Affiliation at the time of the award: California Institute of Technology (Caltech), Pasadena, CA, USA Prize motivation: "for his studies of the transition states of chemical reactions using femtosecond spectroscopy" Ahmed Zewail was born in Damanhur, Egypt, and grew up in Alexandria.

After some time spent working at the University of California, Berkeley, Zewail transferred to the California Institute of Technology in Pasadena in 1976, where he continues to work.

Chemical reactions in which molecules held together by atoms meet and reorganize into new compounds are one of nature's most fundamental processes.

In the late 1980s Ahmed Zewail developed methods for studying chemical reactions in detail.

By using laser technology to produce flashes of light just a few femtoseconds long, reactions can be mapped.