Abstract

Kant said that we were never be able to know about the true nature of matter. The things in themselves would remain unknown to us. There is a similar problem in quantum mechanics. You cannot provide directly any property to a physical state represented by a ray in a Hilbert space. The general theory of relativity teaches time and space were not how they appear to us, but claims to know that in fact space and time would belong to a curved space-time. It turned out in the last decades that it is extraordinary difficulty to combine both theories. Based on quantum mechanics I argue in this paper that the things in themselves remain unknown. There is probably no substance which we can call space-time.