Stjepan Mohorovicic
Encyclopedia
Stjepan Mohorovičić was a Croatia
n scientist
(physicists and geophysicist) born in the town of Bakar
and died in the city of Zagreb
, Croatia
. His father is the world-famous geophysicist Andrija Mohorovičić
.
Stjepan Mohorovičić is often called "the father of positronium
" because his most significant work is the prediction of the existence of positronium. Positronium is the bound state
of an electron
and a positron
(anti-electron) and therefore the lightest atom
. Mohorovičić's prediction of positronium was published in 1934 in the prominent German
scientific journal Astronomische Nachrichten
, where it was called "electrum". It was experimentally discovered by Martin Deutsch
in 1951 and became known as positronium.
Croatia
Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...
n scientist
Scientist
A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...
(physicists and geophysicist) born in the town of Bakar
Bakar
Bakar ) is a town in the Primorje-Gorski Kotar County in western Croatia. The population of the town is 1,566 , while the population of the municipality is 7,773. 90% declare themselves Croats . The old part of Bakar is situated on a hill overlooking the Bay of Bakar...
and died in the city of Zagreb
Zagreb
Zagreb is the capital and the largest city of the Republic of Croatia. It is in the northwest of the country, along the Sava river, at the southern slopes of the Medvednica mountain. Zagreb lies at an elevation of approximately above sea level. According to the last official census, Zagreb's city...
, Croatia
Croatia
Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...
. His father is the world-famous geophysicist Andrija Mohorovičić
Andrija Mohorovicic
Andrija Mohorovičić was a Croatian meteorologist and seismologist. He is best known for the eponymous Mohorovičić discontinuity and is considered a founder of modern seismology.-Early years:...
.
Stjepan Mohorovičić is often called "the father of positronium
Positronium
Positronium is a system consisting of an electron and its anti-particle, a positron, bound together into an "exotic atom". Being unstable, the two particles annihilate each other to produce two gamma ray photons after an average lifetime of 125 ps or three gamma ray photons after 142 ns in...
" because his most significant work is the prediction of the existence of positronium. Positronium is the bound state
Bound state
In physics, a bound state describes a system where a particle is subject to a potential such that the particle has a tendency to remain localised in one or more regions of space...
of an electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
and a positron
Positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...
(anti-electron) and therefore the lightest atom
Atom
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...
. Mohorovičić's prediction of positronium was published in 1934 in the prominent German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
scientific journal Astronomische Nachrichten
Astronomische Nachrichten
Astronomische Nachrichten , one of the first international journals in the field of astronomy, was founded in 1821 by the German astronomer Heinrich Christian Schumacher. It claims to be the oldest astronomical journal in the world that is still being published...
, where it was called "electrum". It was experimentally discovered by Martin Deutsch
Martin Deutsch
Martin Deutsch was an Austrian-American physicist, who was emeritus professor of physics at MIT. He is best known for being the discoverer of positronium.-Early life:...
in 1951 and became known as positronium.