As I write, it is a cool, overcast late-March afternoon in Toronto. Through my study window, the sky is a featureless pewter grey and the leafless trees look like dark coral. What shadows there are appear more like faint stains than black silhouettes. A week ago today was the first official day of spring, and yesterday I saw a couple of robins stalking my slowly greening lawn. But today looks decidedly unspringlike.
Around noon some snow fell, a deluge of large flakes that settled so slowly it seemed as if the air had thickened into a fluid — as if my house were on the floor of some great ocean. The thumbnail-sized crystals filled the sky in a slow-motion cataclysm for a few minutes and then stopped as if they had been a hallucination, leaving only damp spots on the bricks of the pathway that winds through the yard to my garage. Now even those spots have evaporated.
In an hour, I’ll have to dress and leave for a wedding. The bride is an old friend of mine and it is her second marriage. I wonder what she is thinking right now? As I imagine this, she seems to step into my vision of “now.” But “now” is even bigger than that. It includes the whole Earth. Half a world away, in the African bush where it is already night, the Serengeti jackals are on the prowl, keeping a wary eye out for nocturnal lions. In the Antarctic, on the other side of the planet, it is late fall and the sun has stopped rising above the horizon. Knowing how frequently the moon is pelted by small meteorites, I can guess that, at this instant in time, a small meteorite the size of a pea is soundlessly striking the surface of Mare Imbrium at 145,000 kilometres per hour. The heat of the impact melts some of the lunar soil into a dark, glassy pit. All this happens...in the immensity of now.
But it is also true to say we know that the present moment is very brief, so brief that it may be one-dimensional, perhaps even less than flat. Saint Augustine certainly thought so at the end of the fourth century. He likened the present to a knife-edge that separates the past and the future. He said it could not be divided into smaller parts, that it had no extension in time, that “now” was non-dimensional.
But “now” is also cultural. The pulse of fashion that constantly reinvents and transforms our world is a kind of attenuated “now” that lasts a season or longer. Even entire eras are another kind of “now,” though ones with many subdivisions. Of all times, perhaps our own is the most complex. We live our lives in a layered media nest of competing times, wrapped in the past, present, and future. Television, movies, and music continually resurrect history and even prehistory until it seems as if all of time is available to us. My generation, the boomers, has been the narcissistic focus of this voracious nostalgia. We have lived in a charmed “now” all our lives — our tastes and predilections have driven the Western economy. But now our youth and dominance are ebbing. We are rationalizing cosmetic surgery and advocating life-extension therapies with a passion we once directed toward social change.
Our time-obsessed generation, with its day planners and lockstep schedules, is now challenging biology with our sense of entitlement and hubris. Rumour has it that Bill Clinton, a vanguard boomer, once said, “We’ll live to 120.” May our now never set. Already the retirement ads on television are portraying younger, more vital seniors who are merely changing careers, not sailing into the sunset. We are pushing “now” into the future as far as we can. But we can’t yet move it through space — where time still does exactly as it wishes.
the speed of now
It would seem logical to think that you could extend the present instant to include the moon and, generally speaking, you can. But when things get farther away, say, the 150-million-kilometre distance to the sun, that simultaneous instant ends. How is that possible? We know that light coming from the sun takes eight minutes to get here, so common sense would tell us that we can easily account for that difference in time, that delay, simply by compensating for it. We can imagine, for example, that the sun could be erupting with a huge solar flare at this very moment, and although it would take eight minutes for us to see that flare, we intuitively think that there is a sort of God’s-eye view of simultaneity. We know the flare is happening “now” — it’s just that we won’t see it right away.
In a slightly more elaborate fantasy, we might imagine that an astronaut travelling close to the sun has a clock on board his spaceship set to “Earth time.” But time is not so portable. Although we have an intuitive idea that there is a single present that encompasses the entire universe, physicists and scientists since Einstein have argued that time is “local.” They believe that time flows at different rates in different parts of the cosmos. If our astronaut set his clock on Earth time, and then sped off at high velocity to the sun, his clock would read a slightly different time than our earthbound watches when he got there.
But why does distance affect time like this? What could change the tempo of time itself?
