Why cesium?

Good question. A short bit of research tells me that the resonant vibration frequency of a particular isotope of Cesium is known very precisely. The best cesium atomic clocks are accurate to 1 second in 17 million years.

Makes perfect sense – Thanks!

Why not cesium?

Here’s a link that explains it; Cesium Great question. I learn more from this site than I ever would have imagined.

I am so gonna get swallowed up very quickly by the sheer brilliance of you guys and your science… but I am lurking nevertheless… fascinating subject!

The first attempt at an atomic clock was to use the s-p transition of the outer electrons in the beer atom, but that wavelength proved to be highly inconsistent… not so much in its frequency, but it actually staggers.