"I know," said Russ. "It really makes no sound. In other words it creates an electric field that doubles for sound. It ought to be just the thing because nothing can stop it. Metal shielding can, I guess, if it's thick enough, but it's got to be pretty damn thick."
It took time to set the mechanism up. Ready, the massive apparatus, within which glowed a larger and more powerful force field, was operated by two monstrous material energy engines. The controls were equipped with clockwork drives, designed so that the motion of the Earth could be nullified completely and automatically for work upon outlying planets.
Russ stood back and looked at it. "Stand in front of that screen, Greg," he said, "and we'll try it on you."
Greg stepped in front of the screen. The purr of power came on. Suddenly, materializing out of the air, came Greg's projection. Hazy and undefined at first, it rapidly assumed apparent solidity. Greg waved his arm; the image moved its arm.
Russ left the controls and walked across the laboratory to inspect the image. Examined from all sides, it looked solid. Russ walked through it and felt nothing. There was nothing there. It was just a three-dimensional image. But even from two feet away, it was as if the man himself stood there in all the actuality of flesh and blood.
"Hello, Russ," the image whispered. It held out a hand. "Glad to see you again."
Laughing, Russ thrust out his hand. It closed on nothing in mid-air, but the two men appeared to shake hands.
They tested the machine that afternoon. Their images strode above the trees, apparently walking on thin air. Gigantic replicas of Greg stood on a faraway mountain top and shouted with a thunderous voice. Smaller images, no more than two inches high, shinnied up a table leg.
Satisfied, they shut off the machine.
"That's one of the possibilities you mentioned," suggested Russ.
Greg nodded grimly.
An autumn gale pelted the windows with driving rain, and a wild, wet wind howled through the pines outside. The fire was leaping and flaring in the fireplace.
Deep in his chair, Russ stared into the flame and puffed at his pipe.
"The factory wants more money on the spaceship," said Greg from the other chair. "I had to put up some more shares as collateral on a new loan."
"Market still going down?" asked Russ.
"Not the market," replied Greg. "My stocks. All of them hit new lows today."
Russ dragged at the pipe thoughtfully. "I've been thinking about that stock business, Greg."
"So have I, but it doesn't seem to do much good."
"Look," said Russ slowly, "what planets have exchanges?"
"All of them except Mercury. The Jovian exchange is at Ranthoor. There's even one out at Pluto. Just mining and chemical shares listed, though."
Russ did not reply. Smoke curled up from his pipe. He was staring into the fire.
"Why do you ask?" Greg wanted to know.
"Just something stirring around in my mind. I was wondering where Chambers does most of his trading."
"Ranthoor now," said Greg. "Used to do it on Venus. The listing is larger there. But since he took over the Jovian confederacy, he switched his business to it. The transaction tax is lower. He saw to that."
"And the same shares are listed on the Callisto market as on the New York boards?"
"Naturally," said Greg, "only not as many."
Russ watched the smoke from his pipe. "How long does it take light to travel from Callisto to Earth?"
"Why, about 45 minutes, I guess. Somewhere around there." Greg sat upright. "Say, what's light got to do with this?"
"A lot," said Russ. "All commerce is based on the assumption that light is instantaneous, but it isn't. All business, anywhere throughout the Solar System, is based on Greenwich time. When a noon signal sent out from Earth reaches Mars, it's noon there, but as a matter of fact, it is actually 15 minutes or so past noon. When the same signal reaches Callisto, the correct time for the chronometer used in commerce would be noon when it is really a quarter to one. That system simplifies things. Does away with varying times. And it has worked all right so far because there has been, up to now, nothing that could go faster than light. No news can travel through space, no message, no signal can be sent at any speed greater than that. So everything has been fine."
Greg had come out of the chair, was standing on his feet, the glow of the blaze throwing his athletic figure into bold relief. That calm exterior had been stripped from him now. He was excited.
"I see what you are getting at! We have something that is almost instantaneous!"
"Almost," said Russ. "Not quite. There's a time lag somewhere. But it isn't noticeable except over vast distances."
"But it would beat ordinary light signals to Callisto. It would beat them there by almost 45 minutes."
"Almost," Russ agreed. "Maybe a split second less."