Thermodynamic and kinematic origins of anisotropic relativity.

We recently developed the framework of anisotropic relativity through a perhaps surprising path - the new theory of thermodynamic relativity. Here we show that there is another, and in retrospect more obvious path, which is through asynchronous kinematics. We develop this framework through three progressive thought experiments: (1) Stationary observers that exchange a signal of particles and light beams in one-way opposite directions; (2) Nonstationary observers that exchange light signals; and (3) Nonstationary observers that exchange a signal of particles and light beams. Through these, we show the addition rule of one-way velocities, and that this is the same addition rule derived from thermodynamic relativity. We conclude that the broadest formalism of special relativity - the one derived from thermodynamic relativity that corresponds to linear Lorentz transformations, is actually connected with asynchronous kinematics and describes the asynchronous adaptation of Einstein's special relativity, or simply, the anisotropic relativity.