Monday, August 25, 2014

No need for quantum interpretation

I just found this sensible March 2000 Physics Today article, Quantum Theory Needs No ‘Interpretation’, by Christopher A. Fuchs and Asher Peres:
Recently there has been a spate of articles, reviews, and letters in PHYSICS TODAY promoting various “interpretations” of quantum theory (see March 1998, page 42; April 1998, page 38; February 1999, page 11; July 1999, page 51; and August 1999, page 26). Their running theme is that from the time of quantum theory’s emergence until the discovery of a particular interpretation, the theory was in a crisis because its foundations were unsatisfactory or even inconsistent. We are seriously concerned that the airing of these opinions may lead some readers to a distorted view of the validity of standard quantum mechanics. If quantum theory had been in a crisis, experimenters would have informed us long ago!

Our purpose here is to explain the internal consistency of an “interpretation without interpretation” for quantum mechanics. Nothing more is needed for using the theory and understanding its nature. ...

The thread common to all the non-standard “interpretations” is the desire to create a new theory with features that correspond to some reality independent of our potential experiments. But, trying to fulfill a classical worldview by encumbering quantum mechanics with hidden variables, multiple worlds, consistency rules, or spontaneous collapse, without any improvement in its predictive power, only gives the illusion of a better understanding. Contrary to those desires, quantum theory does not describe physical reality. What it does is provide an algorithm for computing probabilities for the macroscopic events (“detector clicks”) that are the consequences of our experimental interventions. This strict definition of the scope of quantum theory is the only interpretation ever needed, whether by experimenters or theorists.
Fuchs now promotes Quantum Bayesianism, which is essentially the same as the original Copenhagen interpretation.

I go even farther, and say that probability is just an interpretation, and is not necessary for quantum mechanics. Probability is a mathematical convenience for evaluating experiments in quantum mechanics or any other branch of science, but it is not an observable physical thing.

Quantum mechanics without interpretation has been called the Instrumentalist interpretation
Any modern scientific theory requires at the very least an instrumentalist description that relates the mathematical formalism to experimental practice and prediction. In the case of quantum mechanics, the most common instrumentalist description is an assertion of statistical regularity between state preparation processes and measurement processes. ...

By abuse of language, a bare instrumentalist description could be referred to as an interpretation, although this usage is somewhat misleading since instrumentalism explicitly avoids any explanatory role; that is, it does not attempt to answer the question why.
This article applies it to the Stern-Gerlach experiment. Sometimes the Ensemble interpretation is said to be the minimalist one, but that does not predict individual outcomes.

1 comment:

  1. Simply put, Quantum Mechanics is not mechanics of process at all. There is no mechanism, there is just the observation of quantized outcomes. By itself, this has no explanatory power of any process that involves reality. A class average is not a description or remote comprehension of a student in the class which helped produce the average in aggregate. A random number generator is not a description of a six sided die. A probability 'wave' is a line on a graph that many apparently have no curiosity to ask 'a wave of what?' Probability is nothing but a second hand calculation, like an average, or a mean... It is not a mechanism that describes anything, and it doesn't begin to touch reality since it is merely a limiting abstraction produced by something physicists have basically stopped trying to comprehend. The question should be "Why is energy quantized?" What actual physical mechanism with actual moving parts would produce this effect and why? A six sided die is quantized in its output for the most part, this does not mean you can pretend the die does not exist since you have an output and claim the process by which it is quantized is purely mathematical. Roll the die as many times as you like and watch carefully, it never disappears into probability and collapses back into actuality, and yet it produces a quantized result which is a side effect of its physical structure moving and interacting in time and space. The result is not the cause (or its mechanism), and in no way does the result determine the cause. Math and all calculation depends upon an underlying reality to function (whether you know what it is or not), just as all thoughts, ideas, dreams, hopes, and fears depend upon a brain or similar organ to exist within.
    Mathematical points (or lines) don't (can't actually) spin, or describe cycles and waves or collisions by their movement, interaction, and behavior over a period of time. Structures with physical extension that spin observably do all of these things. Just look at the Bubble chamber tracks picture below for confirmation of this. Quantum mechanics does not need a new 'interpretation' to employ desperate mathematicians trying to justify their ridiculous onanisms to achieve fame, it needs actual mechanics with explanatory power that describe its outcomes and a complete rewrite altogether.
    People who want to do physics (or science) need to stop believing the god damn magician when he waves the wand of probability and pulls a rabbit out of the hat and tells them 'it's magic'. I have no interest whatsoever in being tricked, rather, I wish to find out how the trick was done without resorting to cheesey mathematical miracles and logical sleight of hand. If you want to be fooled, stay away from physics and go watch television.