Part 2
"If they did, which I don't believe they will, they would either explode the entire ship, and incidentally make the Earth at least stagger in its orbit, or fuse it instantaneously and so destroy themselves. I might add that we would not survive the calamity."
"No, I rather guessed that. But, Steve, here in the utter cold and utter vacuum of space I should think that it would be hard to heat the ship. How do you do it?"
"The first thing to do in any explanation is to point out that space is neither empty nor cold. In the second place, a vacuum couldn't be either hot or cold. Temperature is a condition of matter, and if there is no matter, there can be no temperature. But space is quite full--about one atom per cubic inch. There is so much matter between us and the fixed stars that we can actually detect the spectrum of space superposed on the spectrum of the star. The light that the stars send us across the intervening spaces comes to us laden with a message of the contents of space--and tells of millions of tons of calcium and sodium. Even the tiny volume of our solar system contains in its free space about 125,000,000,000 grams of matter. That doesn't mean much to an astronomer--but when you remember that every gram of that can furnish as much energy as 10,000,000,000 grams of coal, we see that it isn't so little! And as space does have matter, it can have a temperature, and does. It has a temperature of about 15,000 degrees. Most of the atoms of that space have escaped from the surface of stars and have a temperature about the same as that of the surface of the stars. So you see that space utterly cold--is hotter than anything on Earth! The only difficulty is that it takes a whale of a lot of space to contain enough atoms to weigh a gram, and so the average concentration of heat is so low that we can say that space is cold. Similarly a block of ice may contain far more heat than a piece of red-hot iron. Nevertheless; I would prefer to sit on the ice."
"Quite so, I see your point, and I believe I'd prefer the ice myself. But that's interesting! Space isn't empty, it's not cold, in fact it is unusually hot!"
"Now we've started this let's finish it, Dave. It is hot, but not unusually hot--if anything it is unusually cold! The usual, or average temperature of all the matter in the universe is about one million degrees, so space at 15,000 is really far below the average, and so we can say that it is unusually cold. The temperature of the interior of the stars is uniformly forty million degrees, which brings the average up. But it is the unthinkably great quantities of matter in interstellar space that brings the average down. Remember that the nearest star is four and a half light years from us, and between the stars there is such a vast space in which the matter is thinly distributed that the few pinpoint concentrations of matter have to be extremely hot if they are to bring the average up any appreciable amount. But here and there in this vast space there are a few tiny bits of matter that have cooled down to terrifically frigid temperatures--temperatures within a few degrees of absolute zero, only two or three hundred degrees above; spots of matter so cold that hydrogen and oxygen can unite; so cold that this compound can even condense to a liquid; so cold that life can exist. We call those pinpoints planets.
"In the interstellar range of temperatures we have everywhere from absolute zero to forty million above. Life can exist between the temperatures absolute, of about two hundred and three hundred and twenty--a range of one hundred degrees in a range of forty million. That means that the temperature of this planet must be maintained with an allowable inaccuracy of one part in four hundred thousand! Do you see what the chances of a planet's having a 'habitable' temperature are?
"But we are near my laboratory now, Dave, and I want to introduce you to Wright, my laboratory assistant, a brilliant student, and an uncannily clever artisan. He made Bartholemew, as I call the mathematics machine, and most of the parts of this ship. He had heat rays to work with, and had iridium metal as his material, and plenty of any element. He had a fine time working out the best alloy, and the best treatment. The shell of the car is made of an alloy of tungsten, iridium and cobalt. It is exceedingly tough, very strong, and very hard. It will scratch glass, is stronger than steel, and is as ductile and malleable as copper--if you have sufficient force. Iridium used to sell for about 250 dollars an ounce, but these powers allow me to transmute it, which renders it cheap for me. After this, sodium metal will be cheaper than sodium compounds!"
"I wish that that trip had not been so short, Steve. There were a lot of things I wanted to ask you. Where are we now? I don't seem to recognize this country."
"We are over Arizona--see there is the laboratory now--off there."
"What, Arizona! How fast were we going?"
"We were going slowly, considering we were in space, but considering our proximity to the Earth we are going rapidly. The actual speed is difficult to determine--remember we had cut loose all ties of gravity, and I had to follow the Earth in its orbit, and the whole solar system along through space. From here to New York City is about three thousand miles, and as we made the trip in just under one hundred minutes, we traveled at a speed of thirty miles a minute, or half a mile a second."
"Well, the airplane speed record was about four hundred and twenty, wasn't it--I mean an hour--you have to specify now! You set a new record, I guess!"
* * * * *
They were slanting down through the atmosphere toward the distant low building that had seen the construction of that first of Earth's space cruisers. The long gentle glide slowly flattened out and the car at last glided slowly, gently through the open hangar doors. Wright was there to greet them, but Waterson called out that he would stay in the ship a few minutes to show Gale around.
"Steve, you sure picked a desolate place to work in. Why did you go way out here?"
"For two reasons. First I wanted a place that was quiet; and second I wanted a place where I could safely work with atomic energy--where explosions, premeditated or accidental, would not blow up an entire city. Did you notice that crater off to one side as we came in? That is where I tried out my first bullet. I hadn't gotten a small enough charge in it. I had nearly a milligram--a hundredth of a drop of water. But come, I guess you saw the pilot room. I'll show you how to run the ship tomorrow."
He led the way to the rear end of the pilot room, where a small door opened in the smooth, windowless metal partition. It too gleamed with that strangely iridescent beauty of metallic iridium.
"This bunk room should appeal to an apartment house addict. I had about eleven feet I could use to make it, and it is just a bit crowded."
Considering Waterson's six-feet-two, a room eleven feet long, ten feet high, and about as wide, would certainly be crowded if there was anything or anyone else in the room. As the bunk room was also dining room, gallery, and chart room, it was decidedly crowded. One thing that particularly interested Gale was a small screen on which were a series of small lights, projected from the rear.
"What is that, Steve?" he inquired.
"That is my chart. It is the only kind of a chart you could well expect on board a space ship. The lights are really moving and maintain the relative positions of the planets. I think we will go to Mars first, because it is now as close as it will be for some time. I want to go to Venus soon, but that is on the other side of the sun. I will find that there are detours even in space when I go there!"
"That's quite a chart! I suppose you have more accurate ones too?"
"No, I have no need of more accurate ones. I start for my objective, and it is so big I can't miss it!"
"That's true too! But I haven't seen any apparatus for taking care of your air. I suspect that door over there hides something."
"It does. It leads to the store room and the apparatus room. There are all the tools I carry, the air purifier and water renewer. Remember that the break-up of the atomic energy gives me unlimited amounts of electricity, so I have all the electric power I can use. I find that there is a way to electrolyse carbon dioxide to carbon and oxygen. In this manner I recover the oxygen for the air--at least part of the necessary oxygen--and at the same time remove the menace of the CO_{2}. There is considerable oxygen fixed as H_{2}O, however, so I installed an electrolyser to take care of that. The moisture of the air is in this way kept down to a comfortable maximum. The same apparatus is useful for reducing the water. All the water I have I must carry in tanks, which require space. I am able to make them considerably smaller by taking the water, passing it through this electrolyser, reducing it to hydrogen and oxygen, burning them to water again, and thus getting pure H_{2}O. The one difficulty is in getting rid of the heat. Remember that all the heat I lose I must lose by radiation. But the sun is radiating to me. I receive heat at exactly the same rate the Earth does and I have no protective atmosphere, so the tendency is to reach a super-tropical temperature. The easiest solution of this problem is to go with the ship at such an angle to the sun that the shadow of the exposed surface shades the greater portion of the ship, then by adjusting the angle of the ship, I can adjust the ratio of radiating to receiving area to any value I wish, and get almost any temperature I need."
"That is an idea, I never heard of electrolysing carbon dioxide, though. Tell me--how do you do it?"
"That is a process I developed. It requires considerable explaining. However, I am doubtful whether it wouldn't have been easier to convert the stuff directly to oxygen by transmutation."
"Steve, I notice you have plenty of light, but why not have windows?"
* * * * *
"I have no windows except in the main pilot room. The trouble with windows is that they reduce the strength of the shell. Also, as this is a sleeping room, and there will be no night in space, why not have it this way? I need considerable strength in the walls of the ship, because the accelerations that I use in starting and turning and stopping are really rather a strain on any material. The outer wall is a six-inch iridio-tungsten alloy shell, with two openings in it, the window, and the door. The rest is absolutely seamless, one solid casting. The window is so designed, in connection with the placement of the ray projectors that it doesn't weaken the shell. There is no frame work, but the two partitions across the ship are each six inches thick, and act as braces. The inner wall is a thin one-inch layer of metal, supported by the outer shell, and separated from it by small braces about two inches high. This intervening space has been evacuated by the simple process of going out into space and opening a valve, then closing it before returning to Earth."
"That one-inch layer of metal of yours is bothering me. There is something strange about it, and all the trim and mouldings in here. The green I suppose is to relieve eye strain, but it is not the color itself that seems strange. It is the impression I have that the metal itself is of that beautiful leaf green shade, and that it is the metal in the chairs, table, and racks that gives them that color."
"Quite right Dave, it is."
"But Steve, I thought that there were no more elements to be discovered. In the collection at the Museum in New York they had all ninety-two, and I saw no colored metals."
"In the first place, remember I told you there really were more than ninety-two elements, if we treat the isotopes as elements, and I don't believe they had all the ninety-two there, for there are several elements that disintegrate inside of a few days. They couldn't keep those. But these metals are compounds."
"Compounds! Do you mean alloys?"
"No, chemical compounds, just as truly as salt or sulphuric acid. They are related to tetra ethyl stibine, Sb(C_{2}H_{5})_{4}, which is a compound that acts like a metal physically and chemically. It is too soft to be any good, but there are hundreds of these organic compounds of carbon. There are red ones, green ones, blue ones, and a thousand different ones, soft, brittle, liquid, solid; some are even gaseous."
"Colored metals! What a boon to artists! Think what fun they will have working in that stuff!"
"Yes, but it is also useful for decorative purposes, although the large molecule makes it too soft to be used as a wearing surface."
"Well Steve, you sure have a mighty fine little ship! What do you call it? You said that you called the mathematics machine 'Bartholemew.' What do you call this?"
"As yet it has not been named. I wanted you to suggest some name for it."
"That's a sudden order, Steve. What have you thought of?"
"Well, I thought of calling it fluorine, for the chemical element which is so active that it can not be displaced by any other, but will, on the other hand, force any other non-metal out of its compound. Then I thought of Niña, the name of Columbus' ship which first touched a new world, and Wright reminded me that Eric, the Red's son Lief landed here in about 1000 and suggested Eric as a name."
"Well, that's a good assortment. Why pick on me?"
"We thought you ought to be good at inventing names, since you had written several books."
"That is a fine excuse! I get mine from old magazines! But I might suggest 'The Electron.' It sounds well, and I remember that you said that you charged it negatively to cut out the gravity of the Earth and an electron--or is it a proton that has a negative charge?"
"'The Electron'--sounds good--and the idea is good. An electron has a negative charge. Wright also suggested the 'Terrestrian,' as it would be the first ship of Earth to visit other worlds. It is between 'Electron' and 'Terrestrian' now. Which do you like better?"
"I prefer 'Terrestrian.' It has more meaning."
"Well, we'll tell Wright about it. In the mean time, come in to the laboratory and meet Bartholemew."
* * * * *
Bartholemew was at the moment engaged in tracing a very complicated curve, the integral of a half dozen or so other curves. Wright was carefully watching the thin line left by the pencil. There was a low steady humming coming from the machine, and a bank of small transformers on the other side of the room connected to it. Wright turned off the machine as they entered, and after greeting Waterson, and meeting Gale, proceeded at once with an enthusiastic description of the machine. He was obviously proud of the machine, and of the man who had developed it. The entire machine had been enclosed in a metal case when Gale entered, but now Wright opened this, and Gale was decidedly surprised to see the interior. He really had had no reason to form any opinion of the machine, but he had expected a maze of gears, shafts, levers, chains and every sort of mechanical apparatus. Somehow the mention of a machine for doing mathematics conveyed to him that impression. The actual machine seemed quite simple--merely a small cable leading from the separate "graph interpreters," as Wright called them, to the central integrater, and hence a small motor carried the integrated result into practice and put it on paper.
This machine made possible a type of mathematics hitherto unknown. This new calculus was to the previous integration what integration was to addition. Integration is an infinite summation of very small terms, and this new mathematics was an integration in an infinite number of dimensions. The beginner first learns to integrate in two dimensions. Then come three. Einstein had carried his mathematics to four. The machine seemed to work in an infinite number of dimensions, but the conditions of the problem really chose the four out of infinity that were under discussion. An infinite number of dimensions has no physical meaning. It might be put this way, Wright said: there are an infinite number of solutions to the equation x=2+y, and as such it has no meaning. But if for example you say also that 2y=x, then auto-mathematically you choose two of an infinite number of values that fit the problem in hand. A man might have done all this machine did, had he lived long enough and been patient enough. This machine could do in an hour a problem that would have taken a man a lifetime. Thus it had been able to develop the true mathematical picture of the atom.
* * * * *
Over the supper table that night they had a final discussion as to the name of the ship. It was decided that the name should be "Terrestrian," and plans were made to christen it in as scientific a manner as possible. Considering that the shell was made of iridium, and therefore highly inert to chemical action, they decided on a bottle of aqua regia which dissolves gold and platinum, and does not attack iridium. A bottle was prepared, and they were ready for the christening in the morning. Just as they decided to call the day done, the telephone rang. It was Dr. Wilkins of Mt. Wilson calling Waterson. The conversation was rather lengthy, and Wright, who had answered, told Gale that Dr. Wilkins had called before, about two months ago, on a question in astro-physics, and Waterson had been able to give the answer. This time however, Dr. Wilkins, it seemed, was greatly agitated. Just then Waterson returned.
"Gale, it seems we chose our name well. Also I am lucky in having you here. I must go to Mt. Wilson at once, I'll be back about dawn, and I'll tell you two all about it then. I've got to hurry. So long."
A moment later the two men heard the hum of the motor as the hangar doors were opened. Another moment and the entire countryside was flooded with a blaze of bluish white light, that illuminated the desolate dry desert for miles, and for all those weary miles it was an unending, rolling surface of sand. In the glow of sudden light, great strange shadows which started up by the buildings gave weird effects on the sand, but with it all there was a rugged and compelling beauty to the little world which the light had cut from the darkness. There was a sudden whistle of air, and the light faded as the car shot off toward Mt. Wilson.
"What a mass of sand there is around here! It would seem almost like a dried up ocean bed," said Gale.
"I suppose there is a lot of sand in the world--there should be though, it is the direct compound of the two most abundant elements on Earth, silicon and oxygen."
"Wright, I've often wondered why it is that oxygen, which combines with almost anything, should be found free in nature. Why is it?"
"I don't know, I'm sure. At that I suppose one reason is that there is so much of it. Just a very small fraction less than half of the Earth's surface layers is oxygen. It forms over forty-nine per cent of it to a depth of ten miles at least. It is the second most active element on Earth--in the universe for that matter, and of the active elements there is only one with which it can't combine, namely, fluorine. Of course it can't combine with the inert gases, so I say the active elements. I suppose it is left free principally because there was nothing else to do. Apparently there weren't enough partners to go around. At that it did a mighty good job of it! Forty-seven per cent. of the solid crust is oxygen, 85% of the water is oxygen, and 20% of the air is free oxygen. Well, let's not look so favorable a gift horse in the mouth. If it hadn't been left free, where would we be?"
The discussion soon died down and the men retired for the night, each wondering what it was that had called Waterson away so suddenly, and each determined to be on hand when he returned in the morning.
The coming of the light of dawn had, perforce, put an end to the activities at Mt. Wilson, so it was shortly after sunrise that the two men heard the hangar doors open. And it was very shortly after sunrise that they had dressed and gone down to greet Waterson. The worried look on his face told a great deal, for both men knew him well, and when Waterson looked worried there was something of tremendous import under way.
"Hello. Had a good night Dave? I have something that is going to interest you--and two and a half billion other human beings. They have discovered something at the Mt. Wilson observatory that is going to change our plans quite a bit. We had intended going to other planets to visit the inhabitants, but we won't have to go. They are coming to us; furthermore, twenty ships are coming, and I have an idea they are good sized ships. But Wright, I think you had better start breakfast. We can discuss it at the table. I'm going to wash, and if you will help Wright, Dave, I think we will be at work pretty soon." Waterson left the room, and the two men looked at his retreating figure with astonishment and wonder. An announcement that our planet was to be invaded from space is a bit hard to take in all at once, and particularly when it is given in the matter of fact way that Waterson had presented it, for he had known it now for over ten hours, and had been working on it during all that time.
* * * * *
At the table the explanation was resumed.