Abstract

The key difference between classical mechanics and quantum mechanics, at least in the "orthodox" view of Niels Bohr, is tied to the difference within these two theories of the relationship between the observer and the observed. In classical mechanics the observed system is characterized exactly by what an idealized disembodied observer could know about the system without actually interacting with it, or disturbing it. Thus in classical mechanics the physical system is specified by what could be known by an observer that is conceived to stand apart from the observed system. But according to Bohr science is based on what we can learn from experiment: "The argument is simply that by the word `experiment' we refer to a situation where we can tell others what we have done and what we have learned... This crucial point, which was to become a main theme of the discussions... implies the IMPOSSIBILITY OF ANY SHARP SEPARATION..