Boost Coordinates as Physical and Nonarbitrary

What one should conclude is the opposite of what some authors have asserted in the past. For example, they claimed that ``$\cdots$ the coordinates that we use [for computation] are arbitrary and have no physical meaning'' or ``It is the very gist of relativity that anybody may use any frame [in his computations].'' Without delving into the logical fallacies underlying these claims, one should be aware of their unfortunate consequences. They tend to discourage attempts to understand natural processes whose very existence and identity one learns through measurements and computations based on nonarbitrary coordinate frames. The identification of radiation from bodies with extreme acceleration is a case in point. For these, two complementary frames are necessary: an accelerated frame to accommodate the source (boost-invariant sector $I$ and/or $II$) and the corresponding expanding inertial frame (boost-invariant sector $F$) to observe the information carried by the radiation coming from this source. These frames are physically and geometrically distinct from static inertial frames. They also provide the logical connecting link between the concepts and the perceptual manifestations (via measurements) of these radiation processes. Without these frames the concepts would not be concepts but mere floating abstractions.