Karl Popper starts out Quantum Theory and the Schism of Physics, as Vol III of Postscript to Logic of Scientific Discovery, with the following declaration:
- Realism is the message of this book.
- It is linked with objectivity…with rationalism, with the reality of the human mind, of human creativity, and human suffering.
- Today, physics is in a crisis….This crisis is roughly as old as the Copenhagen interpretation of quantum mechanics.
- In my view, the crisis is, essentially, due to two things: (a) the intrusion of subjectivism into physics; and (b) the victory of the idea that quantum theory has reached a complete and final truth.
- Subjectivism in physics can be traced to several great mistakes. One is the positivism or idealism of Mach. Another is the subjectivist interpretation of the calculus of probability.
- The central issue here is realism. That is to say, the reality of the physical world we live in: the fact that this world exists independently of ourselves; that it existed before life existed,…and that it will continue to exist long after we have all been swept away.
- The subjectivist dogma was too deeply entrenched within the ruling interpretation of quantum mechanics, the so-called Copenhagen interpretation… this is how the great quantum muddle started….and the whole terminology, introduced in the early period of the theory, conspired to make the muddle worse and worse.
- Another source of the crisis in physics is the persistence of the belief that quantum mechanics is final and complete.
- Philosophers and physicists have been all too prone under the direct influence of Machian positivism, to take up idealist positions…
- One of the things that this volume of the Postscript tries to to is to review many of the past arguments for idealism - which many current physicists still simply take for granted - and to show their error.
Another thing is that Popper deepened the crisis be dwelling deeper into the statistical interpretation of the wave function of Born as the basis of the Copenhagen interpretation. Popper thus identified the crisis but then himself got drowned by the muddle...