Freakishly accurate-to-an-atom-width mirrors are one big reason your modern GPU is so damned expensive. Story by Jeremy Laird • 2h. P rofiteering, the AI boom, ...

Many modern atomic clocks use oscillations of strontium atoms rather than cesium to measure time; the most precise of these is accurate to within 1/15,000,000,000 of a second.

But an AI weather model's predictions must be accurate for that to happen. Otherwise, the whole effort falls apart, and entire communities are put in harm's way.