Rocket Ship Galileo (14 page)

This face of the moon, anyway—he wondered what the other face was like, the face the earth has never seen.

The dazzle of the moon was beginning to hurt his eyes; he looked up and rested them on the deep, black velvet of space, blacker by contrast with the sprinkle of stars.

There were few of the really bright stars in the region toward which the
Galileo
was heading. Aldebaran blazed forth, high and aft, across the port from the moon. The right-hand frame of the port slashed through the Milky Way and a small portion of that incredible river of stars was thereby left visible to him. He picked out the modest lights of Aries, and near mighty Aldebaran hung the ghostly, fairy Pleiades, but dead ahead, straight up, were only faint stars and a black and lonely waste.

He lay back, staring into this remote and solitary depth, vast and remote beyond human comprehension, until he was fascinated by it, drawn into it. He seemed to have left the warmth and safety of the ship and to be plunging deep into the silent blackness ahead.

He blinked his eyes and shivered, and for the first time felt himself wishing that he had never left the safe and customary and friendly scenes of home. He wanted his basement lab, his mother’s little shop, and the humdrum talk of ordinary people, people who stayed home and did not worry about the outer universe.

Still, the black depths fascinated him. He fingered the drive control under his right hand. He had only to unlock it, twist it all the way to the right, and they would plunge ahead, nailed down by unthinkable acceleration, and speed on past the moon, too early for their date in space with her. On past the moon, away from the sun and the earth behind them, on an on and out and out, until the thorium burned itself cold or until the zinc had boiled away, but not to stop even then, but to continue forever into the weary years and the bottomless depths.

He blinked his eyes and then closed them tight, and gripped both arms of the chair.

THE METHOD OF SCIENCE

• 10 •

“
ARE YOU ASLEEP
?”
THE VOICE
in his ear made Art jump; he had still had his eyes closed—it startled him. But it was only Doc, climbing up behind him.

“Oh! Good morning, Doc. Gee, I’m glad to see you. This place was beginning to give me the jim-jams.”

“Good morning to you, if it is morning. I suppose it is morning, somewhere.” He glanced at his watch. “I’m not surprised that you got the willies, up here by yourself. How would you like to make this trip by yourself?”

“Not me.”

“Not me, either. The moon will be just about as lonely but it will feel better to have some solid ground underfoot. But I don’t suppose this trip will be really popular until the moon has some nice, noisy night clubs and a bowling alley or two.” He settled himself down in his chair.

“That’s not very likely, is it?”

“Why not? The moon is bound to be a tourists’ stop some day—and have you ever noticed how, when tourists get somewhere new, the first thing they do is to look up the same kind of entertainments they could find just as easily at home?”

Art nodded wisely, while tucking the notion away in his mind. His own experience with tourists and travel was slight—until now! “Say, Uncle, do you suppose I could get a decent picture of the moon through the port?”

Cargraves squinted up at it. “Might. But why waste film? They get better pictures of it from the earth. Wait until we go into a free orbit and swing ship. Then you can get some really unique pics—the earth from space. Or wait until we swing around the moon.”

“That’s what I really want! Pictures of the other side of the moon.”

“That’s what I thought.” Cargraves paused a moment and then added, “But how do you know you can get any?”

“But… Oh, I see what you mean. It’ll be dark on that side.”

“That’s not exactly what I meant, although that figures in, too, since the moon will be only about three days past ‘new moon,’ ‘new moon,’ that is, for the other side. We’ll try to time it to get all the pics you want on the trip back. But that isn’t what I mean: how do you know there is any back side to the moon? You’ve never seen it. Neither has any one else, for that matter.”

“But—there has to—I mean, you can see…”

“Did I hear you say there wasn’t any other side to the moon, Doc?” It was Ross, whose head had suddenly appeared beside Cargraves.

“Good morning, Ross. No, I did not say, there was no other side to the moon. I had asked Art to tell me what leads him to think there
is
one.”

Ross smiled. “Don’t let him pull your leg, Art. He’s just trying to rib you.”

Cargraves grinned wickedly. “Okay, Aristotle, you picked it. Suppose you try to prove to me that there is a far side to the moon.”

“It stands to reason.”

“What sort of reason? Have you ever been there? Ever seen it?”

“No, but—”

“Ever met anybody who’s ever seen it? Ever read any accounts by anybody who claimed to have seen it?”

“No, I haven’t, but I’m sure there is one.”

“Why?”

“Because I can see the front of it.”

“What does that prove? Isn’t your experience, up to now, limited to things you’ve seen on earth? For that matter I can name a thing you’ve seen on earth that hasn’t any back side.”

“Huh? What sort of a thing? What are you guys talking about?” It was Morrie this time, climbing up on the other side.

Art said, “Hi, Morrie. Want your seat?”

“No, thanks. I’ll just squat here for the time being.” He settled himself, feet dangling. “What’s the argument?”

“Doc,” Ross answered, “is trying to prove there isn’t any other side to the moon.”

“No, no, no,” Cargraves hastily denied. “And repeat ‘no.’ I was trying to get you to prove your assertion that there was one. I was saying that there was a phenomenon even on earth which hasn’t any back side, to nail down Ross’s argument from experience with other matters—even allowing that earth experience necessarily applies to the moon, which I don’t.”

“Whoops! Slow up! Take the last one first. Don’t natural laws apply anywhere in the universe?”

“Pure assumption, unproved.”

“But astronomers make predictions, eclipses and such, based on that assumption—and they work out.”

“You’ve got it backwards. The Chinese were predicting eclipses long before the theory of the invariability of natural law was popular. Anyhow, at the best, we notice certain limited similarities between events in the sky and events on earth. Which has nothing to do with the question of a back side of the moon which we’ve never seen and may not be there.”

“But we’ve seen a lot of it,” Morrie pointed out.

“I get you,” Cargraves agreed. “Between librations and such—the eccentricity of the moon’s orbit and its tilt, we get to peek a little way around the edges from time to time and see about 6o per cent of its surface—
if
the surface is globular. But I’m talking about that missing 40 per cent that we’ve never seen.”

“Oh,” said Ross, “you mean the side we can’t see might just be sliced off, like an apple with a piece out of it. Well, you may be right, but I’ll bet you six chocolate malts, payable when we get back, that you’re all wet.”

“Nope,” Cargraves answered, “this is a scientific discussion and betting is inappropriate. Besides, I might lose. But I did not mean anything of the slice-out-of-an-apple sort. I meant just what I said: no back side at all. The possibility that when we swing around the moon to look at the other side, we won’t find anything at all, nothing, just empty space—that when we try to look at the moon from behind it, there won’t be any moon to be seen—not from that position. I’m not asserting that that is what we will find; I’m asking you to
prove
that we will find anything.”

“Wait a minute,” Morrie put in, as Art glanced wildly at the moon as if to assure himself that it was still there—it was! “You mentioned something of that sort on earth—a thing with no back. What was it? I’m from Missouri.”

“A rainbow. You can see it from just one side, the side that faces the sun. The other side does not exist.”

“But you can’t get behind it.”

“Then try it with a garden spray some sunny day. Walk around it. When you get behind it, it ain’t there.”

“Yes, but Doc,” Ross objected, “you’re just quibbling. The cases aren’t parallel. A rainbow is just light waves; the moon is something substantial.”

“That’s what I’m trying to get you to prove, and you haven’t proved it yet. How do you know the moon is substantial? All you have ever seen of it is just light waves, as with the rainbow.”

Ross thought about this. “Okay, I guess I see what you’re getting at. But we
do
know that the moon is substantial; they bounced radar off it, as far back as ’46.”

“Just light waves again, Ross. Infra-red light, or ultra-shortwave radio, but the same spectrum. Come again.”

“Yes, but they
bounced
.”

“You are drawing an analogy from earth conditions again. I repeat, we know nothing of moon conditions except through the insubstantial waves of the electromagnetic spectrum.”

“How about tides?”

“Tides exist, certainly. We have seen them, wet our feet in them. But that proves nothing about the moon. The theory that the moon causes the tides is a sheer convenience, pure theory. We change theories as often as we change our underwear. Next year it may be simpler to assume that the tides cause the moon. Got any other ideas?”

Ross took a deep breath. “You’re trying to beat me down with words. All right, so I haven’t seen the other side of the moon. So I’ve never felt the moon, or taken a bite out of it. By the way, you can hang on to the theory that the moon is made of green cheese with that line of argument.”

“Not quite,” said Cargraves. “There is some data on that, for what it’s worth. An astronomer fellow made a spectrograph of green cheese and compared it with a spectrograph of the moon. No resemblance.”

Art chortled. “He didn’t, really?”

“Fact. You can look it up.”

Ross shrugged. “That’s no better than the radar data,” he said correctly. “But to get on with my proof. Granted that there is a front side to the moon, whatever it’s nature, just as long as it isn’t so insubstantial that it won’t even reflect radar, then there has to be some sort of a back, flat, round, square, or wiggly. That’s a matter of certain mathematical deduction.”

Morrie snorted.

Cargraves limited himself to a slight smile. “Now, Ross. Think it over. What is the content of mathematics?”

“The content of mathe—” He collapsed suddenly. “Oh…I guess I finally get it. Mathematics doesn’t have any content. If we found there wasn’t any other side, then we would just have to invent a new mathematics.”

“That’s the idea. Fact of the matter is, we won’t
know
that there is another side to the moon until we get there. I was just trying to show you,” he went on, “just how insubstantial a ‘common sense’ idea can be when you pin it down. Neither ‘common sense’ nor ‘logic’ can
prove
anything. Proof comes from experiment, or to put it another way, from experience, and from nothing else. Short lecture on the scientific method—you can count it as thirty minutes on today’s study time. Anybody else want breakfast but me? Or has the low weight made you queasy?” He started to climb out of his chair.

Ross was very thoughtful while they made preparations for breakfast. This was to be a proper meal, prepared from their limited supply of non-canned foods. The
Galileo
had been fitted with a galley of sorts, principally a hot plate and a small refrigerator. Dishes and knives, forks, and spoons could be washed, sparingly, with the water which accumulated in the dump of the air-conditioner, and then sterilized on the hot plate. The ship had everything necessary to life, even a cramped but indispensable washroom. But every auxiliary article, such as dishes, was made of zinc—reserve mass for the hungry jet.

They sat, or rather squatted, down to a meal of real milk, cereal, boiled eggs, rolls, jam, and coffee. Cargraves sighed contentedly when it had been tucked away. “We won’t get many like that,” he commented, as he filled his pipe. “Space travel isn’t all it’s cracked up to be, not yet.”

“Mind the pipe, Skipper!” Morrie warned.

Cargraves looked startled. “I forgot,” he admitted guiltily. He stared longingly at the pipe. “Say, Ross,” he inquired, “do you think the air-conditioner would clean it out fast enough?”

“Go ahead. Try it,” Ross urged him. “One pipeful won’t kill us. But say, Doc—”

“Yes?”

“Well, uh, look—don’t you really
believe
there is another side to the moon?”

“Huh? Still on that, eh? Of course I do.”

“But—”

“But it’s just my opinion. I believe it because all my assumptions, beliefs, prejudices, theories, superstitions, and so forth, tend that way. It’s part of the pattern of fictions I live by, but that doesn’t prove it’s right. So if it turns out to be wrong I hope I am sufficiently emotionally braced not to blow my top.”

“Which brings us right back to study time,” he went on. “You’ve all got thirty minutes credit, which gives you an hour and a half to go. Better get busy.”