• Nuclear clock could steal atomic clock's crown
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[release] ATOMIC clocks are the basis of GPS devices, they define the official length of the second and recently played a role in tracking [URL="http://www.newscientist.com/article/mg21128322.900-lightspeed-neutrinos-point-to-new-physical-reality.html"]subatomic particles that seemingly travelled faster than the speed of light[/URL]. Now this [URL="http://www.newscientist.com/article/mg21128331.400-about-time-the-worlds-most-accurate-clock.html"]"ultimate" timekeeper[/URL] has a rival: a new method for making nuclear clocks suggests such devices could be 60 times as accurate as their atomic rivals. A nuclear clock has not yet been made but the idea would be to use the atomic nucleus like a tuning fork. A nucleus will jump to a higher energy state, then fall back down, and jump up again, only if it is hit with a very specific frequency of light. Tuning a laser so that it prompts these jumps is a way to set its frequency with a phenomenal level of precision. The frequency can then be used like a clock's tick to keep time. A similar method is used in atomic clocks, except it is the electrons orbiting the nucleus that make the energy jump. The [URL="http://www.newscientist.com/article/mg21128331.400-about-time-the-worlds-most-accurate-clock.html"]most accurate atomic clocks[/URL]drift by an amount equivalent to just 4 seconds since the big bang. In principle, a nuclear clock could smash that. Ambient electric and magnetic fields affect electrons in atomic clocks, causing errors, but they would influence the tightly bound particles in the nucleus much less. While [URL="http://iopscience.iop.org/0295-5075/61/2/181/"]nuclear clocks made from thorium atoms[/URL], which can be excited with relatively low-energy ultraviolet light, were first proposed in 2003, whether they would actually be more accurate than their atomic rivals was unclear. The exact frequency needed to excite a nucleus depends on the configuration of its orbiting electrons, which can vary, introducing uncertainty. Now [URL="http://kuzmichlab.gatech.edu/coreycampbell.php"]Corey Campbell[/URL] at the Georgia Institute of Technology in Atlanta and colleagues have devised a scheme that uses lasers to [URL="http://arxiv.org/abs/1110.2490"]carefully control the spatial orientation of the electron orbits[/URL] in atoms. A thorium clock controlled in this way would drift by just 1 second in 200 billion years, the team claims - that is more than 14 times the age of the universe (arxiv.org/abs/1110.2490). "They show that indeed these [drifts] can be very small or even negligible," says [URL="http://www.questhannover.de/en/members/pd-dr-ekkehard-peik/"]Ekkehard Peik[/URL] of the National Metrology Institute of Germany in Braunschweig, who is not a member of the team. Before nuclear clocks become a reality, researchers must identify the precise frequency of light needed to excite thorium nuclei. Such clocks could shed light on [URL="http://www.newscientist.com/article/mg19526121.200-string-theory-the-fightback.html"]string theory[/URL]. The frequency of the jumps in a nuclear clock will depend on the strong nuclear force, while the jumps by electrons in atomic clocks depend on a different fundamental force. So together they could [URL="http://www.newscientist.com/article/mg21128194.000-one-step-closer-to-a-nuclear-timekeeper.html"]reveal if the relative strength of the forces changes[/URL], as string theory has it.[/release] [URL]http://www.newscientist.com/article/mg21228374.500-nuclear-clock-could-steal-atomic-clocks-crown.html[/URL]
That's very accurate.
kinda understood this. This is good.
This was very informative and I learned a good bit about... Clocks.
I wonder when we'll reach the very limit of accuracy
Slow news day.. [editline]7th November 2011[/editline] AUTOMERGE [editline]7th November 2011[/editline] Still interesting though.
Nuclear...Atomic... Hey man, what time is it. It's half past- [t]http://1.bp.blogspot.com/_wCKvyY56maw/S-jacPZumDI/AAAAAAAAAAM/svTadQJUDcU/s1600/atomic-explosion.jpg[/t]
This is great, I got sick of having to reset my clock every couple thousand years.
It's weird... Assuming infinite time, even thorium clocks will drift infinitely.
Can't wait for Fox news to claim that they leak radiation or some crazy shit
While this is really cool and all, it's role as a clock (from what I understand) will be in the shadow of it's potential role as a research tool. "Interesting" most certainly is an understatement. :P[QUOTE=minilandstan;33178048]Nuclear...Atomic... Hey man, what time is it. It's half past- *pew pew*[/QUOTE]Unfortunately the world doesn't work like that.
Skipped right over that Hydrogen Clock I'd been planning. Might be able to seal the deal on the Anti matter clock though.
[QUOTE=Armyis1337;33178335]It's weird... Assuming infinite time, even thorium clocks will drift infinitely.[/QUOTE] The drift over long timescales isn't the issue. It's more about how many trillionths of a second drift per year, because a great deal of modern technology requires accurate time resolution.
I have to add something to the article: Sure, it is a good thing having a new way of creating a frequency standard. It even is supposed to be better as the current best [u]microwave[/u] frequency standards like the NPL-CsF2 Caesium fountain clock. But as I noted it's [u]microwave[/u] based, they are underlay fundamental physical limits, especially the low interrogation frequency (of 9.2 GHz). Optical frequency standards on the other hand promise (several 100 THz, so 5 orders of magnitude greater = 100000 greater frequency) a much better stability and e.g. state-of-the-art optical strontium lattice clocks even surpass every microwave based atomic clock right now in terms of stability and accuracy. In my honest opinion, the new SI-definition of the second will be based on cold neutral atoms or ions which are interrogated optically by a laser. Give this a read if you want to know minimal basics of optical atomic clocks: [url]http://www.rp-photonics.com/optical_clocks.html[/url] [editline]8th November 2011[/editline] [QUOTE=Contag;33179033]The drift over long timescales isn't the issue. It's more about how many trillionths of a second drift per year, because a great deal of modern technology requires accurate time resolution.[/QUOTE] Do not mix up instability (as drifts count to that) with accuracy (how good can be resolve the frequency, e.g. by averaging for a long time). Those are totally different things. Also having "drifts" of seconds in trillion of years can be translated to "drifts" in a year though. Here is a good picture how to distinguish accuracy and stability (taken from Riehle - Frequency Standards): [img]http://puu.sh/8jJy[/img]
That's much better than my watch which gets faster by a minute every 4 months.
[QUOTE=aVoN;33180294]I have to add something to the article: Sure, it is a good thing having a new way of creating a frequency standard. It even is supposed to be better as the current best [u]microwave[/u] frequency standards like the NPL-CsF2 Caesium fountain clock. But as I noted it's [u]microwave[/u] based, they are underlay fundamental physical limits, especially the low interrogation frequency (of 9.2 GHz). Optical frequency standards on the other hand promise (several 100 THz, so 5 orders of magnitude greater = 100000 greater frequency) a much better stability and e.g. state-of-the-art optical strontium lattice clocks even surpass every microwave based atomic clock right now in terms of stability and accuracy. In my honest opinion, the new SI-definition of the second will be based on cold neutral atoms or ions which are interrogated optically by a laser. Give this a read if you want to know minimal basics of optical atomic clocks: [url]http://www.rp-photonics.com/optical_clocks.html[/url] [editline]8th November 2011[/editline] Do not mix up instability (as drifts count to that) with accuracy (how good can be resolve the frequency, e.g. by averaging for a long time). Those are totally different things. Also having "drifts" of seconds in trillion of years can be translated to "drifts" in a year though. Here is a good picture how to distinguish accuracy and stability (taken from Riehle - Frequency Standards): [img]http://puu.sh/8jJy[/img][/QUOTE] Why is a) not precise?
[QUOTE=Lazore;33181604]Why is a) not precise?[/QUOTE] It is, the descriptions are before the letters.
Fucking ninjas
*already answered* (ninja'd too)
I misread the title as Nuclear Cock could steal Atomic dock's crown but anyway, the nuclear clock sounds expensive
I can buy them a cheap digital clock instead so they can save some money.
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