söndag 17 maj 2015

Tragedy of Modern Physics: Schrödinger and Einstein, or Quantum Mechanics as Dice Game?

The story of modern physics is commonly told as a tragedy in which the fathers of the new physics of atomistic quantum mechanics Einstein and Schrödinger, were brutally killed by their descendents Bohr, Heisenberg and Born. This story is told again in a new book by Paul Halpern with the descriptive title:
In this story, it is Einstein and Schrödinger who represent the tragedy in their stubborn opposition to the probabilistic Copenhagen interpretation interpretation of the wave function of Schrödinger's equation and their fruitless search for a unified physical field theory free from dice games, which ended in tragical defeat under ridicule from the physics community controled from Copenhagen by Bohr.  

But it is possible that Einstein's and Schrödinger's dream of a unified physical field theory will come true one day, and then the tragedy will instead be modern physics based on dice games. In all modesty this is the working hypothesis I have adopted in my search for a version of Schrödinger's equation allowing a realistic physical interpretation without "quantum randomness". Stay tuned for an update of recent advances in this direction...

In short, one may say that Einstein and Schrödinger seek a mathematical model of physical reality as a question of ontological realism or existence or  what "is",  while Bohr is only interested in what we can "say" (based on what we can "see") as a question of epistemological idealism. In the quest between realism and idealism in physics, one may argue that idealism is failed realism.

The book describes Einstein's and Schrödinger's positions as follows: 
  • As originally construed, the Schrödinger equation was designed to model the continuous behavior of tangible matter waves, representing electrons in and out of atoms. Much as Maxwell constructed deterministic equations describing light as electro­magnetic waves traveling through space, Schrödinger wanted to create an equation that would detail the steady flow of matter waves. 
  • He thereby hoped to offer a comprehensive accounting of all of the physical properties of electrons. 
  • Born shattered the exactitude of Schrödinger’s description, replacing matter waves with probability waves. Instead of physical properties being assessed directly, they needed to be calculated through mathematical manipulations of the probability waves’ values. 
  • In doing so, he brought the Schrödinger equation in line with Heisenberg’s ideas about indeterminacy. In Heisenberg’s view, certain pairs of physical quantities, such as position and momentum (mass times velocity) could not be measured simultaneously with high precision. 
  • Aspiring to model the actual substance of electrons and other particles, not just their likelihoods, Schrödinger criticized the intangible elements of the Heisenberg-Born approach.
  • He similarly eschewed Bohr’s quantum philosophy, called “complementarity,” in which either wavelike or particlelike properties reared their heads, depending on the experimenter’s choice of measuring apparatus. Nature should be visualizable. 
  • Starting in the late 1920s, one of his primary goals was a deterministic alternative to probabilistic quantum theory, as developed by Niels Bohr, Werner Heisenberg, Max Born, and others. 
  • Although he (Einstein) realized that quantum theory was experimentally successful, he judged it incomplete. In his heart he felt that “God did not play dice,” as he put it, couching the issue in terms of what an ideal mechanistic creation would be like. 
  • Agreeing with Spinoza, Einstein sought the invariant rules governing nature’s mechanisms. He was absolutely determined to prove that the world was absolutely determined.
  • Einstein, who had been a colleague and dear friend in Berlin, stuck by Schrödinger all along and was delighted to correspond with him about their mutual interests in physics and philosophy. 
  • Together they battled a common villain: sheer randomness, the opposite of natural order. Schooled in the writings of Spinoza, Schopenhauer— for whom the unifying principle was the force of will, connecting all things in nature— and other philosophers, Einstein and Schrödinger shared a dislike for including ambiguities and subjectivity in any fundamental description of the universe. 
  • While each played a seminal role in the development of quantum mechanics, both were convinced that the theory was incomplete. Though recognizing the theory’s experimental successes, they believed that further theoretical work would reveal a timeless, objective reality.
  • As Born’s, Heisenberg’s, and Bohr’s ideas became widely accepted among the physics community, melded into what became known as the “Copenhagen interpretation” or orthodox quantum view, Einstein and Schrödinger became natural allies. 
  • In their later years, each hoped to find a unified field theory that would fill in the gaps of quantum physics and unite the forces of nature. By extending general relativity to include all of the natural forces, such a theory would replace matter with pure geometry— fulfilling the dream of the Pythagoreans, who believed that “all is number.”
  • The crux of Schrödinger’s rebuttal was to declare that random quantum jumps simply weren’t physical. He argued for a continuous, deterministic explanation instead. continuous, deterministic equation to defend.
  • .....by late 1926 mutual opposition to the notion of random quantum jumps forced the two of them into the same anti-Copenhagen camp. The alliance would be forged once they realized that they were among the few vocal critics of Born’s reinterpretation of the wave equation.
  • After returning to Zurich from Copenhagen, Schrödinger continued to defend his disdain for quantum jumps on the basis that atomic physics should be visualizable and logically consistent. 
  • By the end of 1926, Einstein had drawn a stark line of demarcation between himself and quantum theory. 
  • Einstein appealed to Born, trying to convince him that quantum physics required deterministic equations, not probabilistic rules. “Quantum mechanics yields much that is very worthy of regard,” Einstein wrote to Born. “But an inner voice tells me that it is not yet the right track.
  • The theory . . . hardly brings us closer to the Old One’s secrets. I, in any case, am convinced that He does not play dice.
  • That was not the last time Einstein would make that point. For the rest of his life, in his explanations of why he didn’t believe in quantum uncertainty, he would reiterate again and again, like a mantra, that God does not roll dice.
  • In 1927, Einstein delivered a talk at the Prussian Academy purporting to prove that Schrödinger’s wave equation implied definitive particle behavior, not just dice- rolling. 
  • Despite his prominence, Einstein’s entreaties had little impact on the quantum faithful. 
  • Einstein returned to Berlin a far more isolated figure in the scientific community. While his world fame continued to grow, his reputation among the younger generation of physicists began to sour, as they derided his objections to quantum mechanics. 
  • With experimental findings continuing to support the unified quantum picture advocated by Bohr, Heisenberg, Born, Dirac, and others, Einstein’s dismissal of their views seemed petty and illogical. 
  • Schrödinger was one of the few who sympathized with Einstein’s doubts. They kept up a conversation about ways to extend quantum mechanics to make it more complete. 
  • Einstein complained to him about the dogmatism of the mainstream quantum community. 
  • For example, he wrote to Schrödinger in May 1928, “The Heisenberg- Born tranquilizing philosophy— or religion?— is so deliberately contrived that, for the time being, it provides a gentle pillow for the true believer from which he cannot very easily be aroused. So let him lie there. But this religion has . . . damned little effect on me.” 
  • Although the physics community relocated to the realm of probabilistic quantum reality, leaving Einstein the lonely occupant of an isolated castle of determinism, the press still bathed him in glory. He was the wild-haired genius, the celebrity scientist, the miracle worker who had predicted the bending of starlight. He was something like a ceremonial king who had long lost his influence over the course of events; the media were more interested in him than in the lesser- known workers actually changing science. His every proclamation continued to be reported by the press, if largely ignored by his peers. 
  • the mainstream physics community, who increasingly viewed him as a relic, he remained the darling of the international media...

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