Davisson, Clinton Joseph (1881-1958), was an American physicist. He and Lester H. Germer discovered electron diffraction. He found that when electrons are directed at a piece of metal, they are reflected only in certain directions by the layers of atoms inside the metal. For his work, Davisson shared the 1937 Nobel Prize in physics with George P. Thomson of Britain. Thomson made a similar discovery by directing an electron beam at a paper-thin sheet of metal.