"I think so. I can't really be sure."
They paused on the low ledge where he had stood earlier and watched the girls gather their data for the reports. At their feet the waves washed up to the edges of the tide pools, eddying into and out of them softly. The water looked dark and cold, but they knew that it too was warm.
"There've been lots of changes, and they all fit a pattern," he said. "The temperature. The difference in salt content in the water. The higher tides. Those things could happen for several reasons. But there's only one explanation for the other changes, the ones I found on the star charts."
She waited. The water lapped in and out, reaching almost to where they stood.
"The Earth rotates faster now," he said. "And the stars are nearer. Much nearer than they were."
"Isn't that impossible?"
"How do we know? We exceeded the speed of light. Who could say what continuum that might have put us in? I remember an analogy I read once, in a layman's book on different theories of space-time. '—The future and the past, two branches of a hyperbola, each with the speed of light as its limit—'"
"You mean," she whispered, "that we're not in the future at all? We're in the past—the far past—before there was any life on Earth?"
