The science of taking measurements. We engineers do lots of it.

Metrology Equipment covers everything from a plastic rule to an electron microscope.

I'm sure DARPA is thinking of difficult projects just to justify themselves and their funding.

Were thwarted by the headlights of an oncoming car.

Why no bugsplat icon??

I'd be happy with a PC clock that is more accurate than the usual +/-3 minutes/day!!

Why ARE PC clocks still so bloody inaccurate?

Quartz crystals are good at doing about 1 to 40MHz. PC clocks go at 32KHz to reduce power and hence the cost of the backup battery. The frequency of quartz crystals varies with temperature, some more than others. You get what you pay for. The crystal circuit also includes the PCB, a few capacitors an a chip. Variations in these components add a small error to frequency. Many years ago, that was fixed by adding a small variable capacitor, but that costs some money to add, and more to set correctly.

If you want you PC to know the right time, use some network time protocol software.

http://en.wikipedia.org/wiki/Ntpd

Still looking for a clock that reads either: "Yes, there is time." or "No, there isn't."

The first thing to say is how misleading the hype is on size & accuracy of Chip-Scale Atomic Clocks. The players in this field always photograph the unpackaged devices because they look small. But to thermally stabilize them, the vacuum packaging they require is pretty large. Second, there are tricks with thermally stabilized multi-mode quartz oscillators & contactless packaging that get you "atomic clock" accuracy in that technology for a fraction of the cost, power consumption & size.

It's easy to laugh at the boffins of DARPA but have you ever wondered at the sometimes irrational things the British government do? Roswell controlled cyborgs the lot of them! Brings a new meaning to having had ones' chips.

DARPA is looking for a primary frequency standard in a 5cc volume, so yea, they are looking for an atomic clock. Unless you can calculate from first principles the vibration frequency of a hunk of quartz.

"DARPA is looking for a primary frequency standard in a 5cc volume"

Imagines the size of moth needed to discreetly hide such a device...

Holy $^&^%*(!