2002/06/12 by Timothy H. Boyer, Boyer, Timothy H.
Physics and Astronomy · #Classical Physics (physics.class-ph) #Cosmology and Gravitation Theories #FOS: Physical sciences #General Physics (physics.gen-ph) #Quantum Electrodynamics and Casimir Effect #Relativity and Gravitational Theory #physics.class-ph #physics.gen-ph
paper · pdf · doi:10.48550/arxiv.physics/0206033
22 pages
arxiv created 2002/06/12 · openalex publication_date 2002/06/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A new thermodynamic analysis is presented for the intimate connections between blackbody radiation and zero-point radiation within classical physics. First, using the thermodynamic behavior of an oscillator under an adiabatic change of frequency, we show that the thermodynamic functions can all be derived from a single function of w/T, analogous to Wien's displacement theorem. The high- and low-frequency limits allow asymptotic energy forms involving T alone or w alone, corresponding to energy equipartition and zero-point energy. It is then suggested that the actual thermodynamic behavior for a harmonic oscillator is given by the function satisfying the Wien displacement result which provides the smoothest possible interpolation between scale-decoupled energy equipartition at low frequency and scale-invariant zero-point energy at high frequency. This leads to the Planck spectrum. Second, we turn to radiation in a box with conducting walls and a conducting partition so that the discrete normal mode structure of the box becomes important. The contrasting Casimir energies are explored for the Rayleigh-Jeans and zero-point spectra. The Rayleigh-Jeans spectrum involves no change of energy with partition position, and the zero-point spectrum involves no change of entropy. It is suggested that the Planck spectrum with zero-point radiation satisfies a natural minimum principle which corresponds to greatest independence of the system energy from the position of the partition for a fixed temperature. Numerical calculation is used for confirmation. Third, we review the previous derivations of the Planck radiation spectrum in classical physics, all of which involve zero-point radiation.