Robert J. Sawyer is the Hugo, Nebula, Campbell Memorial, Heinlein, Hal Clement, Skylark, Galaxy, and Seiun Award–winning author of twenty-three science-fiction novels, including the trilogy of Hominids, Humans, and Hybrids, which won Canada’s Aurora Award for the Best of the Decade, and the No. 1 Locus bestsellers Calculating God, Triggers, and Quantum Night. Rob holds two honorary doctorates and is a Member of the Order of Canada, the highest civilian honor bestowed by the Canadian government. Find him online at



Mental Time Travel

Science fiction’s grandfather, H.G. Wells, invented many of the field’s subcategories: time travel in The Time Machine, alien invasion (and indeed alien life) in The War of the Worlds, gravity manipulation (including antigravity) in The First Men in the Moon, invisibility in The Invisible Man, and bioengineering in The Island of Dr Moreau. He was so crucial to the development of our genre, we’ve willingly grandfathered all of his big ideas into SF, including time travel—and that is the real grandfather paradox.

In The Time Machine, Wells does a fabulous job of synthesizing everything late Victorian science and philosophy knew about that “recondite matter” (as his narrator calls it) of the nature of time. But in the gap between the publication of Wells’s story and Hugo Gernsback giving our field a name, the two greatest breakthroughs in physics occurred: Albert Einstein’s relativity and the birth of quantum physics. And, yes, relativity provides for a kind of one-way time travel into the future, the dawn of the twentieth century pretty much ruled out any possibility of the sort of time machine Wells—or all of his countless imitators—have written about.

There is a science of time; there’s no science (except of the fringe variety) of physical time travel—and the best evidence that there never will be was the lack of spectators from the future on hand when Neil Armstrong became the first human being ever to set foot upon another world.

But note the adjective I slipped in up above: physical time travel. What about mental time travel—in which consciousness is all that’s displaced?

William Gibson, this year’s SFWA Grand Master, gave us the term cyberspace in his 1984 novel Neuromancer. Although we use that term now as a nerdy synonym for the World Wide Web, Gibson had a very specific definition for it: “A consensual hallucination experienced daily by billions.”

In truth, there is no such cyberspace—no universally agreed upon version of the web. Mine is in English and marred by hateful speech and degrading pornography; another user’s is in Chinese and subject to official censorship. And online we live in tiny pockets of shared interests that are invisible to everyone else.

But there is a consensual illusion: a reality that each of us firmly believes that every other human being—and, indeed, every other living thing on this planet—shares with us: the moment we call now.

As I write this, a command in my word-processing program inserts the current date and time: Wednesday, February 27, 2019, at 8:18:54 p.m. That’s my now. And yet, as you read this, you are accessing my thoughts not as they exist at your now, but at a now that has receded into your past, back when I composed these words.

At least, that’s the way we think time works; that is, that the moment of now, not cyberspace, is our consensual hallucination. Yes, we know the consequences of relativity—including that the faster you travel the slower time passes for you—but that’s an abstraction. I’ve been lucky enough to meet over a dozen astronauts and cosmonauts, but not a one of them is as much as a second out of synch with me due to his or her high-speed space voyaging and, since returning to Earth, we’ve remained in utter lockstep.

But what if not all of us share this consensual illusion? What if this isn’t the year 2019 for everyone? Oh, sure, it is for you, but maybe it isn’t for me. Maybe it’s 2012 for me, and the composing of these words is years in my future. Or maybe it’s 2099, decades from now, and I’m long dead. What makes your psychological construct of now automatically the same as mine? And if we do happen to share that belief about what particular instant is now, could we then by mutual agreement force a different consensual hallucination? If we wanted—to riff on the title of a classic Star Trek time-travel episode—tomorrow to be yesterday, could we—more Trek—make it so?

Of course, now is a special moment; Martin Luther King said it has a “fierce urgency.” A physicist would be less poetic and simply say it is the demarcation between what is fixed and immutable (the past) and that which is undetermined and still changeable (the future). But different human cultures do conceptualize time differently. Most Westerners picture the future as lying ahead of us and the past as behind; we look forward to tomorrow and back on yesterday. But the Aymara of the High Andes do the reverse: only the past, which is fixed, can be viewed, and they visualize it as being in front of them; the future, ever hidden, is an unseeable mystery to the rear.

Audrey Niffenegger’s 2003 debut The Time Traveler’s Wife is a great science-fiction novel about shifting perceptions of when now happens to be. Not only is it extraordinarily well-written and moving, but her story of librarian Henry DeTamble, unstuck in time, popping in and out of the life of artist Clare Abshire, pays rigorous attention to the underlying scientific rationale for his temporal peregrinations and the attendant paradoxes. Kurt Vonnegut, of course, explored a similar notion of asynchronous perceptions of time in his earlier (perhaps!) 1969 novel Slaughterhouse-Five.

The movie Arrival, based on my friend Ted Chiang’s wonderful novella “The Story of Your Life,” also deals with the notion of precognitive time travel: no physical movement in time (and no machine), only an untethering of consciousness from a now advancing inexorably second-by-second in only one direction. And I myself sent human consciousness traveling through time in my 1999 novel FlashForward (and in the 2009 TV series based on it).

Many cognitive anthropologists contend that the ability to foresee possible futures—and, indeed, to plan months, years, or even decades in advance—is the chief distinction between human consciousness and all the other forms of animal awareness that exist, and so is the key to our species’ success. If that’s so, then mental time travel isn’t just a great science-fictional plot device, it’s also why we’re here at all. Current world affairs might suggest that Homo sapiens—“Man of Wisdom”—is a bit too self-congratulatory a name for us, but Homo temporis—“Man of Time”—might indeed be apt, and it’s about time (so to speak) that we recognize that.

Copyright © 2019 by Robert J. Sawyer