
Originally Posted by
Tim Thompson
Just as Einstein rejected much of quantum mechanics, so did Alfven reject much of magnetohydrodynamics.
Alfvén wrote the book on magnetohydrodynamics, and won the Nobel Prize for Physics for it in 1970. I can't find anything to suggest that he rejected MHD. But Alfvén and co-author Carl-Gunne Fälthamma wrote in their book Cosmical Electrodynamics (1952, 2nd Ed.):
"It should be noted that the fundamental equations of magnetohydrodynamics rest on the assumption that the conducting medium can be considered as a fluid."
They continue:
Very roughly we can say that a high-density plasma obeys reasonably well the laws which in Chapter 3 have been derived for liquids and ompressible media. In a medium-density plasma the magnetic field has introduced a pronounced anisotropy and in several respects the plasma becomes quite different from a magnetized fluid . Finally, a low-density `collision-less ' plasma forms a sort of transition to the case of single charges moving in high vacuum

Originally Posted by
Tim Thompson
MHD is not just some simple guess work, it is a full blown theoretical & experimental science, long since verified beyond reproach.
It's an approximation that works well in many situations, but it FAILS in others. Eric Watalis wrote:
About the time when extensive laboratory research started on the interaction between plasmas and magnetic fields, critical views were expressed by Lighthill about the validity of a set of equations called "ideal MHD theory,"; then, as now, normally taken to provide an acceptable description of astrophysical MHD phenomena and magnetic fusion systems. The criticisms have been reviewed here and found to be justified. The corrected MHD fluid equation, expressing approximate magnetic flux conservation in the electron fluid frame, not plasma mass frame, leads to questions about the electric field momentum-transfer distributions between the plasma species. The Lighthill reasoning about this, in conflict with later generally accepted theory, was proved to be correct. (See E.A. Witalis, "
Hall Magnetohydrodynamics and Its Applications to Laboratory and Cosmic Plasma", IEEE Transactions on Plasma Science (ISSN 0093-3813), vol. PS-14, Dec. 1986, p. 842-848.)
This is a fundamental difference between mainstream astrophysicists and the plasma universe people. The plasma universe people have also taken a a fully blown theoretical & experimental scientific approach.
Regards,
Ian Tresman