Slashdot Mirror
New Atomic Clock 1000 Times More Accurate
stevelinton writes "The UK National Physical Laboratory has a new atomic clock potentially 1000 times more accurate than current cesium clocks: to within 1 second in about 30 billion years!
This could lead quite soon to a new definition of the second, and in a while to improved resolution in GPS successor systems. More interestingly, there are theories that some of the universe's fundamental dimensionless constants may have changed by a parts in a million over the last 10 billion years or so. These clocks are so accurate that they should be able to detect these changes over a year or two."
This could lead quite soon to a new definition of the second
Now all we need is a13 year old to update the wikipedia entry.
Trolling is a art,
My boss will now know with 1000x the accuracy exactly how late I am. Wonderful!
Great.. now I can measure measure how late the train is to an accuracy of a few attoseconds. hehe
The great thing about getting more accurate timing is that it should allow you to measure distances with the same accuracy. I think that by shining two different coloured lasers against a mirror and measuring the beats in the interference pattern of the returned beam it should be possible to measure a metre very exactly.
Anyone know if this is garbage or does more accurate time mean more accurate distance.
Simon.
The accuracy of caesium clocks is one of the factors limiting GPS accuracy to a meter or so. These clocks could get that down to a millimeter allowing, for instance, GPS based automated guidance for trucks and automated landing for planes.
There are also applications in scientific research -- I mentioned detecting changes in fundmental constants in the story, it might also help allow very long baseline interferometry (where two radio telescopes thousands of miles apart obtain the same resolution as one telescope thousands of miles wide) at higher frequencies, pushing into the long IR.
Call me back when there's a portable version available.
of clocks: "I see no progress in this industry. These clocks are no faster than the ones they made a hundred years ago."
Because they're interested in deviations of much less than a second.
trapped ion frequency standards are nothing new, NIST made one years ago, the only difference is that NPL uses Strontium instead of Mercury. While it appears to be more accurate than the NIST one, trapped ion standards are not very practical to build or run for everyday use and its not a primary frequency standard, since the definition of the second is in terms of Cesium resonance, only Cesium clocks are primary frequency standards.
That's all well and good, but I'll bet it still flashes "12:00-12:00-12:00" after the power goes off.
Does anyone know more about this?
Sola Deo Gloria!
The accuracy of the clocks is a small factor in real-time GPS accuracy.
Ionospheric delay plays a much larger role. Survey-grade receivers use both the L1 and the L2 bands in an attempt to better model this delay. Ionospheric delay is frequency-dependent and impacts on the L1 and L2 signals by a differing amounts.
Multipath plays a role also, not as big as the ionosphere, but still larger than the accuracy of the clocks on the GPS satellites.
No, he was right.
Accuracy is how close the measurement is to the actual value, precision is how much often the measurement is in agreement with the value.
Showing the wrong time, no matter how precise, doesn't mean much. The new clock is more accurate.
Slashdot's error -
It's not 1000 times more accurate, it's 3 times more accurate (than the NIST's mercury ion resonator). The figure of 1000 is what they think the technology in the future, but that's purely hypothetical.
NPL's errors -
Bombarding an ion with a blue laser in order to cool it is _in_no_way_ similar to firing a beam of light at a mirror-ball. Mirror balls do not get cooler when you fire beams of light at them. Explanations that use inappropriate analogies are as useful as wearing tie-died lab-coats in night-clubs.
If "one part in 10^18" is "nearly a thousand times more accurate than the best clocks of today", then today's best clocks must be accurate to 1 part in 10^15. Therefore this new clock, being "three times more accurate than the Americans", "3.4 parts in 10^15", cannot be the be the best clock of today. Either that or someone in NPL can't do simple maths.
FP.
Also FatPhil on SoylentNews, id 863
I was thinking the same thing until I actually read the article.
...
An answer from the article that affects everyone and not just super geek physicists:
Navigation on earth - based on a cluster of orbiting satellites - is limited by the accuracy of the atomic clock on each satellite. A series of calculations can get millimetre accuracy on the position of a stationary object, but for moving objects like cars and planes the accuracy is no better than a few metres. Only by making faster measurements can this accuracy be improved, something enabled by a more accurate definition of the second.
"That is why GPS is not yet good enough to land a passenger aircraft on its own," Prof Gill says.
Pretty cool stuff.
According to Silvanus Thompson in his famous (and awesome!)(c1910) calculus book the word second comes from the term "second minute".
I thought that was a neat and strange word origin (if correct).
to quote him...
"When they came to require still smaller subdivisions of time, they divided each minute into 60 still smaller parts, which, in Queen Elizabeth's days, they called "second minutes" (i.e. small quantities of the second order of minuteness). Nowadays we call these small quantities of the second order of smallness "seconds"."
But the real question is can MS make a download status bar that is 1000 times more precise and does not go from 2 minutes to 20, then to 4 minutes, then to 5 minutes etc. Or this invention does not affect a standard Microsoft Millisecond (which I believe is a random function?)
You can't handle the truth.
Unfortunately the world has not completely standardized on when and how these leaps seconds are to be inserted
Rubbish. This has been standardised for many years.
There is no place like ~!
Man that shit is complicated. No wonder we Americans never adopted the metric system. If I want to measure a yard, I don't need no fancy lasers. Just a yardstick!!
It's an awful point. When you build atomic clocks, you're not interested in measuring how long it takes the earth to go around the sun to great precision. You're not interested in actually keeping time for the next 30 billion years accurate to a second.
For that matter, if the talk I heard a year ago about the work at NIST on this very thing is still true, these atomic clocks can't maintain their accuracy for more than a week or so.
The "one second in 30 billion years" is a convenient extrapolation so that non-scientific persons get an idea of how accurate it is. It would be more correct to say that the atomic clock, in situations of normal operation, is accurate to one part in 10^18.
For that matter, it doesn't hold a wall-clock type value, like saying it's exactly 22:04:17.832... Our choice of reference for time (say, when "noon" is), is difficult to measure and quite arbitrary. Instead, you're interested in, say, how long a particular process takes (light making a round trip, or atomic decay), measured to a very high degree of accuracy (and precision).
Of course units of time are arbitrary. All units are arbitrary. Dimensions (length, time, etc.) and fundamental constants are non-arbitrary, but don't have any "natural" expression in terms of the units we use. (The most natural system of units is arguably expressing everything in terms of fundamental constants.) Seconds, minutes, hours, and years have arbitrary definitions for our convenience, just like any other unit.
Can anyone think of one good example where this clock serves any real purpose
Predicting earthquakes and volcanos.
Finding oil, gas, mineral deposits.
Hardly automatic, but attaining extreme accuracy cheaply can only help.
With a few high precision clocks broadcasting, it is possible to triangulate position precisely and hence the delay time. Precision in timing translates into precision in distance. If stuff is moving inches per decade or century, it would be interesting to know exactly how that movement is accomplished.