Single-Ion Clock 100 Times More Accurate Than Atomic Clock

New submitter labnet writes with this excerpt from news.com.au: "University of New South Wales School of Physics professor Victor Flambaum has found a method of timekeeping nearly 100 times more accurate than the best atomic clocks. By using the orbit of a neutron around an atomic nucleus he says the system stays accurate to within 1/20th of a second over billions of years. Although perhaps not for daily use, the technology could prove valuable in science experiments where chronological accuracy is paramount, Prof Flambaum said."

Link to actual paper

[foo1752]

http://arxiv.org/abs/1110.2490 [arxiv.org]

Re:Eventually...

[gomiam]

It's even worse. IIRC, current atomic clocks are now so precise that stacking one on top of the other (say 20cm distance) is enough to make them start drifting due to the different gravitational field strength.

Re:Orbit of neutron around the nucleus?

[CaptainJeff]

Here you go. Nuclear Shell Model [wikipedia.org]

If You Need That Much Accuracy

[Greyfox]

It's very easy to fuck it up, as we saw with the FTL neutreno experiment a few months ago. I've seen a lot of business requirements specify that level of precision because they think it would be cool and it just turns into a nightmare later. Hell, you're lucky to agree within tens of seconds. Take POSIX (PLEASE! Heh.) POSIX specifies that time measured in seconds from midnight, Jan 1, 1970 UTC. Seams easy enough right? Well it turns out UTC specifies accounting for leap seconds, so you should subtract 33 seconds (IIRC) over the course of those 42 years. POSIX also specifies that leap seconds not be accounted for. Brilliant! Then it's not UTC! Now here's where it gets fun! The Linux kernel may or may not actually handle leap seconds, depending on how you configure it. And what happens if you're syncing off NTP? Or GPS? It's a problem if you need to convert to TAI or TDT. If you adjust for leap seconds and your system doesn't measure them, you could end up being over 60 seconds wrong versus what time it "really" is. When you're trying to communicate with a satellite going 2000 miles a second, that's a problem. Because you'll be pointing you're antenna over there, and the satellite's really over here!

It'd be nice if some physics professor *cough* could solve those problems before making some shit that can be accurate for a billion years! See what I did there? That was just passive aggressive right there, wasn't it? Too much Portal, lately...

Re:Eventually...

[huge]

As the old saying goes: "A man with one clock knows what time it is. A man with two clocks is never sure."

Preprint on arXiv

[eis2718bob]

A preprint is available on arXiv at http://arxiv.org/abs/1110.2490 [arxiv.org]

A nuclear transition in triply-ionized 229Th has been found which is particularly insensitive to external magnetic fields and electron configuration, which gives the potential for a very stable clock,several orders of magnitude better than current clocks if phase comparisons can be made across a scale of days or weeks. The transition energy is at 163nm (in the ultraviolet). To take advantage of this clock an extremely stable laser at this wavelength (using current best clocks) will need to be created.