Dry Slot

Time Passages II

Posted by: Bogon, 9. joulukuuta 2010 klo 20:10 (GMT)

The WU Community Blog list reports that my last entry was posted 24 days ago. That's long enough. It's time to cook up something new, even if it's only a quickie.

Time has been much on my mind lately. The solstice approaches; days are short. We're running out of time for Christmas preparations. The end of another year approaches. I'll have to find a new Dilbert calendar for that special spot on my wall.

I have heard it said that our language reflects our thinking. The example I was given to illustrate this point was that Eskimos have a large number (I forget how many. I am not a linguist.) of words for different types of snow. My own ability to distinguish fine gradations of snow-ishness is largely lacking, but I can list a large number of ways that our language juggles the concept of time.

when
then
soon, now, late
sooner or later
before, during, after
anon, moment, already
about time, sometimes, a while back
newfangled, modern, passé
making time, doing time, losing time
time to smell the roses
I was, I am, I will

So what is it, this thing called 'time', that occupies so much of our thinking? That turns out to be a very tough question, one for which I have yet to find a satisfactory response. Physicists often refer to time as the fourth dimension, but that begs more questions than it answers. Mathematical formulae that express physical relationships typically order events along a time axis like frames of a movie on a strip of film. That convention allows physicists to make useful predictions about the nature of the world we inhabit, but it doesn't do much to explain time. Time certainly doesn't behave like any of the three spatial dimensions. You can't travel through time at will. You can only fall headlong into the future.

Einstein's theory of relativity complicates the picture. According to that theory time, space and mass/energy are not mutually independent. They interact. Your perception of events depends, to some extent, on your trajectory through the cosmos. As long as you follow a lazy geodesic path, time will pass in nominal fashion. If you accelerate your clock will slow.

Time has an interesting property of ordering events according to the rules of causality. This is a more complex relation than the spatial property of location, e. g. left or right, near or far etc. You can sort the grains of sand in a hourglass according to their position above the central aperture, yet when the time comes for neighboring grains to pass through, the order will be affected by how they jostle together. Knowing the initial position of each grain is not enough.

Time has a one-way arrow. Once steam has escaped from the tea kettle, you cannot round it up and stuff it back inside. Entropy has increased. There is no turning back the clock.

Whether or not we can supply a precise definition, most of us have an intuitive grasp of time, for we live our lives timewise. You don't even need a clock. You can listen to your heart beat or watch the world spin from day to night to day. A simple pendulum, the stars, the tides, the turning seasons — there are a thousand signs of time's inexorable passage.

We can gauge time very precisely. The quantum clocks at the National Institute of Standards and Technology keep time to an accuracy of better than one second in a billion years. Close enough for government work, eh?

Despite this technical tour de force, most of our experience of time is subjective. If you want time to pass quickly, do something fun. If you want to live forever, get in line at the DMV. If you have all day to amble across the street, the wind will be at your back. But if you're in a hurry, if time is short and your mission urgent, then you can be sure to find only darkness, bad weather and gridlock on the highway. Traffic signals will turn red as you approach. Emergency vehicles and funeral processions will magically appear in your lane. WIDE LOAD banners will obstruct your view. All the laggard drivers in the world will vie for space ahead of you, each trying to outdo the next in demonstrating self-righteous slowness. Meanwhile a hoard of speeding maniacs will materialize on your back bumper honking horns and making threatening gestures in your rear view mirror.

Time is a one-way trip, yet paradoxically it often appears cyclic. The clocks we use to measure time depend on periodic phenomena, whether it be the swing of a pendulum, the oscillation of an electron or the ponderous motion of a planet.

At the intersection of language and subjectivity lies poetry. Here are a few more words about time.

At the still point of the turning world. Neither flesh nor fleshless;
Neither from nor towards; at the still point, there the dance is,
But neither arrest nor movement. And do not call it fixity,
Where past and future are gathered. Neither movement from nor towards,
Neither ascent nor decline. Except for the point, the still point,
There would be no dance, and there is only the dance.
I can only say, there we have been: but I cannot say where.
And I cannot say, how long, for that is to place it in time.

– from Burnt Norton by T. S. Eliot