- Person
- Vitaly Ginzburg
- Lived
- 1916–2009
- Field
- Theoretical physics
- From
- Russian
The story
Cosmic rays are particles, mostly protons and atomic nuclei, that strike Earth from space with enormous energies. In the decades after their discovery, scientists debated where they came from. Supernovae had been proposed as a source in 1934, and in 1951 the Crab Nebula was identified as one, but there was no worked-out theory of how cosmic rays are produced, how they travel and how they could be traced to their origins.
Vitaly Ginzburg came to the problem through radio physics. During and after the Second World War he studied how radio waves travel through the ionosphere and other plasmas, and in 1946 he proposed that the solar corona should emit radio waves in the metre band, an early link between his work and the new science of radio astronomy. At Gorky University, where he taught from 1945, he trained postgraduates in physics with an astrophysical slant, and he later described himself, modestly, as an amateur astrophysicist.
A central idea in his work was that cosmic rays reveal themselves far from Earth. High-energy electrons spiralling in cosmic magnetic fields give off synchrotron radiation, so radio telescopes can map cosmic rays in distant parts of the galaxy and beyond. With his colleague S. I. Syrovatskii he set out the whole subject in The Origin of Cosmic Rays, published in 1964. The book moved from measurements of cosmic rays near Earth to the radio emission they produce, their energy losses and acceleration as they travel through interstellar space, and competing theories of their origin. It ended with a quantitative galactic model that predicted their composition, energy spectrum and gamma-ray and X-ray emission.
His astrophysical work won wide recognition. The Royal Astronomical Society awarded Ginzburg its Gold Medal in 1991, and the Cosmic Ray Commission of the International Union of Pure and Applied Physics gave him its Ó Ceallaigh Medal for contributions to cosmic-ray physics. The subject also ran in his family: his son-in-law, Lev Dorman, became a specialist in cosmic rays.
The origin of the highest-energy cosmic rays stayed on Ginzburg's list of key unsolved problems for the twenty-first century, and it is still pursued today by giant observatories.
Why it matters
Ginzburg's work helped turn cosmic rays into a branch of astrophysics, linking them to radio astronomy and to the violent processes, such as exploding stars, that shape our galaxy.
About Vitaly Ginzburg
Soviet-Jewish physicist whose Ginzburg–Landau theory of superconductivity won the 2003 Nobel Prize, and who survived Stalin’s antisemitic purges to become a fearless public voice.
More about Vitaly Ginzburg
- Vitaly Ginzburg founded a department to train physicistsIn 1968 Vitaly Ginzburg founded the Department of Problems of Physics and Astrophysics at the Moscow Institute of Physics and Technology, which he headed for decades.
- Vitaly Ginzburg helped bring genetics back to the USSRVitaly Ginzburg was among the scientists who helped end the dominance of Trofim Lysenko, the politically connected opponent of genetics, allowing modern genetic science to return to the Soviet Union.
- Vitaly Ginzburg co-created the theory of superconductorsIn 1950 Vitaly Ginzburg and Lev Landau published the Ginzburg–Landau theory of superconductivity, which became fundamental to all later work on superconductors and won Ginzburg the 2003 Nobel Prize.
- Vitaly Ginzburg kept a famous list of physics' big questionsFor three decades Vitaly Ginzburg compiled and updated a list of the most important unsolved problems in physics, publishing 30 problems for the 21st century in 1999.
- Vitaly Ginzburg explained how radio waves cross the skyDuring the Second World War and after, Vitaly Ginzburg developed the theory of how electromagnetic waves travel through plasmas such as the ionosphere, vital for long-distance radio.
- Vitaly Ginzburg's theory underpins MRI magnetsSuperconducting magnets in hospital MRI scanners and particle accelerators rely on type-II superconductors, whose behaviour is described by the theory Vitaly Ginzburg helped create.
- Vitaly Ginzburg ran a physics seminar for 1,700 sessionsFrom the mid-1950s Vitaly Ginzburg ran a weekly Wednesday physics seminar in Moscow that drew scientists from across the city and beyond, closing it at its 1,700th session in November 2001.
Sources
- Vitaly Ginzburg Wikipedia
- The Origin of Cosmic Rays (Ginzburg and Syrovatskii) Elsevier
- Vitaly Lazarevich Ginzburg (obituary) Physics Today
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.