Louis Georges Gouy (19.02.1854-27.01.1926) was a French physicist and a member of the Paris Academy of Sciences (1913). He was born in Vals-les-Bains. He was professor at the University of Lyon.
His work was in the field of spectroscopy, thermodynamics, molecular physics (Brownian motion, osmotic pressure, electrocapillarity), acoustics, optics and mathematical physics. He studied the speed of light, the diffraction of light at an edge and the nature of white light. In 1888 he proved the thermal nature of Brownian motion, and in 1910 he developed the theory of the electrical double layer.