Electron diffraction photographs, 1925.
© Science Museum / Science & Society Picture Library
G P Thomson observed diffraction of electrons pasing through thin gold foil, recorded on photographic plates as concentric rings of varying intensity about the incident beam. This supported the idea of de Brogle that particles had wave-like properties. In 1937, Thomson received the Nobel Prize for this work, jointly with the American physicist C J Davison (1881-1958) who also observed electron diffraction using nickel crystals.