Quantum Theory: Paul Dirac
Discussion of quotes on the Evolution of Quantum Theory from Paul Dirac.
Explaining Dirac's theoretical discovery of Positron as an Opposite phase Spherical Standing Wave (thus explaining matter / antimatter annihilation).

Quantum Theory: Paul Dirac (1902 - 1984)

When one looks back over the development of physics, one sees that it can be pictured as a rather steady development with many small steps and superposed on that a number of big jumps. These big jumps usually consist in overcoming a prejudice...And then a physicist has to replace this prejudice by something more precise, and leading to some entirely new conception of nature. (Paul Dirac, Quantum Theory)

This statistical interpretation is now universally accepted as the best possible interpretation for quantum mechanics (quantum theory), even though many people are unhappy with it. People had got used to the determinism of the last century, where the present determines the future completely, and they now have to get used to a different situation in which the present only gives one information of a statistical nature about the future.
A good many people find this unpleasant; Einstein has always objected to it. The way he expressed it was: "The good God does not play with dice". Schrodinger also did not like the statistical interpretation and tried for many years to find an interpretation involving determinism for his waves. But it was not successful as a general method.
I must say that I also do not like indeterminism. I have to accept it because it is certainly the best that we can do with our present knowledge. One can always hope that there will be future developments which will lead to a drastically different theory from the present quantum mechanical theory and for which there may be a partial return of determinism. However, so long as one keeps to the present formalism, one has to have this indeterminism.
(P.A.M. Dirac, on Quantum Theory, "The Development Of Quantum Mechanics" Conferenza Tenuta il 14 Aprile 1972, in Roma, Accademia Nazionale dei Lincei, 1974)

It seems that if one is working from the point of view of getting beauty in one's equations, and if one has really a sound insight, one is on a sure line of progress. If there is not complete agreement between the results of one's work and experiment, one should not allow oneself to be too discouraged, because the discrepancy may well be due to minor features that are not properly taken into account and that will get cleared up with further development of the theory. (Paul Dirac, Scientific American, May 1963)

I must say that I am very dissatisfied with the situation, because this so called good theory does involve neglecting infinities which appear in its equations, neglecting them in an arbitrary way. This is just not sensible mathematics. Sensible Mathematics involves neglecting a quantity when it turns out to be small - not neglecting it just because it is infinitely great and you do not want it! (Paul Dirac, On Quantum Mechanics and Mathematics, 1937)

Quotes attributed to Paul Dirac

Art and science have their meeting point in method. (Paul Dirac)

God used beautiful mathematics in creating the world. (Paul Dirac)

In science one tries to tell people, in such a way as to be understood by everyone, something that no one ever knew before. But in poetry, it's the exact opposite. (Paul Dirac)
The fundamental laws necessary for the mathematical treatment of a large part of physics and the whole of chemistry are thus completely known, and the difficulty lies only in the fact that application of these laws leads to equations that are too complex to be solved. (Paul Dirac)Quantum-Physics

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