Laser physicists in Munich have developed a method to record the change of states of electrons in atoms when they are struck by light. Those changes happen incredibly fast, in a period of time called, wonderfully, a "zeptosecond."
The specific study was done on helium atoms, which have two electrons. When a light with enough energy strikes a helium atom, the energy is absorbed in one of two ways -- either all of it by one of them, or half-and-half. Either way, one electron is ejected from the atom, and the new process, described in the story, can see that happen because of its "zeptosecond" shutter speed. The actual duration of a zeptosecond, if you are curious, is a trillionth of a billionth of a second -- slightly less than the attention span of the modern media.
One of the project directors described how the process could help verify quantum behavior previously only predicted by theory: "“We can now derive the complete wave mechanical description of the
entangled system of electron and ionized helium parent atom from our
He did not add, but we may assume it as understood, that we now have a good reason to use the word zeptosecond, which is almost justification enough.