Farmer in the Sky

6. E = MC ²

I looked up dad after they let us go. It was like finding a needle in a haystack but I kept asking and presently I found him. Molly and he had a room to themselves. Peggy was there and I thought she was rooming with them, which annoyed me some, until I saw that there were only two couches and realized that Peggy must be in a dormitory. It turned out that all the kids over eight were in dormitories.

Dad was busy unclamping their couches and moving them to what was the floor, now that the ship was spinning. He stopped when I came in and we sat around and talked. I told him about Captain's mast. He nodded. "We saw it in the screen. I didn't notice your shining face, however."

I said I hadn't been called on.

"Why not?" Peggy wanted to know.

"How should I know?" I thought about mast for a bit and said, "Say, George, the skipper of a ship in space is just about the last of the absolute monarchs, isn't he?"

Dad considered it and said, "Mmm... no, he's a constitutional monarch. But he's a monarch all right."

"You mean we have to bow down to him and say 'Your Majesty?" Peggy wanted to know.

Molly said, "I don't think that would be advisable, Peg."

"Why not? I think it would be fun."

Molly smiled. "Well, let me know how you make out. I suspect that he will just turn you over his knee and paddle you."

"Oh, he wouldn't dare! I'd scream."

I wasn't so sure. I remembered those four hundred million miles of dirty dishes. I decided that, if the Captain said "Frog," I'd hop.

If Captain Harkness was a monarch, he didn't seem anxious to rule; the first thing he had us do was to hold an election and set up a ship's council. After that we hardly laid eyes on him.

Everybody over eighteen could vote. The rest of us got to vote, too; we were told to setup a junior council—not that it was ever good for anything.

But the senior council, the real council, ran the ship from then on. It even acted as a court and the Captain never handed out punishments again. Dad told me that the Captain reviewed everything that the council did, that he had to, to make it legal—but I never heard of him overruling their decisions.

And you know what the first thing was that that council did—after setting up meal hours and simple things like that? They decided we had to go to school!

The junior council promptly held a meeting and passed a resolution against it, but it didn't mean anything. We had school, just the same.

Peggy was on the junior council. I asked her why she didn't resign if she wasn't going to do anything. I was just teasing—as a matter of fact she put up quite a battle for us.

School wasn't so bad, though. There is very h'ttle to do in space and when you've seen one star you've seen 'em all. And the first thing we had in school was a tour of the ship, which was all right.

We went in groups of twenty and it took all day–"day" by ship's time, I mean. The Mayflower was shaped like a ball with a cone on one side—top shaped. The point of the cone was her jet—although Chief Engineer Ortega, who showed us around, called it her "torch."

If you count the torch end as her stern, then the round end, her bow, was where the control room was located; around it were the Captain's cabin and the staterooms of the officers. The torch and the whole power plant space were cut off from the rest of the ship by a radiation shield that ran right through the ship. From the shield forward to the control room was a big cargo space. It was a cylinder more than a hundred feet in diameter and was split up into holds. We were carrying all sorts of things out to the colony —earth moving machinery, concentrated soil cultures, instruments, I don't know what all.

Wrapped around this central cylinder were the decks for living, "A" deck just inside the skin of the ship, "B" deck under it, and "C" deck just inside that, with "D" deck's ceiling being the outer wall of the cargo space. "D" deck was the mess rooms and galley and recreation rooms and sick bay and such; the three outer decks were bunk rooms and staterooms. "A" deck had steps in it every ten or fifteen feet because it was fitted into the outer curve of the ship; this made the ceilings in it of various heights. The furthest forward and furthest aft on "A" deck were only about six feet between floor and ceiling and some of the smaller kids lived in them, while at the greatest width of the ship the ceilings in "A" deck must have been twelve or thirteen feet high.

From inside the ship it was hard to see how it all fitted together. Not only was it all chopped up, but the artificial gravity we had from spinning the ship made directions confusing—anywhere you stood on a deck it seemed level, but it curved sharply up behind you and in front of you. But you never came to the curved part; if you walked forward it was still level. If you walked far enough you looped the loop and came back to where you started, having walked clear around the ship.

I never would have figured it out if Mr. Ortega hadn't drawn a sketch for us.

Mr. Ortega told us that the ship was spinning three and six-tenths revolutions per minute or two hundred and sixteen complete turns an hour, which was enough to give "B" deck a centrifugal force of one-third g. "B" deck was seventy-five feet out from the axis of the Mayflower; "A" deck where I lived was further out and you weighed maybe a tenth more there, while "C" deck caught about a tenth less. "D" deck was quite a lot less and you could make yourself dizzy if you stood up suddenly in the mess room.

The control room was right on the axis; you could float in it even when the ship was spinning—or so they told me; I never was allowed inside.

Spinning the ship had another odd effect: all around us was "down." I mean to say that the only place you could put a view port was in the floor plates of "A" deck and that's where they were, four of them—big ones, each in its own compartment.

Mr. Ortega took us into one of these view galleries. The view port was a big round quartz plate in the floor, with a guard rail around it.

The first ones into the room went up to the guard rail and then backed away from it quick and two of the girls squealed. I pushed forward and got to the rail and looked down ,...nd I was staring straight into the very bottom of the universe, a million trillion miles away and all of it down.

I didn't shy away—George says I'm more acrobat than acrophobe—but I did sort of grip the railing. Nobody wants to fall that far. The quartz was surface-treated so that it didn't give off reflections and it looked as if there were nothing at all between you and Kingdom Come.

The stars were reeling across the hole from the ship spinning, which made it worse. The Big Dipper came swinging in from the left, passed almost under me, and slid away to the right—and a few seconds later it was back again. I said, "This is where I came in," and gave up my place so that someone else could have a look, but nobody seemed anxious to.

Then we went through the hydroponics plant, but there wasn't anything fancy about that—just enough plants growing to replace the oxygen we used up breathing. Eel grass, it was mostly, but there was a vegetable garden as well. I wondered how they had gotten it going before they had the passengers aboard? Mr. Ortega pointed to a CO₂ fitting in the wall. "We had to subsidize them, of course."

I guess I should have known it; it was simple arithmetic.

The Chief led us back into one of the mess rooms, we sat down, and he told us about the power plant.

He said that there had been three stages in the development of space ships: first was the chemical fuel rocket ship that wasn't very different from the big German war rockets used in the Second World War, except that they were step rockets. "You kids are too young to have seen such rockets," he said, "but they were the biggest space ships ever built. They had to be big because they were terribly inefficient. As you all know, the first rocket to reach the Moon was a four-stage rocket. Its final stage was almost as long as the Mayflower—yetits pay load was less than a ton.

"It is characteristic of space ship development that the ships have gotten smaller instead of bigger. The next development was the atom-powered rocket. It was a great improvement; steps were no longer necessary. That meant that a ship like the Daedalus could take off from Earth without even a catapult, much less step rockets, and cruise to the Moon or even to Mars. But such ships still had the shortcomings of rockets; they depended on an atomic power plant to heat up reaction mass and push it out a jet, just as their predecessors depended on chemical fuel for the same purpose.

"The latest development is the mass-conversion ship, such as the Mayflower, and it may be the final development—a mass-conversion ship is theoretically capable of approaching the speed of light. Take this trip: we accelerated at one gravity for about four hours and twenty minutes which brought us up to more than ninety miles a second. If we had held that drive for a trifle less than a year, we would approach the speed of light.

"A mass-conversion ship has plenty of power to do just that. At one hundred per cent efficiency, it would use up about one per cent of her mass as energy and another one per cent as reaction mass. That's what the Star Rover is going to do when it is finished."

One of the younger kids was waving his hand. "Mister Chief Engineer?"

"Yes, son?"

"Suppose it goes on a few weeks longer and passes the speed of light?"

Mr. Ortega shook his head. "It can't."

"Why not, sir?"

"Eh, how far have you gone in mathematics, sonny?"

"Just through grammer school calculus," the kid answered.

'Tm afraid there is no use in trying to explain it, then. Just take it from me that the big brains are sure it can't be done."

I had worried about that very point more than once. Why can't you go faster than light? I know all that old double-talk about how the Einstein equations show that a speed faster than light is a meaningless quantity, like the weight of a song or the color of a sound, because it involves the square root of minus one—but all of that is just theory and if the course we had in history of science means anything at all, it means that scientists change their theories about as often as a snake changes his skin. I stuck up my hand.

"Okay," he says. "You with the cowlick. Speak up."

"Mr. Ortega, admitting that you can't pass the speed of light, what would happen if the Star Rover got up close to the speed of light—and then the Captain suddenly stepped the drive up to about six g and held it there?"

"Why, it would— No, let's put it this way—" He broke off and grinned; it made him look real young. "See here, kid, don't ask me questions like that. I'm an engineer with hairy ears, not a mathematical physicist." He looked thoughtful and added, "Truthfully, I don't know what would happen, but I would sure give a pretty to find out. Maybe we would find out what the square root of minus one looks like— from the inside."

He went on briskly, "Let's go on about the Mayflower. You probably know that when the original Star Rover failed to come back, the Mayflower was designed to be the Star Rover II, but the design was obsolete before they ever started putting her together. So they shifted the name over to the new intersteller ship, the Star Rover III, renamed this one the Mayflower and grabbed her for the colonial service.

"You kids should consider how lucky you are. Up to now, emigrants to Ganymede have had to spend two years and nine months in space, just to get there. You're making it in two months."

"Couldn't we go faster?" somebody wanted to know.

"We could," he told us. "But we don't need to and it runs up the astrogation and control difficulties. In these new ships the power plant has gotten 'way ahead of the instrumentation. Be patient; your grandchildren will make the trip in a week, blasting at one g all the way. There'll be so many ships they'll have to have traffic cops and maybe we can come close to shipping out as many people as there are extras bom each year.

"Enough about that," he went on. "Who here can tell me what 'E equals M C squared' means?"

I could have answered but I had already spoken up once and it doesn't do to get a reputation for apple polishing. Finally one of the older kids said, "It means that mass can be converted into energy."

"Right!" Mr. Ortega agreed. "The first real demonstration of that was the atom bomb they set off 'way back in 1945 at Alamogordo, New Mexico. That was a special case; they still didn't know how to control it; all they could do was to make one whale of a big bang. Then came the uranium power plants, but that still didn't amount to much because it was a very special case and only a microscopic percentage of the mass was converted into energy. It wasn't until Kilgore's energy transformation equations—don't worry about them; you'll study them when you are older if you are interested—it wasn't until Kilgore showed how it could be done that we had any idea of how to do what Dr. Einstein's energy-mass equation said, clear back in 1905.

"And we still didn't know how to control it. If we were going to turn mass into energy, we needed more mass with which to surround the reaction, a very special sort of mass that would not turn into energy when we didn't want it to and would hold the reaction where we wanted it. Ordinary metal wouldn't do; one might as well use soft butter.

"But the Kilgore equations showed how to do that, too, when they were read correctly. Now has anyone here any notion of how much energy you get when you convert a chunk of mass into raw energy?"

Nobody knew. "It's all in that one equation," he said, "good old Doc Einstein's 'E equals M C squared.' It comes out that one gram of mass gives nine times ten to the twentieth power ergs." He wrote it down for us: 1 gm. = 9 x l0²⁰ ergs.

"Doesn't look like much, does it?" he said. "Now try it this way:" He wrote down

900,000,000,000,000,000,000 ergs.

"Read it off. Nine hundred thousand million billion ergs. It still doesn't mean much, does it? Figures like that are impossible to comprehend. The nuclear physicists keep a barrel of zeroes around handy the way a carpenter does a keg of nails.

"I'll try once more," he went on. "A pound of mass, any old mass, say a pound of feathers, when converted into energy equals fifteen billion horsepower-hours. Does that give anyone a notion of why the Mayflower was assembled out in an orbit and will never ever land anywhere?"

"Too hot," somebody said.

"'Too hot' is an understatement. If the Mayftower had blasted off from Mojave space port the whole Los Angeles Borough of the City of Southern California would have been reduced to a puddle of lava and people would have been killed by radiation and heat from Bay City to Baja California. And that will give you an idea of why the shielding runs right through the ship between here and the power plant, with no way at all to get at the torch."

We had the misfortune to have Noisy Edwards along, simply because he was from the same bunk room. Now he spoke up and said, "Suppose you have to make a repair?"

"There is nothing to go wrong," explained Mr. Ortega. "The power plant has no moving parts of any sort"

Noisy wasn't satisfied. "But suppose something did go wrong, how would you fix it if you can't get at it?"

Noisy has an irritating manner at best; Mr. Ortega sounded a little impatient when he answered. "Believe me, son, even if you could get at it, you wouldn't want to. No indeed!"

"Humph!" said Noisy. "All I've got to say is, if there isn't any way to make a repair when a repair is needed, what's the use in sending engineer officers along?"

You could have heard a pin drop. Mr. Ortega turned red, but all he said was, "Why, to answer foolish questions from youngsters like yourself, I suppose." He turned to the rest of us. "Any more questions?"

Naturally nobody wanted to ask any then. He added, "I think that's enough for one session. School's out."

I told Dad about it later. He looked grim and said, "I'm afraid Chief Engineer Ortega didn't tell you the whole truth."

"Huh?"

"In the first place there is plenty for him to do in taking care of theauxiliary machinery on this side of the shield. But it is possible to get at the torch, if necessary."

"Huh? How?"

"There are certain adjustments which could conceivably have to be made in extreme emergency. In which case it would be Mr. Ortega's proud privilege to climb into a space suit, go outside and back aft, and make them."

"You mean——"

"Imean that the assistant chief engineer would succeed to the position of chief a few minutes later. Chief engineers are very carefully chosen, Bill, and not just for their technical knowledge."

It made me feel chilly inside; I didn't like to think about it.