One second per millennium accuracy, it says. I wonder how much empirical testing has been done to compare these to traditional quartz watches. A quick Google se

One second per millennium accuracy, it says. I wonder how much empirical testing has been done to compare these to traditional quartz watches. A quick Google search puts quartz watches at about 15 seconds per month. I’m sure the atomic oscillator itself is more resistant to everyday variance (like temperature) than quartz, but I wonder if the detector is actually that much more accurate in practice, or if they’re just citing a theoretical number. Oh well, at the end of the day your clock is still going to vary based on your altitude (distance from Earth’s gravitational field), unless you also correct for that. ;)