When I started drafting this review of James Gleick's Time Travel: A History, I had a severe case of writer's block. I stared at my computer, at the keyboard, at the book itself. All in vain. No words came. So I walked away from my computer, hoping that doing something else would help. Suddenly, there was a brilliant flash of light. Shielding my eyes from the blinding beam, I saw a shadow emerge from a portal in front of me. When the portal disappeared, the light went with it, and I could make out the shadow. It was me. "What’s going on?" I asked myself, and... my self.
"I'm you, from the future," my self said.
"Does this mean time travel is real?"
"Yes. And I've come from the future to tell you how you should start your book review."
Now, this probably didn't happen (not in this timeline, anyway), since here, on what I perhaps arrogantly assume is Earth-Prime, we don't have time travel. Thus, Gleick's book is not a how-to manual or a history of actual time travel. It is, instead, a history of the concept. And it is a book whose time has come. For even though time travel has not (yet?) become a reality, the idea has thoroughly suffused our culture. When Gleick asks if the reader, "a citizen of the twenty-first century ... can recall when you first heard of time travel?" Most of us probably can't.
Yet even if we can't recall our first exposure to the idea, we can't avoid it. It's everywhere, "in the pop songs, the TV commercials, the wallpaper," as Gleick puts it. It even briefly became a political issue when Jeb Bush responded to a surge in "Would you kill baby Hitler?" rumination with an enthusiastic "Hell yeah!"
But time travel is more than just a fad, or a fun way to complicate things. If it were only that, its appeal never would have transcended H.G. Wells, its credited literary inventor, or Robert Heinlein, Isaac Asimov, David Gerrold, and other science fiction writers who have explored every conceivable paradox since. Gleick's examination rightly extends the idea of time travel into the related items that explain its transcendence: memory, regret, change, antiquity, posterity, possibility, paradox, free will, fate, determinism, quantum mechanics, the difficulty of defining time itself. In doing so, Gleick consults a host of other figures, both literary—T.S. Eliot, Jorges Luis Borges, Marcel Proust, James Joyce, David Foster Wallace—and scientific—Richard Feynman (the subject of one of Gleick’s previous books), Albert Einstein, Kurt Gödel, Stephen Hawking—all of whom have, in a sense, been time travelers.
Gleick keenly notes the subtleties and contradictions of time travel's effect on our perception of reality and culture. When time travel appears in fiction, our language quickly becomes inadequate: "before and after have to do double duty as prepositions of space as well as time," and, after enough paradoxes, "suddenly, English doesn't have enough pronouns." Though Gleick explores both in detail, he has little patience for time capsules ("a special kind of foolishness") or the "many worlds interpretation" of reality, which posits an infinite number of universes, representing every possible outcome ("a fantastic piece of make-believe championed by some of the smartest physicists of our time").
Gleick has obviously read much of the fictional and scientific literature on time travel, and writes clearly enough not to lose his readers. He breaks down often-confounding concepts, such as the grandfather paradox, so that we can understand them, if not resolve their eternal quandaries. Even so, at times, Gleick's book is so full that one feels as a time traveler might while hurtling uncontrollably along the space-time continuum (though this might have been a function of how quickly I read this engaging work).
If there is one flaw in Time Travel (to say nothing of the flaws in time travel), it is Gleick's treatment of the past. He is right that the "temporal dissonance" of the modern age—the sheer rapidity by which we transport ourselves and information—is related to the emergence and popularity of time travel as an idea, and that time travel is largely "a fantasy of the modern era." But there are exceptions to that latter generalization (some of which he notes). And it seems a bit strong to say that "in bygone times, people had no more than the barest glimmerings of visiting either the future or the past. It seldom occurred to anyone. It wasn't in the repertoire." Historical literature, myth, and religion are full of connections to the past and to one's ancestors, and to the future and to one's posterity. Gleick doesn't need to limit the temporal consciousness of our ancestors to prove time travel's novelty.
These minor defects are forgivable. Gleick has given us an excellent survey of time travel in all of its paradoxical glory. He even suggests why we might need the idea. "For mystery. For nostalgia. For hope. To examine our potential and explore our memories. To counter regret for the life we lived, the only life, one dimension, beginning to end." Perhaps. But until someone invents a time machine and figures this all out for real, Gleick's book will be worth a read—in all possible worlds.
Now if you'll excuse me, since I'm done writing my book review, I need to travel back in time to tell my past self how to start it. How did it go again? Oh, that's right: When I started drafting this review of James Gleick's Time Travel: A History, I had a severe case of writer's block...