TAI zone?

[Paul Koning]

On Jul 1, 2011, at 1:31 PM, David Magda wrote:

> On Jul 1, 2011, at 13:21, Paul Koning wrote:
> 
>> 
>> On Jul 1, 2011, at 1:16 PM, Guy Harris wrote:
>> 
>>> If you care *that* much, you need something fancier, e.g. an atomic clock. :-)  I seem to remember some news article in the past year or so indicating that there might be some new type of atomic clock coming out that would be less expensive, but I can't seem to find it with some simple Googling.
>> 
>> There was a new clock that's particularly compact (an inch or so max dimension).  It wasn't clear just how it works, but it sounded like it's comparable in stability to a rubidium clock.
>> 
>> In the meantime, I think the cheapest atomic time source is a GPS box.
> 
> Probably related to this:
> 
>> Now an atomic clock-on-a-chip is available that is the result of 10 years of government-funded research and development. The chip is not cheap — $1,500 — but it costs less than conventional atomic clocks and the price is sure to go down as manufacturing gears up to meet demand from military applications.
> 
> 
> http://science.slashdot.org/story/11/05/11/1745213/

Thanks, yes, that's the one I was thinking about.

Interesting article.  It says that the active medium is cesium, but then mentions a resonant frequency that is not the one used in the definition of the second.  So either the author is very confused and pulled a random number out of the air, or we're dealing with a different resonance than the standard one.  In that case, it is entirely unclear how stable it is.  It might be similar to the one used in the definition of the second, or it might be very different (like rubidium, or worse).

	paul