Giuseppe Sansone

An electron in an atom is like a tennis player waiting for a serve. The light flash is the ball, moving at a speed the eye can't follow. The new device catches the moment the racket meets the ball with a precision previously unimagined. The setup uses two laser beams: one strikes the atom, the other acts as a stopwatch.

A high-speed camera capable of capturing the motion of electrons is an attosecond interferometer. It sends two laser pulses at a substance with a tiny delay. The first, ultraviolet, acts like a flash, knocking an electron out of the molecule. The second, infrared, like an invisible hand, gently nudges or slows this electron in flight.