The Black Star Passes - John W. Campbell (reading cloud ebooks txt) 📗

was a roar like a fifty-foot wind tunnel, and a mighty blast of cold air swept out of that coil like a six-inch model of a Kansas cyclone. Every loose piece of paper in the laboratory came suddenly alive and whirled madly before the blast of air that had suddenly leaped out. Dr. Arcot was forced back as by a giant hand; in his backward motion his hand was lifted from the relay switch, and with a thud the circuit opened. In an instant the roar of sound was cut off, and only a soft whisper of air told of the furious blast that had been there a moment before.

The astonished physicist came forward and looked at the device a moment in silence, while each of the other men watched him. Finally he turned to his son, who was smiling at him with a twinkle in his eye.

“Dick, I think you have ‘loaded the dice’ in a way that is even more lucrative than any other method ever invented! If the principle of this machine is what I think it is, you have certainly solved the secret of a sufficiently absorbing area for a solar engine.”

“Well,” remarked the elderly Morey, shivering a bit in the chill air of the room, “loaded dice have long been noted for their ability to make money, but I don’t see how that explains that working model of an Arctic tornado. Burr⁠—it’s still too cold in here. I think he’ll need considerable area for heat absorption from the sun, for that engine certainly does cool things down! What’s the secret?”

“The principle is easy enough, but I had considerable difficulty with the application. I think it is going to be rather important though⁠—”

“Rather important,” broke in the inventor’s father, with a rare display of excitement. “It will be considerably more than that. It’s the biggest thing since the electric dynamo! It puts airplanes in the junk heap! It means a new era in power generation. Why, we’ll never have to worry about power! It will make interplanetary travel not only possible, but commercially economical.”

Arcot junior grinned broadly. “Dad seems to think the machine has possibilities! Seriously, I believe it will antiquate all types of airplanes, prop or jet. It’s a direct utilization of the energy that the sun is kindly supplying. For a good many years now men have been trying to find out how to control the energy of atoms for air travel, or to release the energy of the constitution of matter.

“But why do it at all? The sun is doing it already, and on a scale so gargantuan that we could never hope nor desire to approach it. Three million tons of matter go into that colossal furnace every second of time, and out of that comes two and a half decillion ergs of energy. With a total of two and a half million billion billion billions of ergs to draw on, man will have nothing to worry about for a good many years to come! That represents a flood of power vaster than man could comprehend. Why try to release any more energy? We have more than we can use; we may as well tap that vast ocean of power.

“There is one thing that prevents us getting it out, the law of probability. That’s why Dad mentioned loaded dice, for dice, as you know, are the classical example of probability when they aren’t loaded. Once they are loaded, the law still holds, but the conditions are now so changed that it will make the problem quite different.”

Arcot paused, frowning, then resumed half apologetically, “Excuse the lecture⁠—but I don’t know how else to get the thought across. You are familiar with the conditions in a liter of helium gas in a container⁠—a tremendous number of molecules, each dashing along at several miles a second, and an equal number dashing in the opposite direction at an equal speed. They are so thickly packed in there, that none of them can go very far before it runs into another molecule and bounces off in a new direction. How good is the chance that all the molecules should happen to move in the same direction at the same time? One of the old physicists of Einstein’s time, a man named Eddington, expressed it very well:

‘If an army of monkeys were playing on typewriters they might write all the books in the British Museum. The chance of their doing so is decidedly more favorable than the chance that all the molecules in a liter of gas should move in the same direction at the same time.’

The very improbability of this chance is the thing that is making our problem appear impossible.

“But similarly it would be improbable⁠—impossible according to the law of chance⁠—to throw a string of aces indefinitely. It is impossible⁠—unless some other force influences the happening. If the dice have bits of iridium stuck under the six spots, they will throw aces. Chance makes it impossible to have all the molecules of gas move in the same direction at the same time⁠—unless we stack the chances. If we can find some way to influence them, they may do so.

“What would happen to a metal bar if all the molecules in it decided to move in the same direction at the same time? Their heat motion is normally carrying them about at a rate of several miles a second, and if now we have them all go in one way, the entire bar must move in that direction, and it will start off at a velocity as great as the velocity of the individual molecules. But now, if we attach the bar to a heavy car, it will try to start off, but will be forced to drag the car with it, and so will not be able to have its molecules moving at the same rate. They will be slowed down in starting the mass of the car. But slowly moving molecules have a definite physical significance.