PHYSICS, BIOLOGY, AND TIME
Time waits for no man, the old saying goes, and one might add that no man has much of an idea what would wait for him if time did do so. Our words before and after, yesterday and tomorrow and a host of others refer to an aspect of human experience so universal and ordinary that we scarcely give it a second thought. Yet we take for granted a something to which we give the name time. Everybody knows what it is--but actually when you look at it closely, this major mystery of the. physical universe is a complete enigma.
To be sure, we do many things with time--besides spending, wasting, and conserving it. We build a mechanical device called a clock, chop time into pieces called hours, and thereby schedule the lives of millions of people. What is it we chop with the clock? What is this fundamental universal Time that seems to flow, steadily, relentlessly, and forever, from past to present and into future throughout the universe we know?
Philosophers try to answer this question, but the philosophers do not all agree. Most experimental scientists, by contrast, don't try, for to them questions about time