Hannes Alfvén
Hannes Alfvén | |
|---|---|
| Born | 30 May 1908 Norrköping, Sweden |
| Died | 2 April 1995 (aged 86) Djursholm, Sweden |
| Nationality | Swedish |
| Known for | Magnetohydrodynamics, Alfvén waves, the plasma universe |
| Awards | Nobel Prize in Physics (1970) |
| Scientific career | |
| Fields | Plasma physics, Astrophysics, Cosmology |
| Institutions | Royal Institute of Technology, Stockholm; University of California, San Diego |
Hannes Olof Gösta Alfvén (30 May 1908 – 2 April 1995) was a Swedish plasma physicist who founded magnetohydrodynamics and received the 1970 Nobel Prize in Physics "for fundamental work and discoveries in magnetohydrodynamics with fruitful applications in different parts of plasma physics." He is the single most important ancestor of the plasma-cosmology and Electric Universe material collected on this wiki.
Alfvén's core discovery, published in 1942, is that a magnetised conducting fluid can carry a transverse wave in which the magnetic field lines oscillate like plucked strings — the Alfvén wave, now a standard tool in solar, magnetospheric and fusion physics. He introduced the guiding-centre approximation for charged-particle motion, developed the theory of magnetic double layers, and was the first to argue that the aurora is driven by field-aligned electric currents flowing along the Earth's magnetic field — the currents predicted by Kristian Birkeland and now called Birkeland currents. Every one of these ideas was resisted for years and every one is now standard.
His major books are Cosmical Electrodynamics (1948; second edition with Carl-Gunne Fälthammar, 1963), Worlds–Antiworlds (1966) and Cosmic Plasma (1981).
The plasma universe
Alfvén's later position, and his quarrel with astrophysics, can be stated compactly. He held that the universe is overwhelmingly plasma; that plasma does not behave like a magnetised fluid at large scales but organises itself into filaments, sheets and double layers carrying electric currents; and that cosmology built on gravity and idealised magnetohydrodynamics alone therefore describes a universe that does not exist. He was blunt that his own frozen-in flux theorem had been over-applied, calling for it to be dropped where currents matter.
He argued for extrapolating from laboratory plasma to space rather than from mathematics to space, and coined the term plasma universe for the resulting picture: an evolving, filamentary, electrically active cosmos with no beginning in a singularity. With Oskar Klein he developed an alternative Alfvén–Klein cosmology in which matter and antimatter ("ambiplasma") separate and annihilate at boundary layers, driving expansion of a local region rather than of space itself. That specific model has not survived; the general programme has.
Mainstream astrophysics accepts Alfvén's plasma physics wholesale and rejects his cosmology. Alfvén's own view, stated repeatedly in his later years, was that cosmologists ignored plasma behaviour because they were mathematicians rather than experimenters — a charge he made in his Nobel lecture itself.
On this wiki
Alfvén stands behind most of Category:Plasma Cosmology and Category:Plasma.
- Anthony L Peratt, Alfvén's student and the chief technical continuer of the programme, is heavily represented: "Evolution of the Plasma Universe: I Double Radio Galaxies, Quasars, and Extragalactic Jets" (IEEE Transactions on Plasma Science, 1986), "The Evidence for Electrical Currents in Cosmic Plasma" (1990), the textbook "Physics of the Plasma Universe" (1992), and "Plasma Universe: Beyond the Big Bang" (2000). Peratt's particle-in-cell simulations of interacting Birkeland current filaments producing double radio galaxies are the strongest specific claim in this literature.
- Eric J Lerner extends the argument to the Big Bang directly, and Donald E Scott's "The Electric Sky: A Challenge to the Myths of Modern Astronomy" (2006) and Wallace Thornhill's work develop it into the Electric Universe position.
- David Talbott's "The Plasma Universe of Hannes Alfvén" (EdgeScience, 2011) is the wiki's biographical treatment, and dwells on how consistently Alfvén's papers were rejected by mainstream journals even after the Nobel.
- Bo Lehnert, a Swedish plasma physicist of Alfvén's own school, appears here on plasma and unified-field topics.
- The relevant topic pages are Plasma Cosmology, Electric Universe and The Electric Universe.
The honest boundary is worth marking. Alfvén was not an outsider; he was a Nobel laureate whose plasma physics is in every textbook. What is contested is the extension to cosmology — whether large-scale cosmic structure is current-driven, and whether redshift and the microwave background admit non-expansion readings. This wiki argues that it is; mainstream astrophysics holds that gravity and dark matter suffice.