Theodor Kaluza

“ If one remains in for simplicities sake (a circular disc rotating in its plane around the center, angular velocity = 1) , then one has a bundle of coaxial helical lines of same pitch ("helical bundle") . The helical bundle is not straightly intersected [anorthotom] ; consequently we are at first not speaking about a proper geometry in the previous sense, nor about a "rest shape" of the rotating disc. One can only speak about a constantly Euclidean "individual geometry" and a "individual shape", related to a certain point of the disc (see the theory of linear complexes) . ”

“ A more detailed investigation gives the magnitude of the error of closure (measured in proper time) as equal to the double proper-content of the time-comparison curve. From the existence of the error of closure, the theoretical possibility of a demonstration of Earth's rotation by purely optical or electromagnetic experiments is given. ”