What Time Is It?; Scientific American Time; Special Editions; by The Editors; 1 Page(s)

That simple question is probably asked more often today than ever. In our clock-studded society, the answer is never more than a glance away, and so we can blissfully partition our days into ever smaller increments for ever more tightly scheduled tasks, confident that we will always know it is 7:03 p.m.

Modern scientific revelations about time, however, make the question endlessly frustrating. If we seek a precise knowledge of the time, the elusive infinitesimal of “now” dissolves into a scattering flock of nanoseconds. Bound by the speed of light and the velocity of nerve impulses, our perceptions of the present sketch the world as it was an instant ago—for all that our consciousness pretends otherwise, we can never catch up. Even in principle, perfect synchronicity escapes us. Relativity dictates that, like a strange syrup, time flows slower on moving trains than in the stations and faster in the mountains than in the valleys. The time for our wristwatch is not exactly the same as the time for our head. It is roughly 7:04 p.m.