Astrophysics and Space Science

, Volume 23, Issue 2, pp 261–268 | Cite as

Critique of fluid theory of magnetospheric phenomena

  • W. J. Heikkila


It is pointed out that the fluid theory has been successful in magnetospheric problems (such as the shape of the magnetopause) which involve basic considerations such as the conservation of particles, of momentum, and of energy, but that it is inadequate for other problems (such as the energization of auroral particles). Difficulties arise from the fact that it is not always possible to specify ‘a volume of plasma’ because particles do not remain as neighbours. Misuse of the fluid theory has led to a number of fallacies, such as the idea that the causal order of physical events in cosmic electrodynamics is the reverse of that in the familiar laboratory electrodynamics. This mistaken idea comes from a confusion of a mathematical sequence of calculations with the causal order. Also, the importance of the magnetic field as an active element is over-emphasized. Appreciation of the fact that kinetic theory is the more fundamental seems to be widely lacking. A plea is made for a common sense approach to magnetospheric and auroral problems wherein the fluid theory is used whenever it can, but where it is not expected to be adequate for all purposes.


Magnetic Field Common Sense Kinetic Theory Physical Event Active Element 
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  1. Alfvén, H. and Fälthammar, C. G.: 1971,Cosmic Electrodyn. 2, 78.Google Scholar
  2. Axford, W. I.: 1967,Space Sci. Rev. 7, 149.Google Scholar
  3. Bohm, D. and Gross, E. P.: 1949,Phys. Rev. 75, 1851.Google Scholar
  4. Dessler, A. J.: 1971,J. Geophys. Res. 76, 3174.Google Scholar
  5. Dungey, J. W.: 1958,Cosmic Electrodynamics, Cambridge at the University Press.Google Scholar
  6. Heikkila, W. J.: 1973, ‘Penetration of Particles into the Polar Cap and Auroral Regions’, to be published.Google Scholar
  7. Hines, C. O.: 1963,Planetary Space Sci. 10, 239.Google Scholar
  8. Hines, C. O.: 1964,Space Sci. Rev. 3, 342.Google Scholar
  9. Panofsky, Wolfgang K., and Phillips Melba: 1962,Classical Electricity and Magnetism, Addison-Wesley Publishing Company, Inc.Google Scholar
  10. Parker, E. B.: 1957,Phys. Rev. 107, 924.Google Scholar
  11. Pavkovich, J. M.: 1964, ‘Numerical Calculations Related to the RF Properties of the Plasma Sheet’, Stanford University Report No. 1093.Google Scholar
  12. Roederer, J. G.: 1970,Adiabatic Motion of Geomagnetically Trapped Particles, Springer-Verlag, New York.Google Scholar
  13. Sharber, J. R. and Heikkila, W. J.: 1972,J. Geophys. Res. 77, 3397.Google Scholar
  14. Stix, T. H.: 1962,The Theory of Plasma Waves, McGraw-Hill, New York, p. 107.Google Scholar
  15. Willis, D. M.: 1971,Rev. Geophys. Space Phys. 9, 953.Google Scholar

Copyright information

© D. Reidel Publishing Company 1973

Authors and Affiliations

  • W. J. Heikkila
    • 1
  1. 1.The University of Texas at DallasDallasUSA

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