Oliver HeavisideOliver Heaviside (May 18, 1850 - February 3, 1925) was a self-taught British physicist.
Although he was a good scholar, he left school at 16 and became a telegraph operator. However he continued to study and, in 1872, while working as a chief operator in Newcastle upon Tyne, he started to publish papers on electricity.
Between 1880 and 1887 he developed the operational calculus (involving the D notation for the differential operator, to which he is credited of creating), a method of solving differential equations by transforming them into ordinary algebraic equations which caused a great deal of controversy when first introduced, owing to the lack or rigour in his derivation of it.
He also developed the Heaviside step function.
In later years his behaviour became quite eccentric, having been at odds with the scientific establishment for most of his life. Most of his recognition he gained post mortem.