Jim Baen's Universe

NonFiction articles

Cosmic Electricity

Written by James P. Hogan

There's a story about a physics student who was asked in an exam question how he would use a barometer to determine the height of a tall building. Instead of the expected answer—measure the air pressure at the top and bottom, and calculate the altitude difference from the readings—he suggested lowering the barometer from the roof on a length of string and measuring the string. Alternatively, he said, you could make a pendulum and time the periods at the top and the bottom of the building; or you could measure the length of the barometer, stand it on end and, and work out the ratio of their shadows; or you could walk down the stairs, marking off "barometer lengths" on the wall as you went, and then add them up; but the simplest way might be to offer to give the barometer to the building superintendent if he'd tell you the height of the building. The story is often attributed to Neils Bohr, but others say that's an urban legend.

Mental flexibility is sometimes called "thinking sideways"; being able to see meanings other than the obvious. It's the kind of thing that solvers of cryptic crossword are good at. I got introduced to them at lunch breaks in an electronics lab that I once worked in. The clues don't always mean what you think they do.

The speck of cool, electrically neutral matter that we live on is very atypical. Over 99% of the observed universe exists as plasma, which contains separated charges that respond to electric and electromagnetic forces. The electric force between two charged particles is 39 orders of magnitude greater than their gravitational attraction. I've been working with numbers all my life, but I was stunned when I took a moment to work out just how huge a difference that is. It's a millionth of a millimeter compared to 10,000 times the estimated size of the universe.

Even in a plasma comprising just one charged particle in 10,000, which would be typical of the clouds that stars form from . . .

electromagnetic forces will dominate gravity by a factor of 10 million to one.

Yet modern astronomy remains essentially rooted in the work of such figures as Kepler, Newton, and Laplace, whose laws describe a mechanical universe consisting of electrically neutral bodies moving in a vacuum under the influence of gravity. And the reigning cosmological model, based on general relativity, is essentially a theory of gravity. If the Sun were reduced to the size of a speck of dust, the nearest star would be about four miles away. The weakest force known, operating on matter dispersed this diffusely, is said to be the main factor responsible for shaping the universe.

An alternative cosmology that recognizes the importance of electrical principles has been developed that traces back to the early years of the last century. Its proponents claim it to be simpler, more powerful predictively, and modeled by phenomena that are well understood and can be demonstrated in any laboratory. It requires none of the speculative, ad hoc explanations that the mainstream has had to resort to repeatedly when new observations failed to match expectations—or were never anticipated at all. I think it could be telling us some important things, and should be given more serious consideration than is the case at the present time.

Kristian Birkeland, 1867-1917

Around the beginning of the 19th century, the Norwegian Kristian Birkeland devoted a lot of field and laboratory work to studying the northern auroras. He concluded that they were caused by charged particles from the Sun, guided to the polar regions by the Earth's magnetic field. This was not well received by the theoreticians of his day, whose elegant, spherically symmetrical mathematical models treated the Earth as an isolated object in space.

In the 1960s and 70s, satellite measurements revealed the complex environment of fields, currents, and particles surrounding the Earth and forming part of a circuit connecting it with the Sun, and proved Birkeland to have been correct.

Birkeland's work was further developed and applied to cosmic rays by the Swedish physicist Hannes Alfvén, who started out as an electrical power engineer, became a professor of electronics and plasma physics . . .

Hannes Alfvén, 1908-1995

and in 1970 received the Nobel Prize for Physics for his work on magnetohydrodynamics. He and other plasma pioneers identified on cosmic scales the same effects that they were able to create in laboratories, and established that plasma phenomena could be scaled through an astonishing 14 orders of magnitude. In place of the gravity-dominated picture, he proposed an earlier plasma epoch in the evolution of the cosmos, in which electromagnetic forces played the initial role in collecting matter together to create the densities in which gravity would become a significant factor only later.

Far from being an insulating vacuum, space was permeated by plasma, which can carry electric currents. Electric currents produce magnetic fields. Interesting things happen when currents flow through a plasma.

From basics, currents flowing in the same direction in a pair of parallel conductors will induce circular magnetic fields and produce an attractive force between them.

In a plasma, where the charge carriers are free to move laterally, the currents are drawn together into a constriction called a “pinch,” or frequently, “Z-pinch.” It can be very powerful. Also, the negative electrons and positive ions experience forces in opposite directions as they move inward and interact with the circular field of the other filament. Since the electrons have a far higher mobility than the ions, this redistributes and separates the charges .

The resultant forces act off-center, causing the filament to rotate about each other as they converge—like approaching ice skaters linking arms as they pass.

As the two filaments move closer together and rotate faster, the excess charges on the inner sides, moving in opposite directions, produces a short-range repulsive force.

The net force is attractive at long ranges but repulsive at close range. On the right are two current filaments in a lab demonstration just beginning to pinch together and twist.

The short-range repulsion prevents the filaments from merging and preserves their identity, resulting in a twisted, braided structure. It could interact in turn with similar structures to form "ropes" on a larger scale. Braided structures like this are the signature of electric currents in plasmas. They occur at all scales, from microscopic to cosmological. Let's look at some.

A fusion research device for generating intense plasmas. A large current is discharged across the two concentric cylinders, which ionizes the plasma and forms usually eight to ten pairs of current filaments, each about a millimeter in diameter, which fountain outward from the right-hand end. The oppositely-rotating vortex pairs pinch together into a doughnut-shaped filamentary knot called a plasmoid, whose field contains all the energy that was stored in the magnetic field of the whole device, a million times bigger in volume. The spiraling electrons start to radiate away the energy, causing the current to drop, collapsing the magnetic field and generating a electric field which shoots two high-energy beams out along the axis of the toroid in opposite directions, electrons in one direction, ions in the other, each a micron across.

Here's a view down the barrel. No need to comment on the filamentary structure.

Plasma Ball

Scaling up by a factor of getting on for a million, the plasma ball that you see in novelty shops. You can see the smaller filaments combining and getting thicker toward the center.

Up by another million—a spectacular view of the southern aurora from space, which Birkeland first recognized as electrical. Currents flowing in space plasmas are called Birkeland currents.

From Earth scale to Sun scale. A part of the Sun's visible surface or photosphere. The conventional model applies the physics of fluid dynamics as we know it here on Earth, and explains the granulated appearance as being the tops of convection columns. The trouble with that is that at the temperatures and densities involved, the motion should be violently chaotic, not ordered and structured. The quantity that defines a critical limit beyond which orderly motion gives way to complex turbulence is known as the Reynolds Number. Under the conditions prevailing in the photosphere, it's exceeded by a factor of 100 billion. That's not a trivial discrepancy. Similarly, the Rayleigh Number, specifically devised as a criterion for the formation of convection cells, is exceeded by a factor of 100,000.

But here's a sunspot, where a hole penetrates through the photosphere to the interior. The filamentary structure at the sides starts to become apparent. In fact it's suggestive of the phenomenon know as "anode tufting" in arc discharge tubes. When the current at an anode becomes excessive, further ionization of the medium sets in, causing secondary, brighter plasmas to form inside the first. The bright tufts repel each other and pack into polygonal patterns that appear and then disappear to be replaced by new ones—just as is observed on the Sun.

The sunspot edge at higher magnifications. Plasma engineers have no hesitation in seeing plasma structures shaped by electrical forces. On the right, for comparison, is a high-current laboratory hot plasma vortex.

And in case there could be any doubt about it, here's a false-color image of the same sunspot at higher altitude, showing the filamentary structure that's not visible optically.

Solar Prominence

Again at the Sun, but now above and beyond the surface. A NASA spokesman described prominences as "loops of magnetic field with hot gases trapped inside." Astronomers apparently treat magnetic fields as primary entities in their own right, without giving recognition to the currents that are necessary to produce them. The structure matches laboratory discharges using intense currents almost parallel to the magnetic field—known as “spheromaks.”

Magnetic fields arise only from electric currents. It has become fashionable to talk about magnetic field lines "breaking" and reconnecting" as the source of the energy that drives these eruptions. But field lines are simply representations that point the direction of a field and indicate its strength by their spacing—like contours on a map. They are not physically real things that can break and reconnect.

According to the standard gravity-bound convection model, the Sun ought to end at the photosphere, with not much going on beyond it except energy being radiated away. Certainly, there's no prediction of, or reason for, any complex structure.

But this is what the corona looks like in ultraviolet.

Going beyond the Solar System, Cygnus Loop is a supernova remnant in the constellation Cygnus. The aurora-like curtains and filaments have far more the characteristics of electrical currents flowing through plasma than the mechanical processes resulting from "acoustic shock" that the standard theory talks about. To the right is a close-up of one of the filaments showing the Birkeland twists quite clearly. To say that neutral gases in a vacuum do not form such structures in an understatement. Cygnus Loop also exhibits polarization of light, acceleration of relativistic electrons, and X-ray hot spots—all expected from electrified plasma.

Double Helix Nebula

A striking example of braided Birkeland currents on a celestial scale. The Double Helix nebula, near our own galactic center. It even looks like DNA—I'm sure a science-fiction writer somewhere could go places with that.

Plasma phenomena scale up not only through many orders of magnitude, but also in time. Processes that take billionths of a second in laboratories can be recognized unfolding over centuries or more astronomically. We began this quick tour up through scales of magnitude with the plasma focus device and its sub-millimeter-size tornadoes of current.

Here it is again, alongside a Hubble image of the planetary nebula NGC 6751. So what are we seeing? Gravity, which produces featureless clumps of matter? Or electricity?

Stars are supposed to form out of dust and gas contracting from an accretion disk under self-gravitation.

But there are many problems with this. Simulations and calculations indicate that matter would tend to disperse rather than form into clumps. Then there's the question of how the angular momentum comes to be concentrated in the planets. In the case of our own Solar System, 97 percent of it is in Jupiter and Saturn, one percent distributed among the smaller fry, leaving about two percent in the Sun itself. A cloud contracting and speeding up under gravity should concentrate most of the angular momentum in the Sun, giving it a rotation period of something like 13 hours instead of the 28 days that it has. And then there's the question of where it came from in the first place. A cloud of randomly moving matter should contain very little net angular momentum.

Alfvén and his intellectual descendants saw Birkeland currents in space as not merely coincidental with the existence of stars, but responsible for their formation. The electromagnetic force diminishes with distance, in contrast with gravity, which decreases as the square of distance. This makes electromagnetic forces far more effective for gathering and organizing widely dispersed clouds of dust and gas. And rotation is the natural outcome, as we saw earlier.

Stars are concentrated along the spiral arms of galaxies like ours, and that's also where new stars come into existence.

The electrical model proposes that these arms form the paths of currents flowing along a galactic-scale circuit between the rim and the axis. Stars form like beads along a thread, where matter is being compressed, rotated, and heated by powerful electrical Z-pinches.

Here are some examples of where you can see it happening.

The Butterfly nebula. A bipolar formation of converging embedded current cylinders producing glow discharge mode in the plasma for a distance greater than the diameter of our Solar System. The close-up of the neck shows a dusty toroid occluding the star at the center. The physics of plasmas predicts such a central torus. Note the embedded hourglass shapes. We'll meet them again later.

Bug nebula

Here's the Bug nebula. The pinch effect and general hourglass form are plainly visible. It spans about a third of a light-year. The light from the star is rich in ultraviolet—one of the signatures of an electric discharge.

Spiders Web nebula

And the same kind of thing seen from the side. We're looking through two cones meeting point-to-point. The geometry resembles the electrodes of a carbon arc—which perhaps in many ways it is.

Heresy is probably one of the most extreme expressions of flexible thinking. While we're at it, we might as well follow the possible implication of what we've been talking about, and ask, if cosmic electrical currents provide the driving force to compress and form stars, might they not supply the power that lights them too?

"Everyone knows," because we learned it at school and all the textbooks and encyclopedias say so, that the Sun is powered by thermonuclear reactions deep in the core, that were ignited by gravitational compression. But despite its being generally regarded as established fact, the theory in fact has some serious difficulties.

The standard model originated from the work of the English scientist Sir Arthur Eddington in the 1920s. Since astronomical objects were viewed—and to a large degree still are—as isolated bodies, an internal heat source was needed that could maintain the Sun's energy output and support an equilibrium against compression. In the following decade, the physics of hydrogen-helium fusion was worked out. Since the Sun was known to consist predominantly of hydrogen that seemed to settle it, and all observational data since has been interpreted in terms of that assumption. But the essence of flexible thinking, surely, is to be able to question core assumptions objectively, instead of defending them reflexively.

For a start, the calculated density at the center of the Sun is about a hundred times too low to ignite a thermonuclear process. At the indicated temperature of 13,000,000 K, protons wouldn't have enough energy to overcome their mutual repulsion. The response is to invoke quantum-mechanical tunneling. That permits fusion only when the protons approach each other head-on, which occurs only in a minuscule proportion of cases. But for as long as an interior energy source is insisted on, there is no alternative, and so the conclusion is drawn that the requisite conditions must exist "somehow."

We've already seen that the convection-cell explanation for the appearance of the photosphere is difficult to reconcile with just about everything that's known about convection. And the gravity-bound model predicts none of the complex structures seen beyond the surface, in the corona. In addition, the Sun has been found to expand and contract rhythmically through an amplitude of about 10 km with a period of 2 hours, 40 minutes. This is almost precisely what would be expected if it were equally dense throughout, like a balloon, rather than progressively denser toward the center. But an isodense model would be far too cool for core fusion.

And then, of course, there's the question of neutrino count, which I'd imagine most people here are familiar with. The basic Proton-Proton reaction produces low-energy neutrinos and involves a rarer beryllium-producing side reaction that releases a higher-energy neutrino. Enormous expense and effort were invested over the last twenty years or so in the construction of neutrino observatories in South Dakota, Japan, and Canada. The low-energy counts came out so low as to make meaningful interpretation impossible, and the high-energy counts were