Krypton atom with its electrons' movement. Credit: courtesy Lawrence Berkeley National Laboratory.
Physorg.com reported on August 4 that for the first time in history, scientists have observed an atom's electrons moving in real time: "A classical diagram of a krypton atom (background) shows its 36 electrons arranged in shells. Researchers have measured oscillations of quantum states (foreground) in the outer orbitals of an ionized krypton atom, oscillations that drive electron motion." The German-American team at Berkeley used flashes of laser light to capture the movement of a krypton atom's electrons. How fast were these flashes?
The team ionized Krypton gas, and used incredibly short attosecond pulses of intense ultra-violet light ot capture fine details: "with far shorter pulses of extreme ultraviolet light on the 100-attosecond timescale (an attosecond is 10^-18 second, a quintillionth of a second), they were able to precisely measure the effects on the valence electrons."
Wiki defines attosecond as: "the time it takes for light to travel the length of three hydrogen atoms." And: "One attosecond is to one second what one second is to twice the age of the universe."
Full report here; the findings were also reported on August 5 in Nature.