NIST Builds A 100,000 Times Better Atomic Clock

J Shumate writes: " NIST has built a better clock, which, no doubt, will lead to a better mouse trap." According to the article, "The new all-optical atomic clock -- so named because of its reliance on laser technology -- measures the shortest intervals of time ever recorded. In fact, those intervals are 100,000 times shorter than those observed by the best current clocks."

Comments

Re:Electronics?

[Anonymous Coward]

The effect to which you are referring (clock rates differ between ground and up in the air) is not a special relativity problem (i.e. relative speeds), but a general relativity problem. The clock rates differ because the one on the ground is deeper into the gravity well created by the earth's gravitational field. Such measurements were carried out in the early 1960's using Mossbauer effect driven clocks (that can resolve time durations down to about a part in 10^13 or so).

One would think that a claim to high precision would take this effect into account since gravitational wells do effect photons (light) - an effect first seen in the eclipse of 1919 (Einstein's great vindication).

Short Term vs. Long Term Stability

[Detritus]

Anyone know what the short term stability of this clock is? Last time I checked, masers beat cesium beam clocks for short term stability, which is important in some applications.

Re:accuracy

[thogard]

Pi seconds is about a nanocentury.

Re:Electronics?

[eclectro]

The Reuters report mentions that it takes up a couple of rooms. I would think that it takes pretty exotic equipment to constantly suspend the single ion of mecury so they could bounce lasers of from it.

I'm sure someday they will get all the laser/optical processing smaller, but it is probably isn't a priority right now. The most important use of accurate clocks will come from the PARCS project.