British physicist Owen Willans Richardson made advancements in the scientific understanding of emission of electrons from hot surfaces, and coined the term thermionics for this work. In nineteen zero one he presented Richardson's law, which mathematically describes the relation between increases in the temperature of a hot surface and the amount of electric current released. In a Nineteen Eleven study he proved that electrons are emitted from metal as it is heated, not from the surrounding air, as had previously been assumed. In Nineteenn twenty eight he won the Nobel Prize for Physics. His work was vital in the development of vacuum or electron tubes used in twenty th century electronic devices.