An Old and a New Tradition

When one speaks today of modern physics, the first thought is of atomic weapons.

The best way to enter into the problems of modern physics may be by a historical description of the development of quantum theory.

• Quantum theory is only a small sector of atomic physics.
• Atomic physics is only a very small sector of modern science.

The most fundamental changes in our concept of reality have taken place in quantum theory.

The new ideas of atomic physics are concentrated and crystallized in the final form of quantum theory.

The enormous and extremely complicated experimental equipment needed for research in nuclear physics shows another very impressive aspect of this part of modern science.

But with regard to the experimental technique nuclear physics represents the extreme extension of a method of research which has determined the growth of modern science ever since Huyghens or Volta or Faraday.

In a similar sense the discouraging mathematical complication of some parts of quantum theory may be said to represent the extreme consequence of the methods of Newton or Gauss or Maxwell.

But the change in the concept of reality manifesting itself in quantum theory is not simply a continuation of the past; it seems to be a real break in the structure of modern science.

Therefore, the first of the following chapters will be devoted to the study of the historical development of quantum theory.