Alfven is the acknowledged father of “plasma cosmology,” a new way of seeing formative processes in the heavens. Proponents of plasma cosmology suggest that vast but invisible electric currents play a fundamental role in organizing cosmic structure, from galaxies and galactic clusters down to stars and planets. The Big Bang hypothesis, black holes, dark matter, and dark energy are only a few of today’s popular cosmological themes disputed by scientists working with this new perspective.
Many central tenets of plasma cosmology emerged from laboratory experiments with plasma and electric discharge, and it was Alfvén himself who showed that plasma behavior in the laboratory can be scaled up to galactic dimensions: vast regions of plasma in space behave similary to plasma on earth.
Underscoring the enormity of ignoring cosmic electromagnetic effects in cosmology is the fact that the electric force between charged particles is some 39 orders of magnitude (a thousand trillion trillion trillion) times stronger than the gravitational force. In comparative terms, gravity is incomprehensibly weak; a hand-held magnet will raise a small metallic sphere against the entire gravity of the Earth.
Alfvén’s documentation of laboratory plasma experiments eventually made it impossible to ignore the role of electricity in space. He explained the auroras based on the work of his predecessor Kristian Birkeland; correctly described the Van Allen radiation belts; identified previously unrecognized electromagnetic attributes of Earth’s magnetosphere; explained the structure of comet tails; and much more.
Alfvén’s interest in magnetic fields laid the foundations of today’s magnetohydrodynamic theory, a theory widely employed by astrophysicists. In the original formulations of the theory, Alfvén spoke of magnetic fields being “frozen” into neutral plasma, and the magnetohydrodynamic equations he formulated implied that the electric currents that create magnetic fields could be effectively ignored. Hence, the plasma activity on the Sun and in more remote space could be analyzed without reference to any larger domain of electric currents or electric circuits.
To this notion astronomers were readily attracted, and for a time they thought they had an ally in the brilliant electrical engineer. Although his “fundamental work and discoveries in magnetohydrodynamics” led to his Nobel Prize in 1970.
Cellular Structure and Filamentation of Space
The fundamental truth discerned by Alfvén, but ignored by proponents of his “magnetohydrodynamic” model, is that plasma in space cannot have a magnetic field permanently “frozen” in to it. In space plasma environments, electric currents are required to create and sustain magnetic fields.
“In order to understand the phenomena in a certain plasma region, it is necessary to map not only the magnetic but also the electric field and the electric currents. Space is filled with a network of currents that transfer energy and momentum over large or very large distances. The currents often pinch to filamentary or surface currents. The latter are likely to give space, interstellar and intergalactic space included, a cellular structure.”
Plasma experiments show that strong electric fields can be present across the walls of these cellular sheaths (double layers), and the presence of the these fields is essential to understanding plasma behavior. To ignore this cellular structure in the cosmos, Alfvén observed, is to assume that deep space plasmas “have properties which are drastically different from what they are in our own neighborhood. This is obviously far more unpleasant than our inability to detect distant ‘cell walls.’
Hence, a thorough revision of our concept of the properties of interstellar (and intergalactic) space is an inevitable consequence of recent magnetospheric discoveries.”
Even before the space age, Alfvén had come to realize that, for stars, the electrical circuitry will show up in equatorial current sheets and polar current streams. Based on laboratory plasma experiments, Alfvén noted that electromagnetic energy could be stored in a star’s equatorial ring until a critical juncture when that energy switched to a polar discharge. The resulting jet would be energized by a particle-accelerating double layer:
the gravity of a star would then give way to the incomparably more powerful electric force, accelerating matter away from the star.
And now, thanks to more powerful telescopes, we see exactly what Alfvén envisioned. One noteworthy form is the Herbig Harro (HH) object; such objects are now counted in the hundreds and observed in sufficient detail to invalidate all early, non-electric theories of such formations.
X-Rays and Synchrotron Radiation
The intense electromagnetic activity across the cosmos requires a vast complex of electric fields and electrical circuitry, just as Alfvén confidently predicted decades before the new telescopes were launched into space. Prior to the launch of the X-ray telescope Uhuru in 1970, for example, astronomers knew of only two X-ray sources in the heavens—Scorpius X-1 and the Crab Nebula. But the Chandra and XMM-Newton X-ray telescopes, more recently launched into space, began to reveal X-ray activity in virtually every corner of the universe, even in the deepest vacuum between galaxies.
X-rays require an acceleration of charged particles up to speeds far beyond the capabilities of thermal expansion or gravitational acceleration. So it’s understandable that most astronomers did not anticipate an X-ray universe. Of course, we routinely employ electric fields today to produce X-rays, and if Hannes Alfvén had lived to see the recent results, he would have not been surprised at all.
Though the history and practice of science is often cluttered with dismissals of scientific “outsiders” and obstructive allegiance to dogma, it can at least be said that in the last 40 years astronomers have grudgingly come to accept an entirely different view of the universe from the one they started with. And for this, no one deserves more credit than the cosmic electrician, Hannes Alfvén.
Written by David Talbott