The Last Theorem - Arthur Charles Clarke [35]
Vorhulst gave them a few moments to figure it out, but no one did. “It means,” he told them, “that the farther your trip, the faster the speed that you’ll attain. You wouldn’t want to use an electric rocket to go to the moon. Short trip; you don’t really have time to get going very fast. For Mars, though, it’s optimal. And for the outer planets, say Uranus or Neptune, why, that trip doesn’t take much longer than to Mars! And if you’re really going to go a far piece, say to the Oort cloud, you build up so much velocity with all that acceleration that that enormous journey in fact becomes feasible!”
Then he stopped and grinned. “Well,” he said, “I don’t want to oversell you on the electric rocket, because it has one serious fault. That is, we don’t have any.” He overrode the faint groans of disappointment. “Oh, it’s legitimate in principle, all right. But nobody has ever built one because if you have to start your flight from Earth’s surface, they won’t work. They need something to lift them into low earth orbit first, and then they can strut their stuff. Something like an Artsutanov space elevator, and, as you know, we just don’t have one of those around anywhere.”
He gave them a rueful smile. “Oh, one day we will,” he promised. “Then we’ll have electric rockets by the zillion, and I’d be willing to bet that more than one of you will be riding to all sorts of weird and wonderful places. But not yet, because at the present time they don’t exist.”
Which, when you stopped to think about it, was true enough, at least for the little volume of space near Earth, though it wouldn’t be for long.
Actually, somewhat farther away, there were 154 of those electric rockets that were already taking direct aim for Earth, and the individuals aboard them didn’t think they were unusual at all.
These individuals were the One Point Fives, and they (or their ancestors) had been traveling from star to star in spacecraft just like these for many, many generations. Always on much the same errand, too. The fact of the matter was that the One Point Fives had a unique place among the subordinate sapient species of the galaxy.
Basically they were the Grand Galactics’ hit men.
To a casual observer the One Point Fives might not have seemed to be good candidates for that sort of employment. Stripped of their shields and prostheses the average One Point Five wasn’t much bigger than a terrestrial cat. That casual observer would not be likely, however, to see a One Point Five in that stripped-down condition. A One Point Five’s indispensable protective devices massed just about half as much as his body itself (hence the name One Point Five), and every last bit of these devices was vitally necessary. Some of the devices guarded the fragile organic being inside against radiation—from the ionizing spillover from their nuclear power plants or from the residues of their many long-ago nuclear wars. Or even against the lethally high ultraviolet rays that came from their star and were no longer warded off by their planet’s ozone layer because their earlier activities had resulted in their planet’s no longer having one. Some of their chemical processors removed poisons from the air they breathed or the food and water they ingested. Some merely kept them from going insane from the unbearable din that suffused every part of their world (that took blanketing sound absorbers backed up with frequency nullifiers). Other processors toned down the maddening flashes and flares that accompanied their industry.
There were a few isolated spots on their planet where a One Point Five could strip naked and survive. Those places were the breeding rooms and the birthing rooms, as well as a scattering of spots where medical and surgical procedures were performed. There weren’t many of those. Because there