Keeping Time with a Mercury Atom

Roland Piquepaille writes "The National Institute of Standards and Technology (NIST) has announced that a new experimental atomic clock based on a single mercury atom is now at least five times more precise than NIST-F1, the U.S. standard clock. This mercury atomic clock 'would neither gain nor lose a second in about 400 million years' while it would take 'only' 70 million years to NIST-F1, based on a 'fountain' of cesium atoms, to gain or lose a second. But even if this new kind of optical atomic clock is more accurate than cesium microwave clocks, it will take a while before such a design can be accepted as an international standard. A ZDNet summary contains pictures and more details about the world's most precise clock."

Comments

Re:Only problem is...

[Umbral Blot]

Relativity doesn't make clocks less useful, in fact it makes them more useful (because you can use them to figure out how fast you are going as well). And assuming that the clock remains under constant acceleration there is no reason to believe that relativity would make it less accurate.

Re:400 million years

[evilviper]

It's easy to make impressive statements like that when you know nobody will be around to prove you wrong!

Complete nonsense. This isn't a "prediction", it's a mathematical number/time. Like any other number/time, you can easily convert it into shorter time-frames.

1 sec in 400 million years is ==
    1/2 sec in 200 million years
    1/4 sec in 100 million years
    1/8 sec in 50 million years
    etc.

That means it is accurate to 0.000000025ths of a second in 10 years... A more partical time-frame, which can be tested fairly easily.