Werner Heisenberg

The developments that triggered this monumental convulsion involved the formulation of two dramatically new theories. The first was a theory of space, time and motion, called relativity. The second was a theory of the nature of matter and of the forces that act upon it. The latter had its origins in Max Planck's observation that electromagnetic radiation is emitted in discrete packets, or quanta. In the 1920S this ‘quantum theory' was elaborated into a general quantum mechanics.

The central theme of Heisenberg's exposition, which is based on his 1955—6 Gifford lectures at the University of St Andrews, is that words and concepts familiar in daily life can lose their meaning in the world of relativity and quantum physics. Thus questions about space and time, or the qualities of material objects such as their positions, which seem entirely reasonable in everyday discourse, cannot always be meaningfully answered. This in turn has profound implications for the nature of reality and for our total world view.

the theory tells us that there is no absolute universal time, nor is there a universal concept of simultaneity