"I talked about rotating an electron last time because I wanted you to get ready for some other rotating phenomena —not just in space, but in space-time.
"I have here in my hand a bust of Abraham Lincoln. Look it over. It has three spatial dimensions—top/bottom, left/ right and back/front. Since I am now holding it what we call 'upright,' I share those dimensions and directions with it. My 'up' is the same as Honest Abe's 'up.'
"Now let's rotate it ninety degrees—standing old Abe on his right ear, as you see. I have rotated it on its back/front axis, and now the bust is lying on its right side. The direction I would call 'up' is now 'left' to Abe. Contrariwise, what is 'up' to Abe Lincoln is now what I would call 'right.' But that doesn't cause any real confusion. The only people who are confused would be outside observers. Both Abe and I see clearly that up, right, back, front and so on remain in the same direction as ever—relative to our own individual selves.
"All that is such simple stuff that you don't even need to think about it ... in three-dimensional space.
"But we're thinking now about space-time, and space-time has four dimensions. The other dimension is past/future; it is the dimension of time.
"So, while in 3-D space we had a choice of three axes to twist the sucker around on, now in 4-D space-ftwf we have a choice of four.
"When we rotated Abe's bust in 3-D, his left/right became our up/down. But what if his left/right now becomes our past/ftiture? Nothing's going to look different to Abe. He still sees left and right as left and right.
"But how does he look now to us?
"I'm going to leave you with that question for a while. We won't come back to it for a while, but when we do I'm going to relate it to the proposition we call 'CPT invariance.'"
And the aiodoi sang:
"What is so is so.
"What is right is right.
"That is the real and the only invariance."
10
What Sue-ling Quong felt was excitement, what Sork Quintero felt was savage joy at the prospect of attaining his life's ambitions, but what Sork's twin brother Kiri Quintero mostly felt was relief.
Kiri's relief was not complete. It was tainted by the passions he could still feel floating around the control room, even though the main disputants had finally agreed—if not on any long-range covenant, at least to stop their bickering for a while. It had been hot and heavy for a while there. Kiri himself had found his peaceful calm fraying, and even Moon Bunderan's Taur had been restive, tossing the great horned head and lowing from time to time in unhappy protest as the fight went on.
Now there was a break. Kiri looked up as Sue-ling and Moon came in, with Krakc's half-human crew. "Over here," he called to Sue-ling. "We're going to go into wave-drive—and we're all going to get our first lesson in space piloting!" He nodded toward Francis Krake, who raised his head from one of the control banks long enough to glower up at them.
Sue-ling looked around uncertainly. "What's been going on here?" she asked.
Kiri slipped a reassuring arm around her, enjoying the warm, solid feel of her body. "Oh," he said, aware of his brother's eyes on them but not looking toward him, "those three have been going around and around for the last half hour." He jerked a thumb toward the two Turtles, standing immobile as granite, flanking Krake at the control board. "I guess the Turtles won," he added, lowering his voice, "because Krake finally threw up his hands and said he'd take off. But they didn't really agree on anything, I'd say. I think that's what he's so ticked about."
"May I?" Daisy Fay said politely, and Kiri moved out of the way to permit her to slip her ungainly metal body into the space where the board operator's seat should have been. "Thanks," said Daisy Fay, turning one eyestalk toward him. "Did anybody tell you what we do here?"
Kiri shook his head. "They were all too busy fighting," he said.
Daisy Fay chuckled. "I think we're going to see a lot of that. Anyway, this position is only the state-of-the-ship board. It doesn't actually fly the Hind. All you do here is watch out for signal lights. If any of them turn red, then there's trouble." The pretty face on the plastron grinned up at him. "But none of them ever have," she added.
"I didn't know the Turtles used red for a warning color," Sue-ling put in.
"Far as I know, they don't. This is our control room. They designed it to our specifications and put it into the shielded section when they leased the ship to Francis." One eyestalk twisted around to look at Francis Krake. "Captain?" she called. "Are we ready for wave-drive insertion?"
Krake didn't look up. "Board green," he called, his eyes fixed on the controls.
"Green," Daisy Fay repeated. Her fingers danced over the board for a moment, and Kiri Quintero felt a sudden lurch as the mass-thrusters gave The Golden Hind a gentle nudge. "Correcting orientation," Daisy Fay called. In an undertone she explained to Kiri, behind her, "We want to be pointed in the right direction."
"Locked on course," Krake called from the other board.
Daisy Fay's tentacles moved rapidly across the board. "Stand by for wave-drive," she said, her eyestalks glancing up to look at the screens. Kiri could not help following her glance. It was a startling spectacle. Earth appeared behind the orbit station, no more than a thin blue crescent. The Sun rolled into visibility, but diminished by the screens to no more than a tarnished copper coin.
"Wave-drive on," cried Francis Krake.
And the bottom dropped out of Kiri Quintero's stomach, and he felt himself falling.
In Kiri's dream he was being held tenderly by a woman who was not Sue-ling Quong. She was not really a woman at all. She was a red-shelled monstrosity that had seized him with blood-colored tentacles; and when he opened his eyes the dream was no dream at all.
"It's all right, Kiri," said Daisy Fay McQueen's reassuring voice. "I know it felt pretty strange, but it was only the shift to wave-drive. It must've hit you hard."
Kiri pushed himself free of her embrace, surprised again to feel himself of a normal weight. "It did," he said dizzily, staring around. He wasn't in the control room any more but in a tiny compartment with a bunk in it. "I—I thought I was falling—" He found himself covered in sweat, and let the woman in the hideous machine help him to lie down on the bunk. "Why are we in gravity again?" he asked plaintively, looking up at her.
"We're not, really. The sensation is just an artifact of the wave-drive." Daisy Fay touched a control, and screens like the ones in the control chamber appeared around the room. "We're picking up speed now," she told him. "There's Earth, and over there—" (Kiri blinked at an impossibly crimson disk, shrinking from sight.) "—that's Mars. The colors are the way they are because they've red-shifted because of our velocity. Of course," she went on, lecturing as to a child, "we don't really see them. We don't have anything material to see with any more. Our own wave train is transparent; radiation passes right through us. But instruments can still pick up interference effects, and that's what we show on the screen."
"We'regoingV He pushed himself erect.
"That's right, Kiri," the metal-woman said, waving her tentacles affirmatively. "Now you'd better get some sleep. I'm on shift in four hours, and you're supposed to come with me to learn how to pilot a waveship."
He gazed up at her uncertainly. "All right," he said, and started to turn away. Then he stopped himself, out of the habit of a lifetime. "Where's Sork?" he asked.