Carlos Sanchez



Barry M. Wood, Carlos Sanchez, and Richard G. Green determined the value of Planck’s constant—the relationship between the frequency of a photon and its energy—to the lowest uncertainty ever attained, an achievement key to the SI redefinition by the International Bureau of Weights and Measures in 2019. This redefinition enabled a move away from the last artifact-based unit definition of kilogram to a new one based on fundamental constants. Their achievement paves the way for unprecedented methods of measurement that use quantum phenomena, opening new levels of accuracy and measurements at scales not possible before. They have changed the face of measurement and instrumentation for decades to come.

Sanchez is a research officer, retired, at the National Research Council (NRC) Canada, Metrology Research Centre, Ontario, Canada.