Manfred Eigen, member of this Academy since 1981, passed away on 6 February 2019 in Göttingen (Germany) at the age of 91 years. Without doubt, the community lost with him one of the most important scientists of the last decades, whose broad activities covered the fields of chemistry, physics, and biology.
The measurement of the velocity of the reaction between two species in a solution is usually limited by their rate of mixing. Processes taking place on even shorter timescales were called immeasurably fast, until Eigen invented the relaxation techniques which permitted, in fact, the determination of the rates of the fastest reactions. For this development he was honoured in 1967 at the age of forty with the Nobel Prize of Chemistry.
He then directed his main interest to biological evolution. Starting with the problem of molecular self-organisation in living systems he became the founder of evolutionary biotechnology. His attempts to unify the approaches by chemistry, physics and biology led to the foundation of the Max Planck Institute for Biophysical Chemistry in Göttingen, which is now at the forefront of research and has then to become the home of further Nobel Prize Winners. He became honoured by numerous awards and distinctions.