Tor, 1998, 383 pp., $25.95
Some Poul Anderson’s recent books have tended to be preachy; happily, Starfarers isn’t.
Anderson imagines the ultimate STL drive: It’s little short of magical, but this isn’t an engineering text. With the drive an average velocity of 99.99% of c can be obtained, so time dilation makes trips to the nearby stars quite practical. A trip to a star forty light years off takes eight weeks ship time but forty years back on earth. The travelers arrive back on Earth eighty years after they departed; their contemporaries are dead and gone and society has changed significantly.
Anderson has the crews of the interstellar ships band together for their own sanity, effectively forming a new, small, nation which is centered on Earth, but which is evolving 20 or 30 times slower than Earth-bound nations. Naturally, only a tiny fraction of the starfarers are on Earth at any time, and few stay for long.
Ships propelled by the drive can be detected at great distances. Astronomers discover a cluster of spaceship tracks at about 5000 light years off — spacefaring aliens! An expedition is readied and the bulk of the story tells of that expedition. Though the story of the expedition was well done, I found the sense of what was happening on Earth during the ten thousand years they were gone to be even more interesting.
Nearly alone among SF authors, Poul Anderson has a gut-level sense of what time can do. He shows Western civilization evolving into alien ways and eventually disappearing; new peoples conquering and settling North America; new religions replacing old and new languages evolving. By the time the expedition returns, Earth has become completely alien.
There’s a fairly happy ending — the returning expedition brings back enough new technology to revitalize interstellar travel and founds a new society based on one of Earth’s abandoned colony worlds which is much like 20th century Earth.