Set Your Clocks for the Twilight of the Big Bang

This Sunday marks the yearly orgy of clock-adjusting known as daylight saving time. As an astrophysicist concerned with cosmology and the origins of the universe, this is the best day of the year to remind everyone that time, as we know it, doesn't exist.

For generations, we have been taught to think of time as something absolute, dictated to us by God or the laws of nature or the Big Bang. Yet on Sunday, 300 million Americans will wake up to a 7 a.m. that did not exist as 7 a.m. the day before.

Where did the hour go? And what does it mean to live in a world where time can get shuffled around like books on a shelf? It means the time we live with is, essentially a cultural idea and not a cosmic construction.

Let's think about what time was like 5,000 years ago. Back then, humans had no concept of hours and minutes. Folks floated on a flexible time determined by nature: the sun, the moon and the seasons. Even during the Greek and Roman Empires, time was elastic. Sundials counted 12 hours of daylight -- no night hours -- and the length of these daylight hours changed with the seasons. An hour in the summertime could be as long as 75 minutes and an hour in the winter as short as 45.

By the 1700s, as clocks became portable and showed the minutes of each hour, we began standardizing time. It's no coincidence that these more accurate portable timepieces eventually helped usher in the Industrial Revolution and with it all the trappings -- and traps -- of modern life. The transportation, communication and manufacturing industries grew because everyone could be "on the same clock." Indeed, it was during the 18th century that Ben Franklin first proposed the idea for daylight saving as a way to improve worker productivity, an idea that finally became enacted by the federal government in 1966.

Greeks and Romans lived in a world bound by natural time; today we live in a world bound by gadgets and technology and laws that regulate when we have to turn our clocks back. We live in a forced time.

Why are we holding onto this old way of timekeeping?

Many physicists, myself included, will tell you not to. Cosmologists are now second-guessing the 60-year-old theory of the Big Bang and working on new ideas about the universe that will radically alter our understanding of time. Some of these theories sound a lot like science fiction involving parallel universes and hidden dimensions. Others go so far as to tell us that time is an illusion -- that each moment of our lives exists separately and forever.

We do not know which of these theories is correct. But we know that in 25 to 50 years our understanding of the universe -- and time -- will be very different from the one we live by today. Until then, we should all take a deep breath and relax, knowing that the tick-tock of our harried lives is not dictated by any natural force in the universe. It's all... well, made up. Since we were the ones who figured out how to measure time; our task now is to invent a better way to live with it.