Murray Leinster

“ 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. ”

“ Colonized worlds are like isolated islands in an unimaginably vast ocean, and the ships that ply between them at thirty light-speeds seem merely to creep. In ancient days on the mother planet Earth, men sailed for months between ports, in their clumsy sailing ships. ”

“ They were young men, technicians rather than scientists. Some of them were several years younger than Massy. There were grim and stunned expressions on some faces, but one tried to pretend nonchalance, and two seemed trying to suppress fury at the monstrous occurrence that would destroy not only their own lives, but everything they remembered on the planet which was their home. They looked almost challengingly at Massy.
He explained. He was going to put a cloud of metallic vapor up in the ionosphere. Sodium if he had to, potassium if he could, zinc if he must. ”

“ Massy reached the base of the grid on foot. It was not far from the village of drone-hulls. He was dwarfed by the ground-level upright beams. He went through the cold-lock to the small control-house at the grid's base.
He nodded to the man on standby as he got painfully out of his muffling garments.
"Everything all right?" he asked.
The standby operator shrugged. Massy was Colonial Survey. It was his function to find fault, to expose inadequacies in the construction and operation of colony facilities. It's natural for me to be disliked by men whose work I inspect, thought Massy. ”

“ He held out his hand quickly as she slipped, once.
"But they'll beat it!" said Riki in a sort of angry pride. "They're starting to build more landing-grids, back home. Hundreds of them! Not for ships to land by, but to draw power from the ionosphere! They figure that one ship-size grid can keep nearly three square miles of ground warm enough to live on! They'll roof over the streets of cities. Then they'll plant food-crops in the streets and gardens, and do what hydroponic growing they can. They are afraid they can't do it fast enough to save everybody, but they'll try!" ”

“ Massy frowned. Sunspots are things about which nothing can be done. Yet the habitability of a borderline planet, anyhow, can very well depend on them. An infinitesimal change in sun heat can make a serious change in any planet's temperature. In the books, the ancient mother planet Earth was said to have entered glacial periods through a drop of only three degrees in the planet-wide temperature, and to have been tropic almost to its poles from a rise of only six. It had been guessed that glacial periods in the planet where humanity began had been caused by coincidences of sunspot maxima. ”

“ A landing-grid has to be not less than half a mile across and two thousand feet high because its field has to reach out five planetary diameters to handle ships that land and take off. To handle solid objects it has to be accurate—though power can be drawn with an improvisation. To thrust a sodium-vapor bomb anywhere from twenty to fifty miles high—why—he'd need a grid only six feet wide and five high. ”

“ When he was alone again, Massy thought, Maybe it's worth doing because it'll get Riki on the Survey ship. But they think it means saving the people back home!
Which it didn't. Taking energy out of sunlight is taking energy out of sunlight, no matter how you do it. Take it out as electric power, and there's less heat left. Warm one place with electric power, and everywhere else is a little colder. There's an equation. On this colony-world it wouldn't matter, but on the home world it would. The more there was trickery to gather heat, the more heat was needed. ”

“ Massy looked up. Herndon's face was ghastly. Massy said in some grimness:
"Kent IV's the nearest world your planet could hope to get help from. A mail liner will make it in two months. Kent IV might be able to send three ships—to get here in two months more. That's no good!"
He felt sick. Human-inhabited planets are far apart. The average distance of stars of all types—there is on an average between four and five light-years of distance between suns. They are two months' spaceship journey apart. And not all stars are sol-type or have inhabited planets. ”

“ Riki ground her teeth.
"Go on!" she said challengingly.
"Ionization here is down ten per cent," said Massy. "That means the voltage is down—somewhat more. A great deal more. And the resistance of the layer is greater. Very much greater. When they need power most, on the home planet, they won't draw more from a grid than we do now. It won't be enough."
They reached the village. There were steps to the cold-lock of Herndon's office-hull. They were ice-free, because like the village walkways they were warmed to keep frost from depositing on them. Massy made a mental note. ”

“ The inner planet, Lani II, had twenty millions of inhabitants, as against the three hundred people in the colony on Lani III. The outer planet was already frozen, but there would be glaciation on the inner world in two hundred days. Glaciation and human life are mutually exclusive. Human beings can survive only so long as food and power hold out, and shelter against really bitter cold cannot be improvised for twenty million people! ”

“ The height to which carbon dioxide existed was dropping—slowly, but inexorably. And above the carbon-dioxide level there was no bottom limit to the temperature. The greenhouse effect was due to CO2. Where it wasn't, the cold of space moved down. If at ground-level the thermometer read ever so slightly lower than one hundred and nine below zero—why—everything was finished. Without the greenhouse effect, the night-side of the planet would lose its remaining heat with a rush. Even the day-side, once cold enough, would lose heat to emptiness as fast as it came from the sun. ”

“ Human life would be quite simply impossible, in any shelter and under any conditions. Even spacesuits would not protect against an atmosphere sucking heat from it at that rate. A spacesuit can be heated against the loss of temperature due to radiation in a vacuum. It could not be heated against nitrogen which would chill it irresistibly by contact.
But, as Massy sweated over it, the thermometer steadied at minus eighty-five degrees. When the dawn came, it rose to seventy. By mid-morning, the temperature in bright sunshine was no lower than sixty-five degrees below zero. ”

“ A brick-well draws water from all around its circumference.
So Massy computed carefully. It was ironic that he had to go to such trouble simply because he didn't have test-rockets like the Survey uses to get a picture of a planet's weather-pattern. They rise vertically for fifty miles or so, trailing a thread of sodium-vapor behind them. The trail is detectable for some time, and ground-instruments record each displacement by winds blowing in different directions at different speeds, one over the other. Such a rocket with its loading slightly changed would do all Massy had in mind. ”

“ The miniature grid could lift and hold a bomb steady in its field-focus at seven hundred and fifty thousand feet. But if a bomb was accelerated all the way out to that point, and the field was then snapped off—Why, it wasn't held anywhere. It kept on going with its attained velocity. And it burst when its fuse decided that it should, whereupon immediately a mass of sodium and potassium vapor, mixed with the fumes of high explosive, flung itself madly in all directions, out between the stars. Absolute vacuum tore the compressed gasified metals apart. ”

“ It couldn't support life, because life is always dependent on other life, and there is a temperature below which a natural ecological system can't maintain itself. The past few weeks, the climate had been such that even human-supplied life looked dubious.
Massy slipped on his Colonial Survey uniform with its palm-tree insignia. Nothing could be much more inappropriate than palm-tree symbols on a planet with sixty feet of permafrost. Massy reflected wryly, The construction gang calls it a blast, instead of a tree, because we blow up when they try to dodge specifications. ”

“ It is carbon dioxide which is responsible for the greenhouse effect, by which a planet is in thermal equilibrium only at a temperature above its surroundings—as a greenhouse in sunlight is warmer than the outside air. ”

“ 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. ”

“ Worse, the heat radiated from a sun's photosphere varies not as the square or cube, but as the fourth power of its absolute temperature. A very small change in the sun's effective temperature, producible by sunspots, could make an altogether disproportionate difference in the warmth its worlds received.
Massy's computations were not pure theory. The data came from Sol itself, where alone in the galaxy there had been daily solar-constant measurements for three hundred years. ”

“ But individual atoms of the lighter alkaline-earth metals have marked photo-electric properties. In sunshine these gas-molecules ionized, and therefore spread more widely, and did not coalesce into even microscopic droplets.
They formed, in fact, a cloud in space. An ionized cloud, in which no particle was too large to be responsive to the pressure of light. The cloud acted like the gases of a comet's tail. It was a comet's tail, though there was no comet. And it was an extraordinary comet's tail because it is said that you can put a comet's tail in your hat, at normal atmospheric pressure. ”

“ She jerked her head toward a port which let in the frigid colony-world's white daylight. Her face worked.
Massy was aware of an extreme unhappiness on her account. For himself, of course, the tragedy was less. He had no family. He had very few friends. But he could see something that had not occurred to them as yet.
"Of course," he said, "it's not only their trouble. If the solar constant is really dropping like that ... why things out here will be pretty bad too. A lot worse than they are now. We'll have to get to work to save ourselves!"
Riki did not look at him. Herndon bit his lips. ”

“ He'd been a Survey Candidate on Khali II and Taret and Arepo I, all of which were tropical, and a Junior Officer on Menes III and Thotmes—one a semiarid planet and the other temperate-volcanic—and he'd done an assistant job on Saril's solitary world, which was nine-tenths water. But this first independent survey on his own was another matter. Everything was wholly unfamiliar. An ice planet with a minus point one habitability rating was upsetting in its peculiarities. ”

“ Getting the Survey ship to ground won't help now, since Riki's forewarned. And this trick won't solve anything permanently on the home planet. It'll just postpone things.
He had a very peculiar ache inside. A Survey officer is naturally lonely. Massy had been lonely before he even entered the Service. He hadn't had a feeling of belonging anywhere, or with anyone, and no planet was really his home. Now he could believe that he belonged with someone. But there was the slight matter of a drop in the solar constant of an unimportant sol-type sun, and nothing could come of it. ”

“ The voltage and the conductivity of the layer we draw power from, both depend on ionization. When the intensity of sunlight drops, the voltage drops and the conductivity drops, too. It's harder for less power to flow to the area the grid can tap—and the voltage-pressure is lower to drive it. ”

“ They couldn't store enough heat for so long. It couldn't be done. It was ironic that in the freezing of ice and the making of glaciers the planet itself could store cold.
And there would be monstrous storms and blizzards on Lani II as it cooled. As cold conditions got worse the wire grids could be held aloft for shorter and shorter periods, and each time they would pull down less power than before. Their effectiveness would diminish even faster than the need for effectiveness increased.
Massy felt even deeper depression as he worked out the facts. ”