Atomic clocks usually use types of radiation to drive super accurate timekeepers but a new clock technology built at the University of Western Australia might put them all the shame. The clock, developed by Andre Luiten, uses a cold sapphire crystal to create an oscillator that is millions of times more precise than a standard cesium-133 clock.
The system uses a tiny sapphire crystal that can maintain its oscillations longer than cesium atoms can in the wild. Because the sapphire won’t break down over time, you can make the device far more precise than previous solutions. From Spectrum:
But for some applications, accuracy is less important than precision. Precision has to do not with delineating the perfect second but rather with creating extremely regular ticks, or oscillations. Imagine a game of darts. Atomic clocks are able to land all their darts, or oscillations, broadly around the bull’s-eye so that the average position is right on target, even though any given dart might be a centimeter or two away from dead center. Luiten’s device doesn’t aim for the bull’s-eye: instead, it is able to land all its darts at exactly the same point on the dartboard. In other words, each tick is really, really, really just like another.
To achieve very high precision, Luiten needed to find a material that could sustain electromagnetic oscillations for longer than a beam of cesium atoms can. Another way of putting this is that he needed a crystal with a greater spectral purity, one that would respond only to an exceedingly narrow range of frequencies, almost like a low-loss guitar string that can vibrate for an extremely long time and thus at a very pure frequency.
The benefit of this solution is not its accuracy – that’s a given – but in its precision. Because every “tick” is exactly like every other, the sapphire clock won’t waver from its mission of telling the time. Cesium, on the other hand, has a number of drawbacks but because each vibration – 9,192,631,770 of them per second, to be exact – is fairly uniform it has become the de facto standard for timekeeping. Sapphire, on the other hand, ticks perfectly, allowing for more precise timekeeping.
I doubt we’ll be seeing sapphire watches any time soon but it’s nice to know there’s something that can knock atoms off their lofty timekeeping perch.
