This is a bit sciency to include here, but it still astounds me: they’ve actually measured the time it takes an electron to transfer from one atom to another. 320 attoseconds, or 3.2 x 10^-16 seconds. Or 0.32 femtoseconds. I’m surprised, because it’s faster than processes which take place on the nuclear scale, which are about one femtosecond.
This measurement depends on the rate of hole decay, or the “natural lifetime” of the hole, which is known to take 500 attoseconds. I don’t know how they measure that–at some point there has to be an absolute measurement here. But it’s still astonishing. The glories of science!