from the time-travels-in-divers-paces-with-divers-persons dept.
Researchers from Adelaide University worked with the National Institute of Standards and Technology (NIST) in the United States and the National Physical Laboratory (NPL) in the United Kingdom to review the future of the next generation of timekeeping.
They found that development is happening at such a fast rate that optical atomic clocks are well positioned to become the gold standard for timekeeping within the next few years, provided some technical challenges can be addressed.
"Optical atomic clocks have advanced rapidly over the past decade, to the point where they are now one of the most precise measurement tools ever built. They're more accurate than the best microwave atomic clocks and can even work outside the lab – this is a place that conventional atomic clocks have trouble venturing," said co-author Professor Andre Luiten from Adelaide University's Institute for Photonics and Advanced Sensing.
Optical atomic clocks are made from laser-cooled trapped ions and atoms. When scientists repeatedly probe the atoms with a laser, they respond only at a special frequency which can be converted into ticks to track time accurately.
The review into the next generation technology, which has been published in the journal Optica, outlines the key features, progress that's been made over the past decade, challenges and future applications.
"A decade ago, optical atomic clocks had no impact on the steering of international time. Today, at least ten have been approved for use," said Professor Luiten.
A roadmap for redefining how the second is measured is underway, but researchers have noted other potential uses for optical atomic clocks, including as gravity sensors that can aid in creating an international height reference system that's not based on sea level. Their precision and sensitivity also positions them as a useful tool for testing fundamental physics such as dark matter.
They could be relied on to maintain accurate time during satellite outages caused by solar storms or malicious attacks. This latter opportunity is seeing an outpouring of commercial interest in optical clocks, including from Adelaide University spin-out, QuantX Labs.
Despite the rapid development of this technology, the review does identify several key challenges. These include limitations to the operational capability of optical atomic clocks, with many still operating intermittently. Decisions around how to redefine the second also need to be made, including if a single type of optical atomic clock or a group are the most reliable way to replace caesium fountain clocks, with direct comparisons needed.
Supply chains for critical components are also underdeveloped, resulting in higher costs, however, researchers believe progress in quantum computing and bioscience are likely to lead to more affordable and accessible systems in the future.
Journal Reference: https://doi.org/10.1364/OPTICA.575770
(Score: 1, Redundant) by Username on Monday February 09, @06:14PM (2 children)
Why not redo time and have one day equal 100 kiloseconds?
(Score: -1, Redundant) by Anonymous Coward on Monday February 09, @06:48PM
Here's one reason why not: https://xkcd.com/927/ [xkcd.com]
(Score: 3, Informative) by VLM on Monday February 09, @08:31PM
Octal would be more fun
https://octarule.com/apps/octal-clock [octarule.com]
If the primary purpose of a unit is to easily break it into fractions, division by 60 isn't that bad, 8 is also pretty cool. Division by 10 isn't as bad as a prime number but its not as good as the alternatives.
(Score: 4, Interesting) by VLM on Monday February 09, @08:25PM (2 children)
Not really, see the 1960 time dilation experiment and more recently the Youtube channel Curious Marc trying to reproduce that experiment with period correct equipment. The factor of 100x improvement is interesting. The experiment runs up to the limits of 1960s technology. Given maybe 100000x better tech maybe we'd be using clocks directly as part of accelerometer IMU platforms to detect movement using time (I have not run the numbers). I suppose if 1960s cesium clocks can detect a jetliner flying intercontinental routes, 100x better might be militarily useful for a nuclear submarine to navigate under the ocean by measuring some time dilation effect.
I'd also propose the article misses the impact of GPS disciplined oscillators. If you're above the surface of the ocean and can run the radios for "a couple hours" you can get a GPSDO to work almost as well as a cesium clock. After all stratum 2 isn't that much worse than stratum 1 clocks in orbit...
So its a rather narrow use case... power up faster than a could hours and/or below the surface of the ocean and/or in a militarily jammed area.
figure 3 of the article is kind of funny thats pretty much the microwave cesium diagram but optical instead of microwave radio. The thorium clock design later in the article is wild.
The designs are still "big physics packages" it would be interesting to build a clock that uses high purity silicon. 29Si has an EPR resonance although I don't think it would be useful for clocks. Anyway being able to build an atomic clock on a silicon wafer would be pretty cool even as just a hard sci fi idea. Imagine if even cheap wristwatches could have atomic-grade clocks in them, assuming power consumption would be low enough.
(Score: 2) by Bentonite on Tuesday February 10, @02:29AM
It'll probably use less power to make a watch that uses a decent quartz clock (most digital watches have a pretty lousy clock that gains or loses a second a day) and re-synchronizes to GPS time daily (how there are restrictions on GPS and wireless technology, means there isn't really any low power GPS chipsets available without restrictions).
(Score: 2, Interesting) by Anonymous Coward on Tuesday February 10, @02:46AM
Cesium is orders of magnitude less stable than the clocks they're talking about here. And they are fussy devices outside the lab. Good enough for the measurements you're talking about, but not stable at all for keeping official time. GPS and other GPS-like satellites have moved on to rubidium, but they need to be tweaked and coddled and coerced to align to the official time, that is currently kept by an ensemble of clocks spread around the globe. It is no easy feat to synchronize these things over large distances where they are sitting in different heights in the gravity well. These things are getting to the level where you can notice general relativistic effects due to differences in heights of handfuls of meters. TFA is talking about how these new generation atomic clocks are now stable enough to be considered for official timekeeping jobs, but they apparently are also stable enough to operate well outside the controlled laboratory environment.
Clock comparisons and time transfer is hard [nasa.gov].
(Score: 5, Interesting) by atwork on Tuesday February 10, @04:37AM (1 child)
Please can we stop storing timestamps in local time or UTC or anything with a timezone. Let's use TAI [wikipedia.org] for all timestamps. Then things cannot finish before they start such as when daylight savings ends. And millisecond duration events cannot take thousands of times longer because a leap second has been added.
You can display your TAI timestamps in local times or UTC offsets or whatever you want. Just don't store them or do calculations based on those formats.
(Score: 0) by Anonymous Coward on Wednesday February 11, @04:18AM
This would work if only NTP, Linux, PostgreSQL, etc supported TAI.