Note on the Relativistic Thermodynamics of Moving Bodies

TL;DR

This paper argues that temperature does not have a universal transformation law under Lorentz boosts, implying temperature is frame-dependent and only well-defined in a body's rest frame.

Contribution

It extends microstatistical results to the macroscopic level, showing no intrinsic temperature transformation law under relativistic motion.

Findings

No intrinsic temperature transformation law under Lorentz boosts

Temperature is frame-dependent and only objective in a body's rest frame

Supports the idea that temperature is not an absolute quantity in relativity

Abstract

We employ a novel thermodynamical argument to show that, at the macroscopic level,there is no intrinsic law of temperature transformation under Lorentz boosts. This result extends the corresponding microstatistical one of earlier works to the purely macroscopic regime and signifies that the concept of temperature as an objective entity is restricted to the description of bodies in their rest frames. The argument on which this result is based is centred on the thermal transactions between a body that moves with uniform velocity relative to a certain inertial frame and a thermometer, designed to measure its temperature, that is held at rest in that frame.