Dortmund 2006 – scientific programme

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MP: Theoretische und Mathematische Grundlagen der Physik

MP 12: Klassische Feldtheorie und Diff.geom. + topol. Aspekte

MP 12.2: Talk

Thursday, March 30, 2006, 14:30–15:00, P1-02-111

Inconsistencies of the Common Interpretation of Poynting’s Theorem — •Hannes Hoff — University of Munich

Poynting’s theorem ∂_t u + div S^→ = −j^→ E^→ is a purely mathematical consequence from Maxwell’s equations. As already remarked in Feynman’s lectures (II, chap. 27.3), the interpretation of u as energy density and S^→ as energy flux is tested experimentally for a few special cases only. Considering a simple thought experiment it is shown that the above point of view leads to contradictions due to the inertia of the electromagnetic field of a charge. In addition, some hidden mathematical difficulties are presented. Both approches indicate that the energy density cannot be expressed as a function of E and B alone.