Lecture I
Now in this explanation I have been neatly dividing all that refers to potentials and centric forces and on the other hand all that leads out into the cosmic forces. Yet in the Nature that surrounds us they are not thus apart. You may put the question: Where can I find an object where only centric forces work with their potentials, and on the other hand where is the realm where cosmic forces work, which do not let you calculate potentials? An answer can indeed be given, and it is such as to reveal the very great importance of what is here involved. For we may truly say: All that Man makes by way of machines—all that is pieced together by Man from elements supplied by Nature—herein we find the purely centric forces working, working according to their potentials. What is existing in Nature outside us on the other hand—even in inorganic Nature—can never be referred exclusively to centric forces. In Nature there is no such thing; it never works completely in that way: Save in the things made artificially by Man, the workings of centric forces and cosmic are always flowing together in their effects. In the whole realm of so-called Nature there is nothing in the proper sense un-living. The one exception is what Man makes artificially; man-made machines and mechanical devices.