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Atomic clocks are used for international time distribution services as they are the most accurate frequency and time standards. Atomic clocks control the wave frequency of television broadcasts and global navigation satellite systems such as GPS (Global Positioning System) with 24 satellites orbiting the earth, each one carrying a precise atomic clock.
Hand-held GPS can detect accurate latitude, longitude, and altitude reaching 15 meters and local time to 50 billionths of a second. Other than military uses, GPS is used in airplane navigation, sailing, wilderness recreation, oil exploration, and interstate trucking, to name a few.
Radio-controlled watches, on the other hand, have a radio inside where an atomic clock is located. It receives the signals with a margin of error of one second every 100,000 years. The 38 microseconds per day offset in satellite clocks rate is immense and could cause navigational oversight that can accumulate 100 km per day.
Atomic Clock Precision
Atomic clocks’ worldwide use is to calculate time to precision with a margin of one-second error every hundred million years. Newer versions that measure optical frequencies of light are even more precise and may eventually replace the radio-based ones.
In the absence of relativity, and without the proper application, the GPS will fail its navigating capacity within two minutes. Next time your plane approaches the airport in stormy weather, think about Einstein and the GPS tracker to help the pilot guide the aircraft to a safe landing.
According to Einstein’s theories, people age one billionth of a second less every year than those who live on top of Mt. Everest because of the gravitational time dilation phenomenon. The science behind this phenomenon is that the gravitational field warps the spacetime creating gravity. So, when a stream of light particles pass an object with enough pull, a stream of photons traveling at the speed of light appears to bend, causing it to move faster or slower depending on the enormity of the object and the gravitational pull.
The atomic clock is like the regular clock that keeps time according to oscillation. For example, in a pendulum-driven grandfather clock, the back and forth movements are more or less accurate. In an atomic clock, the atom is causing the vibration at the same frequency with incredible stability and synchronization, maintaining a margin of 1 billionth of a second error.
Today, the best clocks can predict earthquakes and discover new physics.
Written by Janet Grace Ortigas
Edited by Sheena Robertson
Science News: An atomic clock measured how general relativity warps time across a millimeter; by Emily Conover
Asiana Times: The General Theory of Relativity on a millimetre scale; by Sureshkumar M
Featured and Top Image Courtesy of Nate Phillips’s Flickr Page – Creative Commons License
Inset Image Courtesy of Alex Berger’s Flickr Page – Creative Commons License