 If this common tale is correct—and there is reason to think it isn’t the full story—then it seems that Einstein must be closer to being correct than Ritz. Ritz’ position appears implausible if only because it implies gases composed of neutral particles will not tend to spread out. That aside, Einstein’s position is attractive if we concentrate on the wave asymmetry mentioned above. Using Popper 1956’s famous mechanical wave example as an analogy, throwing a rock into a pond so that waves on the surface spread out into the future requires every bit the conspiracy that is needed for waves to converge on a point in order to eject a rock from the bottom. However, here it does seem clear that one process is favored thermodynamically and the other disfavored once we have a thermodynamic arrow in hand. Given a solution to the thermodynamic arrow, impulses directed toward the center of a pond such as to eject a rock are unlikely, whereas a rock triggering spherical waves diverging from the point of impact are likely. Here the radiation arrow seems plausibly connected to and perhaps even derivable from the thermodynamic arrow. The main interesting difference is that Popper’s time-reversed pond seems approximately attainable whereas anti-thermodynamic processes seem more absolutely forbidden (or at least dramatically harder to engine, requiring a so-called Maxwell Demon).