The following is a paper by H. Aspden published in Physics Education, v. 28, pp. 340-342 (1993).
THE FIRST LAW OF THERMODYNAMICS
This paper discusses the First Law of Thermodynamics in the context of its alternative expression as the Principle of Conservation of Energy. The author wrote this paper in order to emphasize the scope for energy transfer as between the medium of background space, the aether, and matter and introduced the notion that the local aether has a temperature that we sense as the 3K cosmic background temperature.
The subject of the paper is discussed elsewhere in these Web pages. See Lecture Vc.