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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."
until it comes with indiglo i don't want it
Eventually you'll be so accurate that walking by the thing will cause enough relativistic distortions that you can no longer claim to have any accuracy at all.
You kidding me? The prospect of GPS-guided bullets accurate to the millimeter will have the US military pursuing this in next-gen GPS satellites as soon as the technology is viable. Hell, this'll be the most valuable update to military hardware in decades.
Viable Slashdot alternatives: https://pipedot.org/ and http://soylentnews.org/
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http://arxiv.org/abs/1110.2490
And here I was, thinking that neutrons were inside the nucleus and electrons were orbiting around it. What's going on here? How can a neutron orbit a nucleus? It's an actual question, I know the atomic models I was once taught are way out of date (by a couple of centuries, probably), but I never heard of neutrons orbiting nuclei.
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...
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
Nothing. Modern physics is unable to describe how electrons really work/interact with other subatomic particles in a way that makes sense. Which the orbiting isn't right, the shell model isn't right either...we're just not able to describe it yet. So, one model can be an effective description for certain purposes and others for others. In this case, the Nuclear Shell Model describes a different model of the atomic nucleus that describes the quantum interactions in a manner that allows these types of measurements to be made.
If an atomic clock is your most accurate timepiece then how on earth can you tell if something is more accurate?
Can someone explain?
Also , given that a second is defined in terms of the ceasium atom as used in atomic clocks then surely anything that deviates from this is by definition LESS accurate (if you see what I mean)?
It's about time
A preprint is available on arXiv at http://arxiv.org/abs/1110.2490
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.
Could, could, could, could. Just a method of timekeeping that *could* be used, but has many issues. How about an post on warp drives next?
New discoveries, breakthroughs and technologies have potential until they are actually used. Once they are used then they need to prove the projections correct. By today's "everything changes so fast it's hard to keep up without a clock that's more accurate than an atomic clock" standards these things aren't new anymore by the time they've been proven useful (or useless).
A whole lot of science and engineering needs this. We have communication networks that give us ability to distriute experiments and measurements, but a lot of those aren't very useful without a very precise time reference; the networks, as they are, are quite poor at distributing time. Examples: suppose you want to measure time-of-flight of particles across the globe (neutrinos or otherwise); large base telescope (whether radio or optical); more accurate global positioning. The prerequisite in all cases is an ultra-accurate timebase. In fact, large base optical telescopes will require very stable and accurate distributed local oscillators (heterodynes), lack of one is one of the reasons why we don't have optical-to-RF heterodynes for imaging; RF-to-RF heterodynes, even distributed ones, are nothing new and are used for radioastronomy all the time -- optical ones are hard because you need orders of magnitude better clock source in terms of phase noise and drift.
A successful API design takes a mixture of software design and pedagogy.
I've always wondered, with regard to the accuracy of clocks like this, how can you actually tell how accurate it is?
William of Ockham had no beard. The most likely explanation is that it was chewed off by squirrels every morning.
It's an exciting idea, and it's streaks ahead of 'traditional' microwave transition atomic clocks. These do not represent the state of the art, however, for which one should look at the experimentally demonstrated ~9e-18 accuracy by the Wineland group at NIST http://arxiv.org/abs/0911.4527v2 ; http://www.nist.gov/physlab/div847/grp10/ , or the Strontium ion clocks at NPL (Teddington, UK) Essentially, the higher the frequency, the more clicks you get in a certain time, and the more accurate your clock can be (the smaller an error one missed click would represent). The caesium atomic clock is about 10 GHz (1E10 Hz). Strontium is in the optical, so a few 100THz (1E14). Aluminium ions are at about 1PHz (1E15 Hz). This new proposal with Thorium is around 7.6eV, which is about 2PHz, so not a million miles away from the current, demonstrated, state of the art. Also... orbit of the neutron around the nucleus isn't a fair description of a magnetic dipole transition, which would more accurately be describes as a flip in the direction of the neutron's spin axis. :)
The term "making sense" is, I believe, misapplied here. The quantum world is pretty much unavailable to our senses, neither do they exactly teach this stuff to kindergartners. So we have no early-life experience of any sort here, thus there's no common sense about the world at quantum scale. It won't ever make sense, and there's no reason for it to make any sense. It's just how the world happens to work, and there's nothing at all that we can do about it. This is in stark contrast to, say, bureaucracy, where certain ways of doing stuff are not how Nature works, but how humans happen to work -- very changeable if you can pull it off.
A successful API design takes a mixture of software design and pedagogy.
Can't find one even myself! Sounds like it's no fun anymore :-|
Slashdot, fix the reply notifications... You won't get away with it...
If Server A has 90% uptime and Server B has 99% uptime, that does not mean that Server B is up 10x more than Server A, even though Server A is down 10x more than Server B. In fact, Server B is only 10% better than Server A. Or, 1/10 as bad.*
So, while the old clock may drift 100x more than this new one in a certain amount of time, or this new one might last 100x longer before drifting a certain amount (or whatever--the .au article is total puff and I don't care enough to look at the source), it is almost certainly not 100x more accurate. At best, it's 1/100th as inaccurate.
* The difference between 36 days of downtime per year versus 4 days might be the difference between "useful" and "completely worthless", making Server B 100x better, but that's not what we're measuring here.
Dear Slashdot: next time you want to mess with the site, add a rich-text editor for comments.
Yes, because being off by 2 seconds every billion years is something to worry about. I am sick of having to adjust my watch for the inaccuracy of atomic clocks.
a OC-192 fiber line transmits 10 gigs/sec, roughly.
If you stuck one of those "2 secs/gigayear" clocks on each end, instead of regenerating the clock off the line, I think the circuit would lose line sync and drop every:
365*24*60*60 /10 /2 / 6/60/60/24 = every 18.2 days. Bummer.
Lets check. 10 gigabits/sec at 18.2 days is 18.2*24*60*60*10*1e9 is 1.57e16 bits. 2 secs/gigayear is an error rate of 1e9*365*24*60*60/2 is 1.57e16 bits per clock framing failure. Seems likely.
That is why now a days you get your clock off the line instead of internal clocking at each site. In ye olden T-1 era, a clock that good at each CO would mean you'd probably never experience a clock slip between COs in the lifetime of the equipment... Even in ye olden days we internal timed quite a bit (and some of our DEXCS only could do internal, so we had to)
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
So, honest question, how do you measure the accuracy of the world's most accurate clock? I mean, what do you measure it against?
I don't see it as a paradox at all. Wave/particle duality invariably involves waves when you're integrating over time and particles when taking instantaneous views. We know from things like quantum tunneling that the particle can exist anywhere along the wave function but we also know that it can only exist at SOME point along the wave function at any given time - it does not exist everywhere.
Heisenberg's Uncertainty Principle is ultimately a property of information theory, not physics, but it helps that particles can only exist with position (not velocity) and waves can only exist with velocity (not position), since this gives you what you want.
(Aside: This, to me, proves the primacy of maths - the physics isn't just modeled by the maths but is the way it is because the maths won't let it be anything else.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)