Scientists have set a new record in accurate timekeeping, by creating a new atomic clock that won't lose or gain a second in 15 billion years. This timespan is greater than the estimated age of the Universe itself.
The clock measures the oscillation of strontium atoms to create its "tick" and could one day become the standard for Coordinated Universal Time (UTC), the standard for the world's official time. Currently, UTC is set by atomic clocks that measure the vibrational frequency of the element caesium, although these are only accurate in the neighborhood of one second in hundreds of millions of years.
This new strontium clock was developed by physicists from the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder, and measures the movement of strontium atoms pinned in a narrow column of powerful lasers. All atoms have a naturally consistent vibrational frequency with strontium it is about 430 trillion times per second. The measurement of these movements is what scientists used to create the clock.
The strontium clock, also known as an optical lattice clock, has been in development for several years and already broke timekeeping records in 2013. However, scientists have made several tweaks that they outlined in the journal Nature Communications that include shielding the clock from types of electromagnetic radiation that have made the new timekeeper three times more accurate. The clock is so accurate that just raising it just two centimeters off of the Earth's surface has a noticeable effect. Even with this small change in Earth's gravity from raising it, the clock can detect it and maintain accurate time.
The creation of this clock is about more than just bragging rights among scientists. It could actually help researchers create the most accurate maps of the shape of the Earth. The effect of gravity on the passage of time was first predicted by Albert Einstein as part of his theory of relativity. This essentially means that clocks tick at different speeds based on their elevations.
Scientists believe they can harness this phenomenon by using a network of these highly accurate clocks spread across the surface to measure its shape. This new concept of measuring the Earth using these clocks has been given the name, relativistic geodesy.
However, the strontium clock is still not accurate enough to beat more traditional methods of measuring the shape of the Earth. In order for it to be useful, scientists believe that it would need to detect an elevation difference of just one centimeter. For now it seems, the scientists responsible will have to be satisfied with creating the most accurate clock ever made and be happy with some of the other benefits it could provide including improved navigation and positioning systems and pushing the boundaries of quantum physics.
