Page:Zur Theorie der Strahlung in bewegten Körpern.djvu/1

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In the following, the attempt was undertaken to derive (from the thermodynamic laws) some theorems of the theory of heat radiation of moving bodies, when possible without the use of special assumptions concerning the essence of radiating heat, and then to apply them. By that, this work is essentially distinguished in terms of method and goal from some publications that appeared in recent times, which treat the same subject from the standpoint of the electromagnetic theory of light, especially on the basis of 's theory. However, the thermodynamic laws are not fully sufficient for the following. Namely, they don't provide the value for the radiation pressure upon a moving surface, which we will require in the following. The existence of such a pressure is a requirement of the second thermodynamic law, and its value for a stationary surface can also be derived from the energy theorem; though this method fails when we try to apply it upon moving bodies. The value of radiation pressure upon a moving surface thus must be derived from a special hypothesis concerning the essence of radiating heat; namely we want to use the value derived by from 's theory. Incidentally, the same value is also given, as we will see further below, from a quite different consideration based on the old theory of light.

We don't want to presuppose about the radiating heat anything other, than that it's a form of energy