Watch CBS News

From Sundials To Cell Phones

CBS News Correspondent Lee Cowan reports on time and its watchers.



Perhaps it's no coincidence that the thousands who cram into New York's Times Square every December eventually look up -- lifting their bloodshot eyes to the night sky to ring in the New Year.

Long before that sparkling ball dropped through the darkness, looking up into the heavens was our best way of telling time.

"If you think back to times when people weren't distracted by neon lights, television, street lights, the sky was the greatest show on earth," says science writer Dava Sobel, whose books include "The Planets," "Galileo's Daughter," and "Longitude."

Measuring the dance of light across the heavens, she says, was a daily challenge both magical and necessary.

"When the world was lit only by the sun, the moon, the planets and fire," says Sobel, "there was no better way to reckon time."

We could easily experience the solar day, measured from one sunrise to the next.

Then there was the lunar month: the length of time it took the moon to become full again.

And when the seasons came full circle again, we witnessed the passing of a solar year.

"The natural time divisions don't naturally mesh neatly with each other," says Sobel. "In trying to combine them, we wind up with things like 'Thirty days hath September, April, June and November.' "

And that's where we were for thousands of years. We had no concept of minutes or hours - let alone seconds.

For more on that, we turned to William J. H. Andrewes, an expert in the history of scientific instruments and time measurement who collaborated with Sobel on "The Illustrated Longitude," which includes the history of the chronometer, a clock that keeps precise time at sea.

Almost as long as he can remember, Andrewes has been studying time and every conceivable way of measuring it.

"I became interested in clocks when I was about 16 years old," says Andrewes, admiring the craftsmanship on a nearby timepiece.

Officially he's a horologist - the traditional name for a clockmaker.

He's also a scholar who has taught at Harvard University.

Man's pursuit of time, in Andrewes' view, is the pursuit of heavenly perfection.

"If you graduate from college and get a 99 percent, you get the highest honors. If you're a clockmaker and your clock is 99 percent accurate, you've failed," he observes.

Stonehenge was accurate to within a month or two, with its stones arranged to measure only the seasons.

By 1500 B.C., the Egyptians had narrowed it down to the day: splitting it into a dozen equal parts, twelve for daytime and twelve for at night.

They used a sundial to mark the intervals in sunlight and water trickling out of a vase to mark the intervals at night.

It was called a water clock and it became the first time measuring device that didn't depend on the heavens.

But they all had their problems.

"If you rely on a sundial, it's not going to work when there are clouds," says Andrewes. "If you rely on a water clock, it's gonna freeze in winter."

So really we can blame the invention of the clock on bad weather? Cloudy skies and cold temperatures?

"You know, this is how these things come about," says Andrewes.

By the 13th century, life was getting crowded in Europe. Urban populations were growing and so was the Roman Catholic Church, whose many orders of monks and nuns could make good use of a mechanism to alert them to their daily duties.

"Time became more crucial," notes Andrewes. "What time should you pray? What time should you eat? What time should you work?"

Medieval headscratchers eventually came up a device called an escapement, which was so revolutionary for the time that it was the technological equivalent of putting a man on the moon.

The device controlled the rotation of a toothed wheel and transmitted that energy to an oscillating bar that moved back and forth.

A simple concept - devilishly hard to put into practice - allowing a bell to be rung at the same time every day.

Very handy for the faithful committed to prayers especially for various times of day.

The new timing device soon had a name that has stuck to it ever since.

The word "clock," says Andrewes, comes from the Latin word clocka, meaning a bell, because the earliest mechanical clocks were bell-striking devices.

As rudimentary as they were, they changed everything. Andrewes says suddenly people became "time conscious" -- "time was money" -- and people began asking and answering questions that would affect everything from manufacturing to farming: What is a workday? It is from sunrise to sunset, or do you do it by the hour? And then how are you going to divide the hours? How are you going to divide the day? Where do you begin the day?

The more precise time measurement got, the more pointed those questions got. And nobody answered more of them than Christian Huygens, a Dutch scientist who took the workings of the mechanical clock and turned them on their side, becoming the inventor of the first pendulum clock, unveiled on Christmas Day in 1656.

"The early mechanical clocks would keep time to within about 15 minutes a day. The pendulum clock could keep time to within a minute a week," says Andrewes. "So it was an enormous advance."

An extraordinary advance from a scientific standpoint and also from a social standpoint.

The clock, says Andrewes, began to be seen as a symbol of wisdom, goodness, temperance, industriousness, and even power.

Especially if you could build a clock to solve one of time's trickiest brainteasers.

Sailors could find their latitude by using the stars and the sun. But judging longitude was different.

"In order to determine longitude," explains Sobel, "you have to know what time it is in two places at once. That's the tricky part."

That involves measuring time at sea - and for centuries, no one had a clock that could reliably do that on the deck of a pitching ship.

Think about it: every daring sea crossing was in the end a matter of both skill and chance.

"The problem of longitude was so important," says Sobel, "that [in 1714 the British] parliament enacted a law offering £20,000 to anyone or any group of people from anywhere in the world who would come up with either a gadget or a technique that would work. They were desperate!"

John Harrison - a carpenter and self-taught clockmaker - finally came to the rescue with a modified escapement using a spring and balance wheel instead of a pendulum, to avoid sensitivity to weather and waves.

It kept time in rough seas to about one fifth of a second per day: ten times better than was required to win the prize.

Now time could be told the world over, with clocks all set by using high noon as a guidepost.

But as the world spun and decades passed, another problem presented itself: noon was slightly different for everybody.

Now that was no problem when folks were creeping across the country in a stagecoach. But when the railroads started rushing people from city to city, well, scheduling became a mess.

To standardize time, the United States established four time zones in 1883 and by the following year, the entire globe had 24 time zones - all set to Greenwich mean time.

After the steam age came the jet age, and sure enough, clocks still weren't accurate enough - not for scientists anyway.

So they came up with this: the atomic clock. The latest model is only off by a single second every 20 million years.

Atomic clocks don't tick or tock. Instead, they measure the regular vibration of atoms: the cesium-133 atom to be exact.

Turns out those regular vibrations are even more regular than the heavens themselves. For the first time, scientists could prove the earth's orbit is not constant and if we were really going to keep our clocks timed to the heavens, we needed to add a second from time to time to make up for the Earth's timely transgressions.

"The problem is, we still live on earth, we still go around the sun, and we still see the moon," says Sobel. "So no one wants those things to get too far out of synch with atomic time."

Which is why we all celebrated New Year's one second later last night. Adding that "leap" second put us all back on track.

Still, no matter how we measure it, chasing time remains an ageless daily dilemma for all us. Perhaps that's why time always seems so fleeting - and why we never seem to have enough of it.

The sundial featured in this piece was designed by William J. H. Andrewes and is located at the Pomfret School.

By Lee Cowan

View CBS News In
CBS News App Open
Chrome Safari Continue
Be the first to know
Get browser notifications for breaking news, live events, and exclusive reporting.