Horace. Isn't it a bit presumptuous to assume isotropic magnetic fields in areas of space, based on local measurements? Magnetic Mirrors, and the Focus Coils of a CRT for example can keep charged particles in a straight line.
Fred > [Original Message] > From: Horace Heffner <[EMAIL PROTECTED]> > To: <[email protected]> > Date: 3/18/2006 8:25:43 AM > Subject: Re: Cold Fusion & Supernova 1987A] > > > On Mar 17, 2006, at 3:04 PM, Bob Fickle wrote: > > > Yes, they will follow the field lines; but there's not much large- > > scale order to the galactic magnetic field, so it's more a > > diffusion process, once the particles leave the supernova's > > immediate area. There's no significant recombination- not enough > > electrons moving close to the same speed, and even those that did > > combine would be broken apart again by collisions with atoms in the > > interstellar medium. > > With an interstellar density of 1 atom/cm^2 this does indeed appear > to be true. The pulse will remain in plasma form. However, this > then also negates the effect of any ambient magnetic field. > > As the fast electrons fly away from the nuclei a large E gradient > develops and the electrons and > nuclei eventually rejoin. Their relative motion is thermalized, but > the net outward kinetic energy remains. Further, the initial ambient > magnetic field is cancelled by the plasma action. As long as the > plasma density is much larger than the interstellar matter density > the plasma pulse should travel fairly unimpeded. I haven't done the > calculation, but I would expect this distance to be a lot less than > 150,000 ly. > > Suppose we view the explosion from the north pole direction of the > ambient magnetic field. The initial ambient magnetic field lines > point toward us. The plasma that comes toward us is unimpeded by the > ambient magnetic field. Plasma traveling in (or with a component > motion in) a plane perpendicular to the ambient magnetic field has an > ambient field canceling current generated in it. Outbound nuclei are > bent in a clockwise manner by the Lorentz force, electrons are bent > in a counterclockwise direction. This creates a clockwise current > from our perspective. A clockwise current, by the right hand rule, > generates a magnetic field that cancels the ambient field that points > at us. Some of the lateral motion due to the induced current is lost > to thermalization, but for the most part the plasma will retain the > bulk of its outbound velocity and kinetic energy. The tiny > interstellar magnetic field is cancelled by a nominal current > density, thus little heating and little loss of kinetic energy occurs. > > > Last I heard, cosmic rays were believed to have an average age in > > the galaxy of a few million years- based on ratios of Li/Be/B > > isotopes produced in transit. > > But this fact implies very little thermalization of, a very long mean > free path for, the cosmic rays. They only have to travel 150,000 > years to get here, not millions. > > > > Since the LMC is actually outside our galaxy, I think it would be > > safe to add a few million more. > > If nothing thermalizes the plasma pulse outbound motion, or at least > some component of it, then some kind of material shock wave should > immediately follow the light pulse and build. > > Horace Heffner
