Time Travel: A Writer's Guide to the Real Science of Plausible Time Travel

Preface

P R E F A C E It is so very sad to see some valuable minds writing such a pile of unmitigated bullshit. one physicist's unhappy reaction to the proposal of two other physicists that the Higgs boson could ripple backward through time and stop the Large Hadron Collider before it could make the particle in the first place (quoted from Physics World, December 2009). Clearly not all physicists have accepted the possibility of traveling through time into the past. Other highly respected physicists do take the idea of backward time travel quite seriously. Richard Gott at Princeton, Frank Tipler at Tulane, and Kip Thorne at Caltech are perhaps the three best-known examples, with each having"invented" (on paper, not in their basements!) time machines that are discussed in this book: Gott's cosmic strings, Tipler's rotating cylinder, and Thome's wormhole. Even Stephen Hawking, who has not been shy about expressing his belief that time travel is nonsense, admits that his objections are of a "gut-feel" nature, and that there is nothing in knownphysics that actuallyforbids time travel into the past. The unavoidable violation of the conservation of energy is the fatal flaw in the construction of a perpetual motion machine, for example, but there are no known conservation laws that a time machine would necessarily violate. A story that uses time travel as part of its plot is, therefore, not to be automatically rejected as being simply an adult fantasy just because it includes time travel. Time travel has longbeen a central concept in science fiction, but, in the past twenty years, it has also become a hot topic in physics. Serious scientists, on both sides of the issue, have been engaged in highly analytical discussions about time travel. It is ironic, then, that Preface ix the very first truly "modern" time travel story—that is, a story based on "plausible" science—was written more than 115years ago, a full decade before Albert Einstein published the special theory of relativity (with its four dimensional space-time that theoretically allows, without controversy, travel into the arbitrarily far future) and two decades before Einstein's general theory and its warped space-time, the scientific basis for gravity (and for time travel into the past). I am, of course, referring to H.G. Wells (1866-1946), who was just twentyeight when The Time Machine appeared (in serial form, starting January 1895) in the New Review. Wells's great contribution with The Time Machine was to make the science part of "science fiction" important . For Wells, the scientific basis for time travel wasn't the yetto -be-discovered warped Einsteinian space-time but instead a much less sophisticated view of the fourth dimension. Other writers contemporary with Wells wrote of time travel, too, but their works were based on such nonscientific literary devices as sleeping into the future as in Grant Allen's British Barbarians (published the same year as The Time Machine), or traveling into the past via a knock on the head from a crowbar as in Mark Twain's A Connecticut Yankee in King Arthur's Court (1889), or by some other equally curious mechanism. Wells, in contrast, used a purposefully designed machine for travel along the time (not a spatial) dimension. There is a problem with Wells's time machine (a difficulty discussed in this book), but it's a subtle one. And so, astonishingly, Wells would not have to read this book, even though he was at a distinct disadvantage by writing years before Einstein, because with that single exception he still got everything else right from a modern scientific point of view! Or, at least, he didn't get anything wrong. That's why I want to talk, here, just a bit more about the remarkable genius of Herbert George Wells than I did in the original edition of this book. The idea of time as the fourth dimension entered the popular mind in 1895 with the publication of the first of Wells's "scientific romances " (his term; the modern term of science fiction was still decades in the future). Wells's The Time Machine has never been out of print and is now recognized as one of the modern classics of the English x Preface language. It has been translated into virtually every other languageon the planet, as well, and it catapulted its author into an overnightliterary sensation...