suspect.”
There was stillness again. Rild stood mousy-quiet. When she realizes what this means, thought Massy grimly, she won’t admire me so much. Her brother’s built me up. But I’ve been a fool, figuring out excuses to hope. She’ll see it.
“I think,” said Riki quietly, “that you’re telling me that after all we can’t store up heat, to live on, down in the mine.”
“We can’t,” agreed Massy grimly. “Not much, nor long. Not enough to matter.”
“So we won’t live as long as Ken expects?”
“Not nearly as long,” said Massy evenly. “He’s hoping we can find out things to be useful back on Lani II. But we’ll lose the power we can get from our grid long before even their new grids are useless. We’ll have to start using our reserve power a lot sooner. It’ll be gone—and us with it—before they’re really in straits for living-heat.”
Riki’s teeth began to chatter.
“This sounds like I’m scared,” she said angrily, “but I’m not! I’m just freezing! If you want to know, I’d a lot rather have it the way you say! 1 won’t have to grieve over anybody, and they’ll be too busy to grieve, for me! Let’s go inside while it’s still warm!”
He helped her back into the cold-lock, and the outer door closed. She was shivering uncontrollably when the warmth came pouring in.
They went into Herndon’s office. He came in as Riki was peeling off the top part of her cold-garments. She still shivered. He glanced at her and said to Massy:
“There’s been a call from the grid-control shack. It looks like there’s something wrong, but they can’t find anything. The grid is set for maximum power-collection, but it’s bringing in only fifty thousand kilowatts!”
“We’re on our way back to savagery,” said Massy, with an attempt at irony.
It was true. A man can produce two hundred and fifty watts from his muscles for a reasonable length of time. When he has no more power, he is a savage. When he gains a kilowatt of energy from the muscles of a horse, he is a barbarian—but the new power cannot be directed wholly as he wills. When he can apply it to a plow he has high barbarian culture, and when he adds still more he begins to be civilized. Steam power put as much as four kilowatts to work for every human being in the first industrialized countries, and in the mid-twentieth century there was sixty kilowatts per person in the more advanced nations. Nowadays, of course, a modern culture assumed five hundred as a minimum. But there was less than half that in the colony on Lani II. And its environment made its own demands.
“There can’t be any more,” said Riki, trying to control her shivering. “We’re even using the aurora and there isn’t any more power. It’s running out. We’ll go even before the people at home, Ken.”
Herndon’s features looked very pinched.
“We can’t! We mustn’t!” He turned to Massy. “We do them good, back home! There was panic. Our report about cable grids has put heart in people. They’re setting to work—magnificently! So we’re some use! They know we’re worse off than they are, and as long as we hold on they’ll be encouraged! We’ve got to keep going somehow!”