English physicist and electrical engineer who helped develop telegraphic and telephonic communications; in 1902 (independent of A. E. Kennelly) he suggested the existence of an atmospheric layer that reflects radio waves back to earth (1850-1925) WordNet 3.0 & Open English WordNet

Oliver Heaviside FRS was an English self-taught mathematician and physicist who invented a new technique for solving differential equations, independently developed vector calculus, and rewrote Maxwell's equations in the form commonly used today. Wikipedia

Electrical engineer, mathematician and physicist Wikidata