Disorder and fluctuations in complex physical systems: Nobel Prize winner in physics 2021 Giorgio Parisi

In 2021, the Nobel Prize in Physics was awarded “for innovative contributions to our understanding of complex systems,” with half awarded jointly to Shukuro Manabe and Klaus Hasselmann “for the physical modelling of Earth’s climate, quantifying variability and reliably predicting global warming”, and the other half to Giorgio Parisi “for the discovery of the interplay of disorder and fluctuations in physical systems from atomic to planetary scales”. Parisi discovered hidden patterns in disordered, complex materials. His discoveries are one of the most important contributions to the theory of complex systems. He proved that equilibrium is never achieved in spin glasses, because frustrations do not allow all limitations to be satisfied. In reality, there are an infinite number of practically equilibrium states in which frustrations tend to a minimum. Parisi’s research interests cover 14 different directions.