Prosper-René_Blondlot

Prosper-René Blondlot (French: [pʁɔspɛʁ ʁəne blɔ̃dlo]; 3 July 1849 – 24 November 1930) was a French physicist, who in 1891 made the first measurement of the speed of radio waves, but is now mostly remembered for his "discovery" of N rays, a phenomenon that subsequently proved to be illusory.