Hannes Alfvén facts for kids

Quick facts for kids Hannes Alfvén
Born	Hannes Olof Gösta Alfvén (1908-05-30)30 May 1908 Norrköping, Sweden
Died	2 April 1995(1995-04-02) (aged 86) Djursholm, Sweden
Alma mater	University of Uppsala
Known for	Magnetohydrodynamics Plasma cosmology Alfvén wave
Awards	Björkénska priset (1946) Nobel Prize in Physics (1970) Lomonosov Gold Medal (1971) Dirac Medal (1979) ForMemRS (1980) William Bowie Medal (1988)
Scientific career
Fields	Electrical engineering and Plasma physics
Institutions	University of Uppsala Royal Institute of Technology University of California, San Diego University of Maryland, College Park University of Southern California
Doctoral advisor	Manne Siegbahn Carl Wilhelm Oseen
Doctoral students	Carl-Gunne Fälthammar

Hannes Olof Gösta Alfvén (born May 30, 1908 – died April 2, 1995) was a brilliant Swedish scientist. He was an electrical engineer and a plasma physicist. In 1970, he won the Nobel Prize in Physics. He received this award for his important work on magnetohydrodynamics (MHD). This field studies how electrically charged gases, called plasma, move in magnetic fields.

Alfvén also discovered special waves, now called Alfvén waves. He started his career studying electrical power. Later, he focused on plasma physics and electrical engineering. He made many important discoveries about plasma. These include how auroras behave and the Van Allen radiation belts. He also studied how magnetic storms affect Earth's magnetic field. His work helped us understand the magnetosphere and plasma in the Milky Way galaxy.

Becoming a Scientist

Hannes Alfvén earned his PhD in 1934 from the University of Uppsala. His main research for his degree was about "Investigations of High-frequency Electromagnetic Waves."

Early Career and Teaching

In 1934, Alfvén started teaching physics at the University of Uppsala. He also taught at the Nobel Institute for Physics in Stockholm, Sweden. This institute was later renamed the Manne Siegbahn Institute of Physics.

In 1940, he became a professor at the Royal Institute of Technology in Stockholm. He taught about electromagnetic theory and electrical measurements. By 1945, he became the Chair of Electronics. His title changed to Chair of Plasma Physics in 1963.

Alfvén also spent time in the United States. From 1954 to 1955, he was a Fulbright Scholar at the University of Maryland, College Park. In 1967, he moved to the United States after living in Sweden and visiting the Soviet Union. He worked in the electrical engineering departments at the University of California, San Diego and the University of Southern California.

Later Life and Retirement

In 1991, Alfvén retired from his teaching positions. He was a professor of electrical engineering at the University of California, San Diego. He was also a professor of plasma physics at the Royal Institute of Technology in Stockholm.

Alfvén spent his later years living part-time in California and part-time in Sweden. He passed away at the age of 86.

Discoveries and Research

In 1937, Hannes Alfvén suggested an exciting idea. He thought that if plasma filled the universe, it could carry electric currents. These currents could create a magnetic field for entire galaxies.

After winning the Nobel Prize, he explained his ideas further. He said that to understand plasma, we need to map its electric fields and currents. He believed space is full of currents that move energy and momentum. These currents often form thin filaments or surfaces. He thought this might give space a "cellular structure."

His ideas about electric currents in the aurora were confirmed in 1967. These currents are now known as Birkeland currents.

Challenges and Recognition

Alfvén's work was not always easily accepted. Another leading space scientist, Sydney Chapman, often disagreed with him. Alfvén found it hard to get his papers published in major scientific journals. Many of his ideas were seen as "unorthodox." He sometimes had to publish his work in less known journals.

He once submitted a paper about magnetic storms and auroras. It was rejected because it didn't fit with the common physics theories at the time. Alfvén felt that referees often didn't understand his new ideas.

Despite these challenges, Alfvén played a key role in developing many fields:

• Plasma physics
• Charged particle beams
• Interplanetary medium (the space between planets)
• Magnetospheric physics (study of Earth's magnetic bubble)
• Magnetohydrodynamics
• Studying solar phenomena like the solar wind
• Aurorae science

In 1939, he proposed his theories on magnetic storms and auroras. This was the same paper that was rejected by the U.S. journal.

Space Science Applications

Alfvén's research helped explain many things in space science:

• The theory of Van Allen radiation belts.
• How Earth's magnetic field weakens during magnetic storms.
• The magnetosphere, which is like a protective plasma shield around Earth.
• How comet tails form.
• How the solar system formed.
• The movement of plasmas in our galaxy.
• Physical cosmology (the study of the universe's origin and evolution).

His ideas often built on the work of Kristian Birkeland. Birkeland had suggested that electric currents flowing into Earth's atmosphere caused auroras.

Technology and Astrophysics

Alfvén's contributions also helped improve various technologies:

• Particle accelerators
• Controlled thermonuclear fusion (trying to create energy like the sun)
• Hypersonic flight
• Rocket propulsion
• Reentry braking for space vehicles

In astrophysics, he made important contributions:

• He proposed the idea of a galactic magnetic field in 1937.
• He identified synchrotron radiation from astronomical sources in 1950. This is a type of light from fast-moving electrons in magnetic fields.

The Alfvén waves, which are low-frequency plasma oscillations, are named after him. Many of his theories about the solar system were proven true in the 1980s. This happened through measurements from comets and planetary magnetospheres.

Alfvén also pointed out that many astrophysics textbooks didn't explain known plasma phenomena well. He found that most textbooks didn't mention important concepts like double layers or the pinch effect.

Views on the Universe

Alfvén had different ideas about the Big Bang theory. He believed that scientists should start with observable phenomena. He felt that trying to explain the universe's origin only from mathematical theories was not the best approach. He even called the Big Bang a "myth" for explaining creation.

Alfvén and his colleagues proposed an alternative theory called the Alfvén–Klein model. This was a different way to understand the universe, compared to the Big Bang and steady state theory.

Personal Life

Hannes Alfvén was known for his good sense of humor. He cared deeply about social issues and worked for worldwide disarmament. He was also a bit wary of computers.

He enjoyed studying the history of science, oriental philosophy, and religion. He was irreligious and often questioned religious ideas. He could speak many languages, including Swedish, English, German, French, and Russian. He also knew some Spanish and Chinese.

Alfvén was very concerned about how to safely store radioactive waste for a long time. He was also interested in cosmology and all aspects of auroral physics.

Alfvén was married to his wife Kerstin (1910–1992) for 67 years. They had five children: one boy and four girls. Their son became a doctor. One daughter became a writer, and another became a lawyer in Sweden. His daughter, Inger Alfvén, is a well-known writer in Sweden. The famous composer Hugo Alfvén was Hannes Alfvén's uncle.

Awards and Honours

Many honors and awards recognize Hannes Alfvén's important work. The Hannes Alfvén Prize is given every year by the European Physical Society. It celebrates outstanding contributions in plasma physics. The asteroid 1778 Alfvén is also named after him.

Awards

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

Images for kids

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  Hannes Alfvén as a young man.

See also

In Spanish: Hannes Alfvén para niños