Quantum Mechanics

Abstract

The theory of relativity has already shaken the foundations of our understanding of the natural world: two events, which for one observer occur at the same time, for another observer are not simultaneous. Quantum mechanics goes still further: a particle is no longer in a definite place at a definite point in time; instead, we have Heisenberg’s; Uncertainty Principle. In the theory of relativity the difficulties come from the fact that the velocity is finite and therefore, according to the observer, two mutually remote events are seen as simultaneous or not simultaneous. In quantum mechanics the uncertainty comes from the fact that one has only a certain definite probability for the occurrence of a particle or other event. Both in relativity and in quantum mechanics it is therefore meaningful only to use such quantities and concepts as one can in principle also measure.