Hannes Olof Gösta Alfvén was a Swedish electrical engineer and plasma physicist who won the 1970 Nobel Prize in Physics for his research on magnetohydrodynamics (MHD). He discovered a type of MHD wave that is now called Alfvén waves. He first studied electrical power engineering and later worked in research and teaching related to plasma physics and electrical engineering. Alfvén contributed to many areas of plasma physics, including theories about the behavior of auroras, the Van Allen radiation belts, how magnetic storms affect Earth's magnetic field, Earth's magnetosphere, and the movement of plasmas in the Milky Way galaxy.

Education

Alfvén earned his doctorate from the University of Uppsala in 1934. The title of his thesis was "Studies on High-frequency Electromagnetic Waves."

Early years

In 1934, Alfvén taught physics at the University of Uppsala and the Nobel Institute for Physics, which later became the Manne Siegbahn Institute of Physics in Stockholm, Sweden. In 1940, he became a professor of electromagnetic theory and electrical measurements at the Royal Institute of Technology in Stockholm. In 1945, he held the position of Chair of Electronics, a title that changed to Chair of Plasma Physics in 1963. From 1954 to 1955, Alfvén worked as a Fulbright Scholar at the University of Maryland, College Park. In 1967, after leaving Sweden and spending time in the Soviet Union, he moved to the United States. Alfvén worked in the electrical engineering departments at the University of California, San Diego, and the University of Southern California.

Later years

In 1991, Alfvén retired from his position as a professor of electrical engineering at the University of California, San Diego and as a professor of plasma physics at the Royal Institute of Technology in Stockholm. During his later years, he spent time in both California and Sweden. He died at the age of 86.

Research

In 1937, Alfvén suggested that if plasma spread throughout the universe, it could carry electric currents that create a galactic magnetic field. After winning the Nobel Prize for his work in magnetohydrodynamics, he emphasized that:

His research on electric currents in the aurora (based on earlier work by Kristian Birkeland) was confirmed in 1967. These currents are now called Birkeland currents.

British scientist Sydney Chapman strongly disagreed with Alfvén. Many scientists believed Alfvén’s ideas were not mainstream. R. H. Stuewer noted that "…he remained an outsider, gaining little respect from other scientists even after receiving the Nobel Prize…" and often had to publish his work in less well-known journals. Alfvén recalled:

Alfvén played a key role in the development of:
• Plasma physics
• Charged particle beams
• Interplanetary medium
• Magnetospheric physics
• Magnetohydrodynamics
• Studies of solar phenomena (such as the solar wind)
• Aurorae science

In 1939, Alfvén proposed the theory of magnetic storms and auroras and the theory of plasma movement in Earth’s magnetosphere. This paper was rejected by the U.S. journal Terrestrial Magnetism and Atmospheric Electricity.

Applications of Alfvén’s research in space science include:
• Theory of the Van Allen radiation belts
• Changes in Earth’s magnetic field during magnetic storms
• The magnetosphere (a protective layer of plasma around Earth)
• Formation of comet tails
• Formation of the Solar System
• Behavior of plasmas in galaxies
• Physical cosmology

Alfvén’s ideas followed those of Kristian Birkeland, the founder of magnetospheric physics. At the end of the nineteenth century, Birkeland proposed (with strong evidence) that electric currents flowing along Earth’s magnetic fields into the atmosphere caused auroras and magnetic disturbances near the poles.

Areas of technology influenced by Alfvén’s work include:
• Particle accelerators
• Controlled thermonuclear fusion
• Hypersonic flight
• Rocket propulsion
• Slowing down spacecraft during reentry

Contributions to astrophysics:
• Galactic magnetic field (1937)
• Discovery of nonthermal synchrotron radiation from space objects (1950)

Alfvén waves (low-frequency waves in plasma) are named after him and move at the Alfvén speed. Many of his theories about the solar system were confirmed as late as the 1980s through observations of comets and planets. However, Alfvén noted that astrophysics textbooks rarely covered important plasma-related ideas:

Alfvén reported that in 17 widely used astrophysics textbooks, none mentioned the pinch effect, none discussed critical ionization velocity, only two mentioned electric circuits, and three mentioned double layers.

Alfvén believed the Big Bang theory had a problem because scientists tried to explain the universe’s origin using mathematical models instead of starting with observable evidence. He also thought the Big Bang was a myth used to explain the universe’s creation. Alfvén and others proposed the Alfvén–Klein model as an alternative to the Big Bang and steady-state theories.

Personal life

Hannes Alfvén was married to Kerstin from 1910 to 1992. Together, they had five children: one son and four daughters. Their son became a doctor, while one daughter became a writer and another became a lawyer in Sweden. The writer was Inger Alfvén, who is well known for her work in Sweden. Hugo Alfvén, a composer, was Hannes Alfvén's uncle.

Alfvén studied the history of science, Eastern philosophy, and religion. He did not follow a religion and was critical of religious beliefs. He spoke Swedish, English, German, French, and Russian, and also knew some Spanish and Chinese. He was worried about the challenges of safely managing radioactive waste for a long time.

Alfvén was interested in problems related to the universe and the study of auroras, or northern lights. He used a well-known book about auroras called Das Phänomen des Polarlichts by Wilfried Schröder. Letters written by Alfvén, Hans-Jürgen Treder, and Schröder were published to celebrate Treder's 70th birthday. Schröder wrote about the relationships between Treder, Alfvén, and himself in his publications.

Alfvén died on April 2, 1995, in Djursholm at the age of 86.

Awards and honours

The Hannes Alfvén Prize is given every year by the European Physical Society to recognize important work in plasma physics. This prize is named after Hannes Alfvén. The asteroid 1778 Alfvén is also named after him.

Hannes Alfvén was one of the few scientists who became a foreign member of both the United States and Soviet Academies of Sciences.