Friday, July 31, 2009

Keeping Time

I always assumed that our clock time that we live by has been around for hundreds of years. Well, I found out it’s more like just over a hundred years.

Until the 1800’s, every village in the United States lived in its own time zone with all of the clocks synchronized to the solar noon. With the advent of trains this created mayhem trying to keep on a schedule. For years watches were made that could tell both the local time and “railway time.” It wasn’t until 1883 that American railway companies forced the adoption of national standardized time zones.

One second used to be defined as 1/86,400 the length of a day, but Earth’s rotation isn’t completely reliable. Tidal friction from the Sun and Moon slows our planet and increases the length of a day by 3 milliseconds per century. This means that during the time of the dinosaurs a day was just 23 hours long.

Weather also changes the day. During El Niño events, strong winds can slow the rotation of the Earth by a fraction of a millisecond every 24 hours. To keep time in sync with the Earth’s slowing rotation, a “leap second” is added every few years. The last time a “leap second” was added was on New Year’s Eve of 2009.

The world’s most accurate clock is at the National Institute of Standards and Technology in Colorado. It measures vibrations of a single atom of mercury. In a billion years it will not lose one second.

Daylight savings time was started by Ben Franklin. He spent a lot of time in France and realized that their later nights and sleeping in in the mornings used more resources, namely candles. Daylight savings times was implemented to utilize more daylight hours and conserve resources. The amount of money saved since it started is incalculable. Today, the Department of Energy estimates that electricity demand drops by 0.5 percent during Daylight Savings Time and save the equivalent of almost 3 million barrels of oil daily.

Interesting Facts: According to quantum theory, the shortest moment of time that can exist is known as Planck time, or 0.0000000000000000000000000000000000000000001 second • Einstein showed that gravity makes time run more slowly, thus airplane passengers, flying where Earth’s pull is weaker, age a few extra nanoseconds each flight

Now you’re a little smarter, Girlfriend — And so am I.

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