Comment Re:Microhertz (Score 1) 328
This. Time and frequency are the quantities that current human tech can measure with the most precision.
You can generally get 11 or 12 digits of precision with student-grade equipment like counters and frequency analyzers, and consumer-grade electronics routinely use even greater precision.
For example, a GPS receiver uses about 50ns precision on a calendar that spans at least 100 years. That's 3.1536e9 seconds... at 5.0e-8 seconds precision... which means that GPS time is measured at over 16 digits of precision, with comparable accuracy. The precision is even greater if you allow for the understood digits for century, millennium, etc.
Yes, atomic scale features can be measured down to a few picometers. But we cannot measure the size of a macro scale object (say, a mountain or skyscraper) to the nearest picometer, which is essentially what we can do with time and frequency.