Heaviside, Oliver (1850-1925)

English physicist. In 1902 he predicted the existence of an ionized layer of air in the upper atmosphere, which was known as the Kennelly-Heaviside layer but is now called the E-layer of the ionosphere. Deflection from it makes possible the transmission of radio signals around the world, which would otherwise be lost in outer space.

Heaviside was born in London. Because of severe hearing difficulties, he was mainly self-taught and was unemployed most of his life.

When Heaviside became involved with the passage of electricity along conductors, he modified Ohm's law to include inductance and this, together with other electrical properties, resulted in his derivation of the equation of telegraphy. On considering the problem of signal distortion in a telegraph cable, he came to the conclusion that this could be substantially reduced by the addition of small inductance coils throughout its length, and this method has since been used to great effect.

In Electromagnetic Theory (1893-1912), Heaviside extended Scottish physicist James Clerk Maxwell's discoveries as well as making many valuable discoveries of his own. In the third volume, he considered wireless telegraphy.