The Shoulders of Giants

The Shoulders of Giants by Robert J. Sawyer

It seemed like only yesterday when Id died, but, of course, it was almost certainly centuries ago. I wish the computer would just tell me, dammitall, but it was doubtless waiting until its sensors said I was sufficiently stable and alert. The irony was that my pulse was surely racing out of concern, forestalling it speaking to me. If this was an emergency, it should inform me, and if it wasnt, it should let me relax.

Finally, the machine did speak in its crisp, feminine voice. “Hello, Toby. Welcome back to the world of the living.”

“Where—” Id thought Id spoken the word, but no sound had come out. I tried again. “Where are we?”

“Exactly where we should be: decelerating toward Soror.”

I felt myself calming down. “How is Ling?”

“Shes reviving, as well.”

“The others?”

“All forty-eight cryogenics chambers are functioning properly,” said the computer. “Everybody is apparently fine.”

That was good to hear, but it wasnt surprising. We had four extra cryochambers; if one of the occupied ones had failed, Ling and I would have been awoken earlier to transfer the person within it into a spare.

“Whats the date?”

“16 June 3296.”

Id expected an answer like that, but it still took me back a bit. Twelve hundred years had elapsed since the blood had been siphoned out of my body and oxygenated antifreeze had been pumped in to replace it. Wed spent the first of those years accelerating, and presumably the last one decelerating, and the rest—

—the rest was spent coasting at our maximum velocity, 3,000 km/s, one percent of the speed of light.

My father had been from Glasgow; my mother, from Los Angeles. They had both enjoyed the quip that the difference between an American and a European was that to an American, a hundred years was a long time, and to a European, a hundred miles is a big journey.

But both would agree that twelve hundred years and 11.9 light-years were equally staggering values. And now, here we were, decelerating in toward Tau Ceti, the closest sunlike star to Earth that wasnt part of a multiple-star system. Of course, because of that, this star had been frequently examined by Earths Search for Extraterrestrial Intelligence. But nothing had ever been detected; nary a peep.

I was feeling better minute by minute. My own blood, stored in bottles, had been returned to my body and was now coursing through my arteries, my veins, reanimating me.

We were going to make it.

Tau Ceti happened to be oriented with its north pole facing toward Sol; that meant that the technique developed late in the twentieth century to detect planetary systems based on subtle blueshifts and redshifts of a star tugged now closer, now farther away, was useless with it. Any wobble in Tau Cetis movements would be perpendicular, as seen from Earth, producing no Doppler effect. But eventually Earth-orbiting telescopes had been developed that were sensitive enough to detect the wobble visually, and—

It had been front-page news around the world: the first solar system seen by telescopes. Not inferred from stellar wobbles or spectral shifts, but actually seen. At least four planets could be made out orbiting Tau Ceti, and one of them—

There had been formulas for decades, first popularized in the RAND Corporations study Habitable Planets for Man. Every science-fiction writer and astrobiologist worth his or her salt had used them to determine the life zones — the distances from target stars at which planets with Earthlike surface temperatures might exist, a Goldilocks band, neither too hot nor too cold.

And the second of the four planets that could be seen around Tau Ceti was smack-dab in the middle of that stars life zone. The planet was watched carefully for an entire year — one of its years, that is, a period of 193 Earth days. Two wonderful facts became apparent. First, the planets orbit was damn near circular — meaning it would likely have stable temperatures all the time; the gravitational influence of the fourth planet, a Jovian giant orbiting at a distance of half a billion kilometers from Tau Ceti, probably was responsible for that.

And, second, the planet varied in brightness substantially over the course of its twenty-nine-hour-and-seventeen-minute day. The reason was easy to deduce: most of one hemisphere was covered with land, which reflected back little of Tau Cetis yellow light, while the other hemisphere, with a much higher albedo, was likely covered by a vast ocean, no doubt, given the planets fortuitous orbital radius, of liquid water — an extraterrestrial Pacific.