Alfred Potier (11 May 1840, in Paris – 8 May 1905, in Paris) was a French polymath who contributed to many theoretical and practical fields of science when this was rapidly expanding. His interests covered mainly mathematical physics, the nature of light and the ether, geology, electricity and magnetism and their practical applications in industry. His name’s claim to fame rests, however, on a little explored footnote inserted by Michelson and Morley in their famous paper “On the Relative Motion of the Earth and the Luminiferous Ether”.