The prize is awarded whenever the academy recognizes a significant achievement in either of the two fields. Awardees receive a gold-and-silver medal. Previous prizewinners include Thomas Alva Edison, for his investigations in electric lighting ; Enrico Fermi, for his studies of radiation theory and nuclear energy ; and Charles H. Townes, for his development of the laser. One man, Samuel Pierpont Langley, has won both the Rumford Prize and the related Rumford Medal (the European equivalent of the Rumford Prize), both in 1886. The most recent award was given in 2021 to Charles L. Bennett for his contributions to cosmology. The prize has been given to researchers outside of the United States only twice—once to John Stanley Plaskett, from British Columbia, and once to a group of Canadian scientists "for their work in the field of long-baseline interferometry."