Ahmed Zewail receives the 1999 Nobel Prize in Chemistry for being the first to reveal the decisive moments of a chemical reaction – the moments when chemical bonds are broken and formed.
     Zewail’s technique uses what can be thought of as the world’s fastest camera. The “shutter speed” of such a camera must be extremely high since molecules are very small (about 10^-9m) and move extremely rapidly (1 000 m/s). To obtain a sharp “image” of the molecules in the course of a chemical reaction requires a femtosecond (10^-15s) shutter speed.