Monday, September 9, 2013

Paradigm argument for quantum interpretation

Papers on crackpot physics often start by invoking Kuhnian paradigm shifts, Galileo, and Einstein.

A new paper on a peculiar interpretation of quantum mechanics, Rovelli's relational quantum mechanics, monism and quantum becoming, starts:
According to Kuhn (1996, p. 85), a radical change in our physical worldview is not just due to the invention of a mathematical formalism or to new empirical information coming from novel experiments, but it also implies a thorough modification of the fundamental concepts with which we interpret the world of our experience. This is particularly evident in the scientific revolution ushered by Galileo (Koyré 1978), which consisted essentially in the discovery of the equivalence between uniform motion and rest, two notions that had always been sharply contrasted, but whose indistinguishability is essential to attribute our planet a counterintuitive state of motion.

The same moral applies to Einstein’s Special Theory of Relativity (STR). Not by chance, Rovelli’s relational interpretation of quantum mechanics (Rovelli 1996, 1998) draws inspiration from the latter theory, by correctly claiming that Einstein’s 1905 paper did not change the existing physics, but provided a new interpretation of an already available formalism. As is well-known, this interpretation was obtained via a critique of an implicit conceptual assumption - absolute simultaneity - that is inappropriate to describe the physical world when velocities are significantly close to that of light. It is important to note that it was only thanks to the abandonment of such an assumption – that depends on the “manifest image of the world” (Sellars 1962), and in particular on that belief in a cosmically extended now that percolated in Newton’s Principia - that Einstein could postulate the two axioms of the theory, namely the invariance of the speed of light from the motion of the source and the universal validity of the principle of relativity. What is relevant here is to recall that not only do these axioms imply the relativization of velocity, already theorized by Galilei, but also that of the spatial and temporal intervals (separately considered), a fact that became particular clear with Minkowski (1908) geometrization of the theory.

The historical theme of the relativization of quantities that were previously regarded as absolute is central also in Rovelli’s relational approach to quantum mechanics (RQM), whose metaphysical consequences, strangely enough, have not yet been explored in depth,
Because of arguments like this, we ought to get the history right. The above history is confused.

It is true that Einstein's 1905 paper did not change existing physics. But it did not provide a new interpretation either. That was done by Poincare in 1905, and extended by Minkowski in 1908. Einstein's theory was called the Lorentz-Einstein theory, and neither Einstein nor anyway else saw any significant difference between Lorentz's and Einstein's interpretation.

The author is promoting a new interpretation as a Kuhnian paradigm shift. The advantage of this is that no evidence, experiment, or logical argument is needed. No change to existing physics is needed. According to Kuhn, scientists jump on these shifts as big fads, as the new paradigm is not comparable to the old.

Galileo's main argument for the motion of the Earth was that the motion caused the tides. If he had accepted the relativity of motion, he never would have had his dispute with the Catholic Church. The Pope even asked him to write a book that describes theories of the Earth in motion and at rest, without advocating either as correct. Galileo wrote a book making fun of the Pope as Simplicio, and ridiculed the idea that the Earth could be at rest.

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