> Today’s best atomic clocks are billions of times more accurate and precise than any other type of clock. If they had been running since the Big Bang, 13.8 billion years ago, they would have lost or gained less than a second.

Absolutely incredible, but then confused by the next assertion that is made without context:

> New kinds of clocks may soon open up capabilities that previous generations could only dream about.

What is possible by pushing past that incredibly narrow margin of 1s in 13b years? What dreamy capabilities do we get that we don’t enjoy today?

Edit: I’d assumed they were talking about new approaches to making these clocks more accurate, but I wonder if they’re referring to power and form factors? I.E. an atomic clock the size of a grain of rice: https://www.nist.gov/noac/success-story-chip-scale-atomic-cl...

Cost, size, weight, and power are definitely things that can be improved on. The atomic clocks you can buy for a lab are big 3U boxes but shrinking it down to something portable is the future.

I actually work with one of those chip scale atomic clocks. The goal is to put it in space. If you need precise timing in space, the current state is to lock to a GPS reference clock (just for timing, don't care about position), train an OCXO, and let it drift for a day or two before you require GPS again. OCXOs (and crystal oscillators in general) can be very accurate but the stability is easily affected by temperature swings. So as your satellite goes in and out of the sunlight or as components inside turn on and off, the surrounding temperature changes and can make the clock drift. This isn't a problem on earth since you can always have a GPS receiver running but on a power constrained satellite, this is not ideal. The CSAC gets 100x better thermal stability than even some of the best space-qualified OCXOs. This means you could potentially run for 100x longer before you need to reacquire GPS, assuming the same environment and performance requirements. The CSAC also has a brain inside so potentially you can do all of your characterization on the ground and not even need a GPS receiver onboard. It also requires much less time to become stable after powering on than a normal crystal oscillator.

You get the same benefits on the ground, super precise timing for the processors and modems without necessarily needing a GPS receiver. The modern assumption (and pretty much proven in Ukraine) is that GPS will be completely unavailable on a battlefield. Anything portable or battery-powered will likely not be able to make use of newer anti-jam features of GPS (very power hungry) so you need something small, precise, and quick to come online.

Modern waveforms often require very tight timing to properly demodulate so having a pocket sized atomic clock solves a lot of problems.

> What is possible by pushing past that incredibly narrow margin of 1s in 13b years? What dreamy capabilities do we get that we don’t enjoy today?

You can measure speed (via special relativity) and altitude (via gravity/general relativity) with atomic clocks [0], so with a more accurate clock, you should be able to calculate your speed/altitude more accurately.

GPS is already pretty good at measuring speed/altitude, but its not always very accurate, and it only works if you can receive the satellite's signal. In theory, a more accurate atomic clock would solve both of these problems (as long as you had an equally-accurate clock at a fixed location to compare to).

[0]: https://news.ycombinator.com/item?id=16473776

There are still big leaps, like their optical lattice clock that's sensitive to the gravitational difference caused by tidal effects on the earth's crust.

It can detect gravitational differences of a few cm!

Pretty sure you can rig something far better than radar if you have the ability to detect extremely tiny gravitational waves via an array of hyper-accurate clocks.

> What dreamy capabilities do we get that we don’t enjoy today?

The next gen will have an alarm with snooze button.

In radio astronomy, more precise clocks can directly improve the quality/resolution of observations.

> Data received at each antenna in the array include arrival times from a local atomic clock, such as a hydrogen maser. At a later time, the data are correlated with data from other antennas that recorded the same radio signal, to produce the resulting image. The resolution achievable using interferometry is proportional to the observing frequency.

https://en.wikipedia.org/wiki/Very-long-baseline_interferome...

What are these atomic clocks measured against?