On Sat, 23 Jun 2012 09:09:42 -0700, Jeff Liebermann
wrote:

On Fri, 22 Jun 2012 17:10:12 +0000 (UTC),
wrote:

Why do all the atomic clocks require batteries?

I think you mean WWVB 60KHz clocks. Atomic clocks are cesium and
rubidium standards.

SNIP
Can Americium be used to build an atomic clock? I understand a little
about how cesium and rubidium atoms are used to build atomic clocks
but since Americium is used in many smoke detectors wouldn't that be a
great science fair project or a Maker Faire project? The world's first
truly atomic wall clock? Of course, I suppose it could be argued that
radium on clock hands qualify the clock as atomic if radioactivity is
the only metric.
Eric