Vitaly Ginzburg, a Nobel Prize-winning Russian physicist and one of the fathers of the Soviet hydrogen bomb, has died in Moscow. He was 93.

Ginzburg died late Sunday of cardiac arrest, the Russian Academy of Sciences said Monday.

Ginsburg won the 2003 Nobel Prize in physics with two other scientists for their contribution to theories on superconductivity, the ability of some materials to conduct electricity without resistance.

In the late 1940s and early 1950s, Ginzburg was a key member of the group working under Igor Tamm that developed the Soviet hydrogen bomb. Ginzburg wrote that he and Andrei Sakharov _ considered the father of the Soviet H-bomb _ formulated the two ideas that made it possible to build the thermonuclear device.

In a career that spanned seven decades, Ginzburg authored several groundbreaking studies in various fields _ such as quantum theory, astrophysics, radio-astronomy and diffusion of cosmic radiation in the Earth's atmosphere _ that were of "Nobel Prize caliber," said Gennady Mesyats, the director of the Lebedev Physics Institute in Moscow, where Ginzburg worked.

"I can hardly list all the fields of physics to which he contributed ," Mesyats said in televised comments Monday.

Russian President Dmitry Medvedev praised Ginzburg as a "top physicist of our time whose discoveries had a huge impact on the development of national and world science" in a letter of condolences released by the Kremlin.

Ginzburg was born into a Jewish family in 1916, a year before the Bolshevik Revolution, and grew up in times of economic degradation and hunger, according to his autobiography written for the Nobel Prize Committee.

His career began in the late 1930s, a time of Stalinist purges and pervasive anti-Semitism. Ginzburg was blacklisted and faced persecution, but "was saved by the hydrogen bomb," he wrote in the autobiography.

He became a member of the Soviet Academy of Sciences in 1953. He also was a longtime editor of a leading scientific magazine on theoretical physics and educated hundreds of disciples.

A vehement atheist, Ginzburg strongly opposed the growing role of the Russian Orthodox Church in state affairs after the 1991 Soviet collapse, protesting its attempts to have a say in political and secular matters and introduce religious lessons in schools. Continued...