Thursday, 12 May 2016
Does time have a future? Yes, but how much of a future depends on what the
ultimate fate of the cosmos turns out to be.
Iaac Newton had a peculiar notion of time. He saw it as a sort of cosmic grandfather
clock, one that hovered over the rest of nature in blithe autonomy. And he believed
that time advanced at a smooth and constant rate from past to future. “Absolute, true,
mathematical time, of itself, and from its own nature, flows equably without relation to
mathematical time, of itself, and from its own nature, flows equably without relation to
anything external,” Newton declared at the beginning of his Principia. To those caught
up in the temporal flux of daily life, this seems like arrant nonsense. Time does not strike
us as transcendent and mathematical; rather, it is something intimate and subjective.
Nor does it proceed at a stately and unvarying pace. We know that time has different
tempos. In the run-up to New Year’s Eve, for instance, time positively flies. Then, in
January and February, it slows to a miserable crawl. Moreover, time moves faster for
some of us than for others. Old people are being rushed forward into the future at a
cruelly rapid clip. When you’re an adult, as Fran Lebowitz once observed, Christmas
seems to come every five minutes. For little children, however, time goes quite slowly.
Owing to the endless novelty of a child’s experience, a single summer can stretch out
into an eternity.
One way researchers have tried to measure the subjective flow of time is by asking people
of different ages to estimate when a certain amount of time has gone by. People in their
early twenties tend to be quite accurate in judging when three minutes had elapsed,
typically being off by no more than three seconds. Those in their sixties, by contrast,
overshot the mark by forty seconds; in other words, what was actually three minutes
and forty seconds seemed like only three minutes to them. Seniors are internally slow
tickers, so for them actual clocks seem to tick too fast. This can have its advantages:
at a John Cage concert, it is the old people who are relieved that the composition 4'33"
is over so soon.
