The Big Bang Never Happened

■ THE COSMOLOGICA.L DEBATE ■Fig. 5.10. In the thirties Alfven calculated that currents above a certainvalue could not easily be carried by plasma. As the magnetic field producedby the current increases (lines going from a to e), the electrons becomemore tangled in the field, until they can no longer go forward. Laterscientists discovered that electrons in force-free filaments are not solimited.hundred-watt light bulb is 120 ohms.) Thus, for concentratedbeams of particles in space, the cosmic plasma is neither purelyconductive nor purely insulative—it has a very earthly resistance.Later, in the fifties, Alfven pointed to less specific restrictionson currents, due to the essentially transient nature of most celestialphenomena. Even currents well below the maximum (the"Alfven current") require a significant amount of time to buildup: energy must be poured into creating a magnetic field, just aswhen a current is suddenly switched off, energy flows from themagnetic field into the current itself. These inductive effects,well known in electrical engineering, are particularly importantin rapid, localized electrical discharges, such as solar flares. Thisenergy drain acts as a resistance, again impeding the free flow ofelectrons. Finally, Alfven, while working with Falthammar onthe revised Cosmic Electrodynamics in the early sixties, realizedthat even for relatively long-term plasma phenomena, the plasma'sresistance can be significant under certain conditions. Mostplasmas in space, he found, are diffuse enough that electrons andions spiral around magnetic field lines without colliding with oneanother. Consequently, it is extremely difficult for the electronsor ions to move perpendicularly to the magnetic field's direction202