It’s About Time: The Clock that Keeps the Entire US Ticking

Linda Davidson / The Washington Post via Getty Images(WASHINGTON) — You may be looking forward to catching an extra hour of shut-eye this Sunday as most of the country prepares to roll their clocks back an hour for Daylight Saving Time, but have you ever wondered where time actually comes from?

ABC News/Yahoo! News ventured to the U.S. Naval Observatory in search of answers.

Situated atop a hill overlooking much of Washington, D.C., the observatory is perhaps best known as the home of the vice president’s mansion, but it is also home to the nation’s master clock.

Every time you turn on your cellphone or plug an address into your car’s GPS, you are actually communicating with the Naval Observatory.

“Everything is tied in to the master clock here,” Naval Observatory’s Public Affairs Officer Geoff Chester explained during a recent tour. “So, if you use anything that remotely touches GPS as a timing source, then you are essentially getting your time from us.”

Chester explained how the job of keeping the nation on time is a whole lot more complicated than counting up from “one-Mississippi.”

“We now use a particular frequency of an atom,” Chester said. “It’s essentially a microwave resent frequency, and a second is now defined as the interval of 9,192,631,770 hyperfine transitions of the ground state of a neutral caesium 133 atom.”

The 9,192,631,770 atomic intervals that measure a second is the basic building block of time as it is measured today.

In addition to watching the clock, the Naval Observatory has long played a role in keeping an eye on the sky. Chester showed ABC News/Yahoo! News a telescope that was built in 1893 to observe a particular type of star called “double stars,” which appear close to each other when seen from Earth.

“Double stars make up about two-thirds of the population of all the stars that you can see in the sky,” Chester said. “So, it’s very important for us to understand how these components of these double stars move relative to each other, so we can properly get our guidance sensors pointing at the right things.”

One of the most interesting aspects of the telescope, which is not computer-controlled as many modern ones are, has nothing to do with the operation of the telescope itself.

If you stand in the middle of the domed room that houses the telescope and look up, there is no apparent way to reach the telescope, which is elevated above at the ceiling’s height — until Chester hits a button and the entire floor begins to elevate to reach the telescope above.

“We believe this is the largest elevator in the city,” Chester said, as the floor made its ascent.

Follow @ABCNewsRadio
Copyright 2014 ABC News Radio