Most Accurate Clock Ever

by Fraser Cain on March 9, 2012

An atomic clock; a relic of a bygone age? Image credit: NIST

An atomic clock; a relic of a bygone age? Image credit: NIST


Do you find that you’re always having to adjust the clocks in your house? Why can’t someone just make a clock that’s accurate? How about a clock that would never lose time in, say, the entire age of the Universe? Well, that’s just what researchers from the University of New South Wales are proposing.

According to their calculations, a neutron orbiting around the atomic nucleus of an atom would do the trick. In fact, this “atomic clock” would be so accurate, it wouldn’t gain or lose 1/20th of a second in 14 billion years – that’s the age of the Universe.

Obviously a clock like this wouldn’t have any value for home use, but in science, accurate clocks are everything. And this single atom clock would be 100 times more accurate than anything scientists have access to right now. They’d be able to record time down to 19 decimal places: 0.0000000000000000001 of a second.

One of the most important places that clocks are used is GPS. The Global Positioning System uses clocks to time how long signals take to reach your GPS unit from various satellites. The satellites are broadcasting very accurate times, which can then be used to triangulate your position. More accurate clocks mean more accurate position.

So how exactly would they do it? Lasers, of course. All the cool science is done with lasers. According the researchers:

“Atomic clocks use the orbiting electrons of an atom as the clock pendulum. But we have shown that by using lasers to orient the electrons in a very specific way, one can use the orbiting neutron of an atomic nucleus as the clock pendulum, making a so-called nuclear clock with unparalleled accuracy.”

Here’s the trick. The neutron of an atom is so tightly bound to the nucleus that it’s almost completely unaffected by outside forces. Electrons, on the other hand, can be affected and so the clocks can be less accurate.

Source: UNSW News Release

About 

Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay.

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