"Light signals alone provide the metrical structure of the four-dimensional space-time continuum. The construction may be called light axioms."
Hans Reichenbach was a leading philosopher of science, educator, and proponent of logical empiricism. He founded the Gesellschaft für empirische Philosophie in Berlin in 1928, also known as the "Berlin Circle". Carl Gustav Hempel, Richard von Mises, David Hilbert and Kurt Grelling all became members of the Berlin Circle.
"Perceptual space is not a special space in addition to physical space, but physical space which we endow with a special subjective metric. ...apart from the definition of congruence in physics and that based on perception, there is no third one derived from pure visualization. Any such third definition is nothing but the definition of physical congruence to which our normative function has adjusted the subjective experience of congruence."
Hans Reichenbach"...the order of betweenness does not depend on mutual distances... betweenness is purely a relational order."
Hans Reichenbach"If along the path of truth, success (which was often near-failure unnoticed) is subjected to the same scrutiny and desire for improvement as failure, we may find ourselves in closer proximity to trees."
Hans Reichenbach"Visual forms are not perceived differently from colors or brightness. They are sense qualities, and the visual character of geometry consists in these sense qualities."
Hans Reichenbach"The concept of congruence in Euclidean geometry is not exactly the same as that in non-Euclidean geometry. ..."Congruent" means in Euclidean geometry the same as "determining parallelism," a meaning which it does not have in non-Euclidean geometry."
Hans Reichenbach"Although it is admitted that certain differences cannot be verified by experiment, we should not infer from this fact that they do not exist. ...we are accused of having confused subjective inability with objective indeterminacy."
Hans Reichenbach