" The magnetic force of a plasma thread increases with the velocity of the plasma, causing a positive feedback cycle: as the threads move closer, they are pulled together faster, increasing the magnetic force on them, pulling them still faster. As they move together, the angular momentum of the plasma causes centrifugal force that resists contraction, but the filaments are able to carry away excess angular momentum, whereas gravity cannot (p. 44).
This process, understood from numerous laboratory observations, has implications on larger scales. The solar system, for instance, formed from the gravitational collapse of a vast gas cloud. As this cloud contracted as a result of gravity, it started spinning. If gravity were the only force involved, the process would have stopped there. The centrifugal force of the cloud would have resisted further collapse, with the solar system stabilizing as a diffuse cloud of gas, roughly twice its present diameter. But the solar system did form. Hannes Alfvén, the father of plasma cosmology, theorized that the inner part of the protostellar plasma cloud spun faster than the outer part, generating an electric current, "flowing out along the solar magnetic field lines, through the cloud and back to the sun at its equator" (p. 189). The interaction of the currents and magnetic fields caused the inner cloud to slow down, and the outer cloud to speed up, transferring angular momentum out of the system, and allowing further collapse.
By this mechanism, the early solar system lost 99.9% of its angular momentum, allowing the sun the collapse to the point at which it was able to ignite. The magnetic field action does not stop there, though. The sun, which represents over 99% of the mass of the solar system, retains only two percent of its angular momentum, while Jupiter has 70%, and Saturn has 27%. Two planets, which represent about a thousandth of the mass of the solar system, possess nearly all of its angular momentum (p. 188). In 1972, Alfvén and Gustaf Arrhenius developed a model of the early solar system in which self-pinched filaments swept through the dense protoplanetary plasma, their concentrated magnetic fields transferring angular momentum from the sun to the protoplanetary disk, pinching the plasma together into planets, which use the same process to form satellites (p. 209). The existence of planetary currents and filaments was confirmed in the sixties and seventies, when space probes detected them around Earth and the outer planets, exactly as Alfvén and his colleagues predicted (p. 45). This process may also be the key to solving a long-standing mystery: the origin of the moon. I propose that an analysis of the angular momentum of the Earth and moon will reveal whether the moon formed with the Earth, or was captured later."