That is also the best possible time for a rocketship between Kong and L-City. In practice a jumpbug rocket will usually take about half an hour-depends on how high its trajectory is.
But surely a half hour is short enough. Why tunnel under maria and mountains when a rocket can do the job?
A rocket is the most lavishly expensive transportation ever invented. In a typical rocketship mission half the effort is spent fighting gravity to go up and the other half is spent fighting gravity in letting down-as crashing is considered an unsatisfactory end to a mission. The giant catapults on Luna, on Terra, on Mars, and in space are giant statements against the wastefulness of rocket engines.
Contrariwise, the ballistic subway is the most economical transportation ever devised: No mass is burned up or thrown away and the energy used in speeding up is given back at the other end in slowing down.
No magic is involved. An electric catapult is a motor generator. Never mind that it doesn't look like one. In its acceleration phase it is a motor; electric power is converted into kinetic energy. In its decelerating phase it is a generator; the kinetic energy extracted from the capsule is pulled out as electric power and stored in a Shipstone. Then the same energy is taken from the Shipstone to hurt the capsule back to Kong.
A Free Lunch!
Not quite. There are hysteresis losses and other inefficiencies. Entropy always increases; the second law of thermodynamics can't be snubbed. What it most resembles is regenerative braking. There was a time, years ago, when surface cars were slowed and stopped by friction, rudely applied. Then a bright lad realized that a turning wheel could be stopped by treating it as a generator and making it pay for the privilege of being stopped-the angular momentum could be extracted and stored in a "storage battery" (an early predecessor of Shipstones).
The capsule from Kong does much the same; in cutting magnetic lines of force at the L-City end it generates a tremendous electromotive force, which stops the capsule and changes its kinetic energy into electrical energy, which is then stored.
But the passenger need know nothing of this. He simply lounges in his "hammock" rack for the gentlest ride possible.
We had just spent most of three days in rolling seven hundred kilometers. Now we traveled fifteen hundred kilometers in eighteen minutes.
We had to shoulder our way out of the capsule and into the tube station because there were Shriners impatiently awaiting the opportunity to board for Kong. I heard one say that "they" (that anonymous "they" who are to blame for everything)- "they ought to put on more cars." A Loonie tried to explain to him the impossibility involved in his demand-just one tube, able to handle only one capsule, which could be at this end or at the far end or in free flight in between. But never two capsules in the tube-impossible, suicidal.
His explanation met with blank disbelief. The visitor seemed to have trouble, too, in grasping the idea that the ballistic tube was privately owned and totally unregulated... a matter that came up when the Loonie finally said, "You want another tube, go ahead! Build it! You are free to do so; nobody is stopping you. If that doesn't satisfy you, go back to Liverpool!"
Unkind of him. Earthworms can't help being earthworms. Every year some of them die through inability to comprehend that Luna is not like Liverpool, or Denver, or Buenos Aires.
We passed through the lock separating the pressure owned by Artemis Transit Company from the municipal pressure. In the tunnel just beyond the lock was a sign: GET YOUR AIR CHITS HERE. Seated under it at a table was a man twice as handicapped as I was; his legs ended at his knees. This did not seem to slow him down; he sold magazines and candy as well as air, advertised both sightseeing and guide service, and displayed the ubiquitous sign: TRACK ODDS.
Most people breezed back and forth past him without stopping. Bill had started to do so, when I checked him. "Wups! Wait, Bill."
"Senator, I've got to get some water onto this tree."
"Wait just the same. And stop calling me 'Senator.' Call me 'Doctor' instead. Dr. Richard Ames."
"Huh?"
"Never mind; just do it. Right now, we've got to bay sax. Didn't you buy air at Kong?"
Bill had not. He had entered the city pressure helping with Auntie and no one had asked him to pay.
"Well, you should have paid. Did you notice that Gretchen paid for all of us at Lucky Dragon? She did. And now we'll pay here, but I'll arrange for longer than overnight. Wait here."
I stepped up to the table. "Hi there. You're selling air?"
The air vendor glanced up from working a double-crostic, looked me over. "No charge to you. You paid for air when you bought your ticket."
"Not quite," I said. "I'm a Loonie, cobber, returning home. With a wife and one dependent. So I need air for three."
"A nice try. But no prize. Look, a citizen's chit won't get you citizens' prices-they'll still look at you and charge you tourist prices. If you want to extend your visa, you can. At city hall. And they'll collect air fee to cover your extended visa. Now forget it, before I decide to cheat you."
"Choom, you're hard to please." I dug out my passport- glanced at it to make sure it was my "Richard Ames" passport- and handed it to him. "I've been away several years. If that makes me look like a groundhog to you, that's regrettable. But please note where I was born."
He looked it over, handed it back. "Okay, Loonie, you had me fooled. Three of you, eh? For how long?"
"My plans aren't firm. What's the shortest period for the permanent-resident scale?"
"One quarter. Oh, another five percent off if you buy five years at a time... but with today's prime rate at seven point one, it's a sucker bet."
I paid for three adults for ninety days and asked what he knew about housing. "Having been away so long I not only don't have cubic, I don't know the market-and I don't relish dossing in Bottom Alley tonight."
"You'd wake up with your shoes gone, your throat cut, and rats walking over your face. Mmm, a tough question, cobber. You see the funny red hats. Biggest convention L-City has ever had; between it and Independence Day the town is booked solid. But, if you're not too fussy-"
"We're not."
"You'll be able to get something better after the weekend, but in the meantime there is an old place in level six, the Raffles, across from-"
"I know where it is. I'll try there."
"Better call them first and tell them I sent you. I'm Rabbi Ezra ben David. Reminds me. 'Ames, Richard.' Are you the Richard Ames who's wanted for murder?"
"My word!"
"Surprise you? Too true, cobber. I've got a copy of the notice here someplace." He shuffled through magazines and penciled notes and chess problems. "Here it is. You're wanted in Golden Rule habitat-seems you chilled some VIP. So they say."
"Interesting. Is there a tab out on me here?"
"In Luna? I don't think so. Why would there be? Still the same old standoff; no diplomatic relations with Golden Rule until they qualify under the Oslo Convention. Which they cannot without a basic bill of rights. Which is not bloody likely."
"I suppose so."
"Still... if you need lawyer help, come see me; I do that, too. Catch me here any day after noon, or leave your name at Seymour's Kosher Fish Emporium across from Carnegie Library. Seymour's my son."
"Thanks, I'll remember. By the way, who is it I'm supposed to have killed?"
"Don't you know?"
"Since I didn't kill anybody how could I know?"
"There are logical lacunae in that which I will not examine. It is set forth here that your victim hight Enrico Schultz. Does that name trigger your memory?"
"'Enrico Schultz.' I don't think I've ever heard that name. A stranger to me. Most murder victims are killed by close friends or relatives-not by strangers. And, in this case, not by me."