Eugene N. Parker

S. Chandrasekhar Distinguished Service Professor Emeritus
Department of Astronomy and Astrophysics
The University of Chicago

Space Plasmas, Magnetic Fields, the Principles of Physics, and Human Nature

Link to video presentation (MP4 stream)

The development of the universal hydrodynamics of the bulk flow of a gas, with or without interparticle collisions, is presented briefly as a preliminary step for treating the large-scale dynamics of a magnetic field embedded in a partially or wholly ionized gas – magnetohydrodynamics. The basic conclusion is that the field is carried bodily with the gas, based on the simple fact that the ionized gas cannot support any significant electric field in its own moving frame of reference. Then we turn to the diverse and contrary ideas that have grown up around this simple principle, based on personal convictions about electric currents and electric fields. In recent years these fantasies have blossomed into electrical theories for the magnetic activity observed in the Sun and Galaxy, published in such jourrnals as IEEE Transactions on Plasma Physics. Forgotten is the fact that there can be no significant electric field in the moving frame of reference of the ionized gas. Numerous contemporary laboratory plasma physics experiments driven by large electric potentials produce luminous plasma “objects” with shapes superficially resembling magnetic coronal loops observed on the Sun and open spiral galaxies, often interpreted as demonstrating the electrical nature of astrophysical activity. The curious psychological aversion to the conclusions dictated by the basic principles of physics is noteworthy.

References:
Parker, E. N. 2007, Conversations on Electric and Magnetic Fields in the Cosmos, Princeton University Press, Princeton

D. E. Scott, 2007, Real Properties of Electromagnetic Fields and Plasma in the Cosmos., IEEE Trans. Plasma Sci. 35, No. 4.

The Three Thousand Year History of the Solar Wind Concept

Link to video presentation (MP4 stream)

The multitude of concepts essential for recognition of the solar corpuscular radiation as hydrodynamic expansion of the solar corona has developed over the past three millennia. We hardly think of the separate concepts in this day and age, but the multitude contains several controversial and even heretical ideas when they were first recognized. With each advance some small amount of the primitive intellectual rubbish was left behind, including the still widely stated idea that a cloud of collisionless particles cannot be treated as a hydrodynamic fluid. The outstanding problem facing space science and solar wind theory today is the illusive heating of the solar corona associated with the various phases of the wind.

Reference:
E. N. Parker, 2001, A History of the Solar Wind Concept, The Century of Space Science, Kluwer Academic Publishers, pp. 225 – 255.