# Scaling, Scattering, and Blackbody Radiation in Classical Physics

## TL;DR

This paper explores how classical physics, when considering relativistic effects, can explain blackbody radiation spectra, highlighting the importance of relativistic scatterers in deriving the Planck spectrum.

## Contribution

It demonstrates that fully relativistic scatterers within classical physics can produce the Planck spectrum, contrasting with nonrelativistic approaches that yield the Rayleigh-Jeans spectrum.

## Key findings

- Relativistic classical electrodynamics leads to the Planck spectrum.
- Nonrelativistic models produce the Rayleigh-Jeans spectrum.
- Relativistic scatterers are essential for classical derivation of blackbody radiation.

## Abstract

Here we discuss blackbody radiation within the context of classical theory. We note that nonrelativistic classical mechanics and relativistic classical electrodynamics have contrasting scaling symmetries which influence the scattering of radiation. Also, nonrelativistic mechanical systems can be accurately combined with relativistic electromagnetic radiation only provided the nonrelativistic mechanical systems are the low-velocity limits of fully relativistic systems. Application of the no-interaction theorem for relativistic systems limits the scattering mechanical systems for thermal radiation to relativistic classical electrodynamic systems, which involve the Coulomb potential. Whereas the naive use of nonrelativistic scatterers or nonrelativistic classical statistical mechanics leads to the Rayleigh-Jeans spectrum, the use of fully relativistic scatterers leads to the Planck spectrum for blackbody radiation within classical physics.