In the blink of an eye, more attoseconds have expired than the age of Earth measured in – minutes. A lot more. To be precise, an attosecond is one billionth of a billionth of a second. The attosecond timescale is where you must go to study the electron action that is the starting point of all of chemistry. Not surprisingly, chemists are most eager to explore it with X-rays, the region of the electromagnetic spectrum that can probe the core electrons of atoms, the electrons that uniquely identify atomic species.