Stjepan Mohorovičić

Stjepan Mohorovičić (August 20, 1890 – February 13, 1980) was a Croatian physicist, geophysicist and meteorologist, known as the "father of positronium", whose existence he predicted in 1934.

Biography

Mohorovičić was born in the town of Bakar. Because of his longtime opposition and criticisms of theory of relativity he remained a high school professor his whole life. His work went largely ignored, especially in Croatia. He died in Zagreb. In 1916 he published an idea of the existence of smaller discontinuities in Earth's crust and mantle. He put forward his own theory about the composition and the formation of the Moon, explosive formation of lunar craters and predicted the existence of Moho layer on the Moon. The existence of Moho layer on the Moon was confirmed in 1969 by seismic measurements done by Apollo 11 crew.

His most significant work being the 1934 prediction of the existence of positronium, Mohorovičić is often called "the father of positronium". The electron-positron atom was experimentally discovered only in 1951 by Martin Deutsch. Positronium is the bound state of an electron and a positron and therefore the lightest atom. At the time, Mohorovičić did not identify the positron with Dirac's antielectron.