"What have they been doing with the star?" Morey snorted. "Hiding it behind a sun-shade?"
Arcot grinned. "Yes. A shade of old age. You know a sun can"t radiate forever; eventually they die. And a dead sun would be quite black, I"m sure."
"And the planets that circle about them are apt to become a wee bit cool too, you know."
"Agreed," said Arcot, "and we wouldn"t be able to do much about it. But give these beings credit for a little higher order of intelligence. We saw machines in that s.p.a.ce ship that certainly are beyond us! They are undoubtedly heating their planets with the same source of energy with which they are running their ships.
"I believe I have confirmation of that statement in two things. They are absolutely colorless; they don"t even have an opaque white skin. Any living creature exposed to the rays of a sun, which is certain to emit some chemical rays, is subject to coloration as a protection against those rays. The whites, who have always lived where sunlight is weakest, have developed a skin only slightly opaque. The Orientals, who live in more tropical countries, where less clothes and more sun is the motto, have slightly darker skins. In the extreme tropics Nature has found it necessary to use a regular blanket of color to stop the rays. Now extrapolating the other way, were there no such rays, the people would become a pigmentless race. Since most proteins are rather translucent, at least when wet, they would appear much as these beings do. Remember, there are very few colored proteins. Hemoglobin, such as in our blood, and hemocyanin, like that in the blue blood of the Venerians, are practically unique in that respect. For hydrogen absorption, I imagine the blood of these creatures contains a fair proportion of some highly saturated compound, which readily takes on the element, and gives it up later.
"But we can kick this around some more in the lab."
Before starting for New York, Arcot had convinced the officer in charge that it would be wise to destroy the more complete of the invaders"
ships at once, lest one of them manage to escape. The fact that none of them had any rays in operation was easily explained; they would have been destroyed by the Patrol if they had made any show of weapons. But they might be getting some ready, to be used in possible escape attempts. The scientists were through with their preliminary investigations. And the dismembered sections would remain for study, anyway.
The ships had finally been rayed apart, and when the three had left, their burning atmosphere had been sending mighty tongues of flame a mile or more into the air. The light gas of the alien atmosphere tended to rise in a great globular cloud, a ball that quickly burned itself out.
It had not taken long for the last of the machines to disintegrate under the rays. There would be no more trouble from them, at any rate!
Now Morey asked Arcot if he thought that they had learned all they could from the ships; would it not have been wiser to save them, and investigate more fully later, taking a chance on stopping any sudden attack by surviving marauders by keeping a patrol of Air Guards there.
To which Arcot replied, "I thought quite a bit before I suggested their destruction, and I conferred for a few moments with Forsyth, who"s just about tops in biology and bacteriology. He said that they had by no means learned as much as they wished to, but they"d been forced to leave in any event. Remember that pure hydrogen, the atmosphere we were actually living in while on the ship, is quite as inert as pure oxygen--when alone. But the two get very rough when mixed together. The longer those ships lay there the more dangerously explosive they became.
If we hadn"t destroyed them, they would have wrecked themselves. I still think we followed the only logical course.
"Dr. Forsyth mentioned the danger of disease. There"s a remote possibility that we might be susceptible to their germs. I don"t believe we would be, for our chemical const.i.tution is so vastly different. For instance, the Venerians and Terrestrians can visit each other with perfect freedom. The Venerians have diseases, and so do we, of course; but there are things in the blood of Venerians that are absolutely deadly to any Terrestrian organism. We have a similar deadly effect on Venerian germs. It isn"t immunity--it"s simply that our respective const.i.tutions are so different that we don"t need immunity. Similarly, Forsyth thinks we would be completely resistant to all diseases brought by the invaders. However, it"s safer to remove the danger, if any, first, and check afterward."
The three men sped rapidly back to New York, flying nearly sixty miles above the surface of the Earth, where there would be no interfering traffic, till at length they were above the big city, and dropping swiftly in a vertical traffic lane.
Shortly thereafter they settled lightly in the landing cradle at the Arcot Laboratories. Arcot"s father, and Morey"s, were there, anxiously awaiting their return. The elder Arcot had for many years held the reputation of being the nation"s greatest physicist, but recently he had lost it--to his son. Morey Senior was the president and chief stockholder in the Transcontinental Air Lines. The Arcots, father and son, had turned all their inventions over to their close friends, the Moreys. For many years the success of the great air lines had been dependent in large part on the inventions of the Arcots; these new discoveries enabled them to keep one step ahead of compet.i.tion, and as they also made the huge transport machines for other companies, they drew tremendous profits from these mechanisms. The mutual interest, which had begun as a purely financial relationship, had long since become a close personal friendship.
As Arcot stepped from his speedster, he called immediately to his father, telling of their find, the light-matter plate.
"I"ll need a handling machine to move it. I"ll be right back." He ran to the elevator and dropped quickly to the heavy machinery lab on the lower floor. In a short time he returned with a tractor-like machine equipped with a small derrick, designed to get its power from the electric mains.
He ran the machine over to the ship. The others looked up as they heard the rumble and hum of its powerful motor. From the crane dangled a strong electro-magnet.
"What"s that for?" asked Wade, pointing to the magnet. "You don"t expect this to be magnetic, do you?"
"Wait and see!" laughed Arcot, maneuvering the handling machine into position. One of the others made contact with the power line, and the crane reached into the ship, lowering the magnet to the plate of crystal. Then Arcot turned the power into the lifting motor. The hum rose swiftly in volume and pitch till the full load began to strain the cables. The motor whined with full power, the cables vibrating under the tension. The machine pulled steadily, until, to Arcot"s surprise, the rear end of the machine rose abruptly from the floor, tipping forward.
"Well--it _was_ magnetic, but how did you know?" asked the surprised Wade. Since the ship was made of the Venerian metal, coronium, which was only slightly magnetic, the plate was obviously the magnet"s only load.
"Never mind. I"ll tell you later. Get an I-beam, say about twenty feet long, and see if you can"t help lift that crazy ma.s.s. I think we ought to manage it that way."
And so it proved. With two of them straddling the I-beam, the leverage was great enough to pull the plate out. Running it over to the elevator, they lowered the heavy ma.s.s, disconnected the cable, and rode down to Arcot"s laboratory. Again the I-beam and handling machine were brought into play, and the plate was unloaded from the car. The five men gathered around the amazing souvenir from another world.
"I"m with Wade in wondering how you knew the plate was magnetic, son,"
commented the elder Arcot. "I can accept your explanation that the stuff is a kind of matter made of light, but I know you too well to think it was just a lucky guess. How did you know?"
"It really was pretty much of a guess, Dad, though there was some logic behind the thought. You ought to be able to trace down the idea! How about you, Morey?" Arcot smiled at his friend.
"I"ve kept discreetly quiet," replied Morey, "feeling that in silence I could not betray my ignorance, but since you ask me, I can guess too. I seem to recall that light is affected by a powerful magnet, and I can imagine that that was the basis for your guess. It has been known for many years, as far back as Clerk Maxwell, that polarized light can be rotated by a powerful magnet."
"That"s it! And now we may as well go over the whole story, and tell Dad and your father all that happened. Perhaps in the telling, we can straighten out our own ideas a bit."
For the next hour the three men talked, each telling his story, and trying to explain the whys and wherefores of what he had seen. In the end all agreed on one point: if they were to fight this enemy, they _must_ have ships that could travel though s.p.a.ce with speed to match that of the invaders, ships with a self-contained source of power.
During a brief lull in the conversation, Morey commented rather sarcastically: "I wonder if Arcot will now kindly explain his famous invisible light, or the lost star?" He was a bit nettled by his own failure to remember that a star could go black. "I can"t see what connection this has with their sudden attack. If they were there, they must have developed when the star was bright, and as a star requires millions of years to cool down, I can"t see how they could suddenly appear in s.p.a.ce."
Before answering, Arcot reached into a drawer of his desk and pulled out an old blackened briar pipe. Methodically he filled it, a thoughtful frown on his face; then carefully lighting it, he leaned back, puffing out a thin column of gray smoke.
"Those creatures must have developed on their planets before the sun cooled." He puffed slowly. "They are, then, a race millions of years old--or so I believe. I can"t give any scientific reason for this feeling; it"s merely a hunch. I just have a feeling that the invaders are old, older than our very planet! This little globe is just about two billion years old. I feel that that race is so very ancient they may well have counted the revolutions of our galaxy as, once every twenty or thirty million years, it swung about its center.
"When I looked at those great machines, and those comparatively little beings as they handled their projectors, they seemed out of place. Why?"
He shrugged. "Again, just a hunch, an impression." He paused again, and the slow smoke drifted upward.
"If I"m granted the premise that a black, dead star is approaching the Solar System, then my theorizing may seem more logical. You agree?" The listeners nodded and Arcot continued. "Well--I had an idea--and when I went downstairs for the handling machine, I called the Lunar Observatory." He couldn"t quite keep a note of triumph out of his voice.
"Gentlemen--some of the planets have been misbehaving! The outermost planets, and even some of those closer to the sun have not been moving as they should. A celestial body of appreciable ma.s.s _is_ approaching the System; though thus far nothing has been seen of the visitor!"
A hubbub of excited comment followed this startling revelation. Arcot quieted them with an upraised hand. "The only reason you and the world at large haven"t heard about this as yet is the fact that the perturbation of the planets is so very slight that the astronomers figured they might have made an error in calculation. They"re rechecking now for mistakes.
"To get back to my visualization--It must have been many millions of years ago that life developed on the planets of the black star, a warm sun then, for it was much younger. It was probably rather dim as suns go even its younger days. Remember, our own sun is well above average in brilliance and heat radiation.
"In those long-gone ages I can imagine a race much like ours developing, differing chemically, in their atmosphere of hydrogen; but the chemical body is not what makes the race, it"s the thought process. They must have developed, and then as their science grew, their sun waned. Dimmer and dimmer it became, until their planets could not maintain life naturally. Then they had to heat them artificially. There is no question as to their source of power; they had to use the energy of matter--so called atomic energy--for no other source would be great enough to do what had to be done. It is probable that their science had developed this long before their great need arose.
"With this must also have come the process of trans.m.u.tation, and the process they use in driving their interstellar cruisers. I am sure those machines are driven by material energy.
"But at last their star was black, a closed star, and their cold, black planets must circle a hot, black sun forever! They were trapped for eternity unless they found a way to escape to some other stellar system.
They could not travel as fast as light, and they could escape only if they found some near-by solar system. Their star was dead--black. Let"s call it Nigra--the Black One--since like every other star it should have a name. Any objection?"
There was none, so Arcot continued:
"Now we come to an impossibly rare coincidence. That two suns in their motion should approach each other is beyond the point of logic. That both suns have a retinue of planets approaches the height of the ridiculous. Yet that is what is happening right now. And the Nigrans--if that"s the correct term--have every intention of taking advantage of the coincidence. Since our sun has been visible to them for a long, long time, and the approaching proximity of the suns evident, they had lots of time to prepare.
"I believe this expedition was just an exploratory one; and if they can send such huge machines and so many of them, for mere exploration, I"m sure they must have quite a fleet to fight with.
"We know little about their weapons. They have that death ray, but it"s not quite as deadly as we might have feared, solely because our ships could outmaneuver them. Next time, logically, they"ll bring with them a fleet of little ships, carried in the bellies of those giants, and they"ll be a real enemy. We"ll have to antic.i.p.ate their moves and build to circ.u.mvent them.
"As for their ray, I believe I have an idea how it works. You"re all familiar with the catalytic effects of light. Hydrogen and chlorine will stand very peacefully in the same jar for a long time, but let a strong light fall on them, and they combine with terrific violence. This is the catalytic effect of a vibration, a wave motion. Then there is such a thing as negative catalysis. In a certain reaction, if a third element or compound is introduced, all reaction is stopped. I believe that"s the principle of the Nigran death ray; it"s a catalyst that simply stops the chemical reactions of a living body, and these are so delicately balanced that the least resistance will upset them."
Arcot halted, and sat puffing furiously for a moment. During his discourse the pipe had died to an ember; with vigorous puffing he tried to restore it. At last he had it going and continued.
"What other weapons they have we cannot say. The secret of invisibility must be very old to them. But we"ll guard against the possibility by equipping our ships against it. The only reason the patrol ships aren"t equipped already is that invisibility is useless with modern criminals; they all know the secret and how to fight it."
Morey interrupted with a question.
"Arcot, it"s obvious that we have to get out into s.p.a.ce to meet the enemy--and we"ll have to have freedom of movement there. How are we going to do it? I was wondering if we could use Wade"s system of storing the atomic hydrogen in solution. That yields about 100,000 calories for every two grams, and since this is a method of storing heat energy, and your molecular motion director is a method of converting heat into mechanical work with 100 per cent efficiency, why not use that? All we need, really, is a method of storing heat energy for use while we"re in s.p.a.ce."
Arcot exhaled slowly before answering, watching the column of smoke vanish into the air.
"I thought of that, and I"ve been trying to think of other, and if possible, better, cheaper, and quicker ways of getting the necessary power.