Thermodynamics and Energy


A Re-examination of Kirchhoff's Law of Thermal Radiation in Relation to Recent Criticisms: Reply

Authors: Pierre-Marie Robitaille

Recently, Robert J. Johnson submitted an analysis of my work, relative to Kirchhoff’s Law of Thermal Emission (R.J. Johnson, A Re-examination of Kirchhoff’s Law of Thermal Radiation in Relation to Recent Criticisms. Prog. Phys., 2016, v. 12, no. 3,175–183) in which he reached the conclusion that “Robitaille’s claims are not sustainable and that Kirchhoff’s Law and Planck’s proof remain valid in the situations for which they were intended to apply, including in cavities with walls of any arbitrary materials in thermal equilibrium”. However, even a cursory review of Johnson’s letter reveals that his conclusions are unjustified. No section constitutes a proper challenge to my writings. Nonetheless, his letter is important, as it serves to underscore the impossibility of defending Kirchhoff’s work. At the onset, Kirchhoff formulated his law, based solely on thought experiments and, without any experimental evidence (G. Kirchhoff, Uber das Verhaltnis zwischen dem Emissionsvermogen und dem Absorptionsvermogen der Korper fur Warme und Licht. Pogg. Ann. Phys. Chem., 1860,v. 109, 275–301). Thought experiments, not laboratory confirmation, remain the basis on which Kirchhoff’s law is defended, despite the passage of 150 years. For his part, Max Planck tried to derive Kirchhoff’s Law by redefining the nature of a blackbody and relying on the use of polarized radiation, even though he realized that heat radiation is never polarized (Planck M. The Theory of Heat radiation. P. Blakiston’s Son & Co., Philadelphia, PA, 1914). In advancing his proof of Kirchhoff’s Law, Max Planck concluded that the reflectivities of any two arbitrary materials must be equal, though he argued otherwise (see P.-M. Robitaille and S.J. Crothers, “The Theory of Heat Radiation” Revisited: A Commentary on the Validity of Kirchhoff’s Law of Thermal Emission and Max Planck’s Claim of Universality. Prog. Phys., 2015, v. 11, no. 2, 120–132). Planck’s Eq. 40 (ρ=ρ’), as presented in his textbook, constituted a violation of known optics. Planck reached this conclusion, because he did not properly treat absorption and invoked polarized light in his derivation. Planck also made use of a carbon particle, which he characterized as a simple catalyst. This conjecture can be shown to result in a violation of the First Law of thermodynamics, if indeed, all cavities must contain black radiation. In the end, while Johnson attempts to defend Planck’s proof, his arguments fall short. Though the author has argued that Kirchhoff’s law lacks both proper theoretical and experimental proof, Johnson avoids advancing any experimental evidence from the literature for his position. It remains the case that experimental data does not support Kirchhoff’s claims and no valid theoretical proof exists.

Comments: 20 pages. First published in: Progress in Physics, 2016, v. 12, no. 3, 184-203.

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[v1] 2016-02-01 08:44:56

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