The future might already be written. Cheer, shudder, or eye-roll in disgust, but history shows that what awaits us is often spelled out in the pages of science fiction. The genre's predictive track record stretches millennia: Authors mused about the lunar landing as far back as 175 A.D., when Syrian satirist Lucian of Samosata imagined flying ships to the moon, a tale that tapped the seafaring culture's desire to ascend to the heavens. Fiction isn't always pure fantasy. "Some of our greatest authors are not making up stuff whole cloth, but sampling from the zeitgeist—scientific or otherwise," says Dan Rockmore, director of Dartmouth College's Neukom Institute for Computational Science, which hands out annual prizes for visionary speculative writing. Of course, scribes do have blind spots. They never quite nailed the smartphone (easy, Trekkies—those communicators are more like fancy pagers). Here's a glimpse of what sci-fi writers of yore got right.