Manfred Eigen, pioneer of study of exceptionally fast chemical reactions, dies aged 91

Manfred Eigen, who was awarded a one-half share of the 1967 chemistry Nobel prize for developing ways to study extremely fast chemical reactions, has died aged 91. Eigen developed techniques to determine the rates of reactions and processes previously thought to be unmeasurable as they take place in nanoseconds. He pioneered a process called relaxation, in which an energy pulse – often in the form of high-frequency sound – was used to set off a rapid reaction in a chemical system that had settled into equilibrium. The reaction could then be measured using spectrometry to determine the energy absorbed.