Donald Moffitt - Genesis 01

for accelerating fuel. The ramjet idea ought to work fine within a galaxy, of course. There’s plenty of ionized hydrogen around. And the H-II regions get thicker and thicker as you steer for the heart of the galaxy, where the stars are packed closer together. Traveling between galaxies is a different story. Hydrogen pickings would be slim. No matter how much of a gamma factor you managed to pick up in your home galaxy, you’d still have to spend hundreds of years coasting. And how are you going to stop when you get there? You’ve still got to shed all that energy you’ve picked up! Besides, didn’t you hear what Jao said? The ramjet probe’s designed for electronics, not living things. You’d fry long before you got up even to gamma five.”
    “Oh, you’re just trying to be difficult,” Mim said.
    “I rest my case,” Smeth said. “Right, fellows?”
    Trist said thoughtfully, “What you really want to do, Bram, is travel faster than light.”
    “Hey, how about that?” Jao said with a wide grin. “Forget about imaginary photons and all that stuff. Give yourself an imaginary proper mass instead. Still better, forget about relativity altogether. What do you say, Smeth?”
    Smeth started to sputter. “Stop talking nonsense!”
    “Let’s not dismiss it out of hand,” Trist said soberly. “We may be on to something.”
    “Right,” Jao said. “Tachyons. In fact, wasn’t that a pet idea of Smeth’s a while back? They don’t even violate the equations. At zero energy they have infinite speed.”
    “Don’t you ever get tired of playing the buffoons?” Smeth said.
    Jao smiled hugely at Bram and Mim. “All we have to do is break through the skin of the universe. On the other side, we have the tachyon universe, where everything travels faster than light.”
    “Wait a minute,” Trist said. “You can’t break through the skin. All you can do is form a diverticulum. But the surface of the diverticulum is still in space-time.”
    “Oh, yah, I forgot. It’s just warped—like your sense of humor. How about this, then? You send a probe ahead of your ship, like a sacrificial pawn. It accelerates until its relativistic mass is enormous. It warps the geometry of space and sinks into a pit, like a neutron star, only more so. The process continues until it’s sunk so deep— all the way to the center of the plenum—that the pit closes over it. Pinches off, so to speak. And your ship, following close behind, simply skates over the surface of the dimple, thereby skipping a big chunk of its journey. All without leaving normal space-time. Hey, you could even maneuver in space without building up new vectors—just tilt space in the direction you want to go. You could even reverse direction in two or three maneuvers without having to go to the inconvenience of decelerating and building up near-light velocity all over again!”
    “You’ve overlooked something.”
    “Yah, what’s that?”
    “You’re only skipping the part of space that the diverticulum took down to the center of the plenum with it. It may be stretched out to half the diameter of the universe, but you’ve only saved a few light-hours of travel.”
    Jao looked crestfallen. “How about this, then? The universe has a fancy geometry, see? It’s a Klein universe or a Mobius universe. Inside and outside are the same. Or there’s no skin you have to break through to get to your tachyon universe. It’s all the same eleven-dimensional space-time, with a twist. You make your double circuit, and everything comes out backward, like a left-hand glove coming out a right-hand glove. Only we don’t call it antimatter, the way small minds like Smeth do. We don’t turn electrons into positrons, or neutrinos into anti-neutrinos, or anything like that. Shut up a minute, Smeth. No, we do a much cleverer flip-flop. We turn tardyons into tachyons. And vice versa. And there’s no transition point at which the inversion takes place—it’s one continuous circuit. Because tachyons and tardyons are the same thing. It all depends on your point of view. Like a sort of superrelativity. No, let me finish! In other words, tachyons and tardyons must coexist everywhere and are merely different expressions of identical phenomena.” He paused to gloat. “Thus, one may simultaneously travel more slowly than light and faster than light, depending on the position of the observer.”
    “And where does that leave faster-than-light travel, you idiot?” Smeth