It's About Time: What You Don't Know But Should
Humans invented the concept of time. It didn't exist, in the way we know time, before we came along. No other creatures on the planet have the same concept of time as we do. Or, if it did exist, who would know?
Is time real or imaginary? Einstein considered it real, counted it as a component of what he called the fourth dimension, space-time. Space-time figured prominently in projections based on his theory of relativity.
But so did gravity and some physicists (albeit far from a majority) wonder now if gravity is everything Einstein says it is. For example, where is all that Dark Matter that supposedly comprises far more of the universe than the matter we can detect? For that matter (excuse the pun, I couldn't resist), where is all the "real" matter that should exist but we're having difficulty finding since we became aware of the Big Bang and developed big telescopes? University of Maryland astronomer Stacy McGaugh's study shows that many galaxies have much less matter than should be there to account for their gravitational pull.
If gravity is not what Einstein said it is, then that messes up our concept of time. So does the average U.S. city commuter really lose 38 hours a year to traffic delays or is that just imagined? The answer (you're not going to like this, I didn't) is that most of what we believe about our lives is based on how we perceive it (what we imagine it to be) more than on reality. (Okay, I wouldn't have time to explain that even if I could.)
After nearly a century of using Daylight Saving Time (DST), we still aren't sure why we use it. Benjamin Franklin introduced it as a joke. He said that if we got up an hour earlier each morning we could get an hour's more work done in daylight and save candles in the evening. The U.K. adopted DST in 1917, most of the rest of the world followed. (Personally, I can't see sleeping through daylight in the early morning hours in summer when that's often the best time to work outside. The mosquitoes in our area agree.)
Daylight Saving Time accounts for a drop in electricity use. The U.S. Department of Energy claims power demand drops by 0.5 percent during DST, saving three million barrels of oil in the U.S. alone.
By the way, it's not Daylight Savings Time. It's Saving. Savings is an account you have at the bank. That is, you would if you had any money to keep in it.
One study watched how quickly bank tellers made change, pedestrians walked and mail clerks spoke and concluded that the fastest paced U.S. cities are Boston, Buffalo and New York. (As an aside, I have often wondered if rats are insulted when we refer to the fast paced life of humans in cities as the Rat Race. If so, they had better get over it because half the population of the world lives in cities today, most in big cities.)
The psychologist who did that study found the slowest paced cities were Shreveport, Sacramento and Los Angeles. (Nothing in the report about the pace of life of rats in those cities.)
Back in the old days one second used to be defined as 1/86,400 the length of a day. (We'll pause here while you fetch your calculator if you like.) A second can still be defined that way, but it will be a longer second. The friction of tides as a result of gravity by the sun and moon slow earth's travel, lengthening our day by three milliseconds each century. (Feel free to think of it as "mutual attraction" not gravity if my previous statements made you uncomfortable with that word.)
Let's put that into perspective. In the time of the dinosaurs the day was only 23 of our hours long. (You don't suppose they had a dinosaur version of Rodent Race that caused the dinos to die off.)
Speaking of things that slow earth's rotation, even the weather can do it. El NiÃ±o winds can cause earth's rotation to slow by a fraction of a millisecond over just 24 hours.
Technology can do better than that. In 1972 atomic clocks in more than 50 countries were made the final authority on matters of time. They're so accurate that they lose about a second in 31.7 million years. But in 31.7 million years our day will be a half hour longer, so won't all our atomic clocks be wrong?
Actually, no. To keep the clocks in synch with earth's rotation we now add a "leap second" every few years. The most recent leap second was added this past New Year's Eve. (I thought 2009 seemed longer for some reason.)
One clock does even better than the network of atomic clocks. The clock at the National Institute of Standards and Technology, in Boulder, Colorado, measures the vibrations of a single atom of Mercury and is accurate to less than one second of loss in one billion years. (Who knew an atom of mercury could shiver that long?)
We think of timekeeping as standard now. In fact we call it Standard Time. Until the age of trains that had to meet set schedules in the 1800s, every village had its own version of standard time. They used solar noon in their respective areas. As odd as it seems now, a few watches were made in those days of confused standard times for trains that kept track of two times, one the local standard time and the other "railway time."
The U.K. adopted Standard Time first through an act of Parliament. The U.S. came on board on November 18, 1883. Some people speculate that the adoption of Standard Time may have prompted Einstein to think about how space and time might be united in his theory of relativity.
Einstein said that gravity affects the passage of time. So a passenger in an airplane, flying where gravity is weaker, would age a few nanoseconds more than a person who kept his feet on the ground.
Quantum theory claims that the shortest possible period of time (known as Planck time after the German physicist whose work began the whole study of quantum theory) is 0.0000000000000000000000000000000000000000001 second.
Most scientists today believe that time as we know it began with the Big Bang, created with the rest of the universe 13.7 billion years ago. If you care, stay tuned because that belief could change any time now.
Will time ever end? Three Spanish scientists claim it will. They say our expanding universe is not really expanding at all. Rather time is slowing down, making it seem to us as if the universe is expanding. According to their calculations, time will eventually stop, at which point everything we know will stop as well. (I was going to calculate when that would be, but I don't have time.)
Bill Allin is the author of Turning It Around: Causes and Cures for Today's Epidemic Social Problems, a guidebook for teachers and parents who want their children to develop all aspects of their lives at the right time.
Learn more at http://billallin.com
[Primary source: Discover, March 2009]