**This was originally “tweeted” on August 23rd, 2012**
A theory is a formal description of nature (meaning, a mathematical frame set with a link to lab stuff) which can make predictions of observations. Verification of these predictions are made through the trials of experiments and comparing what the theory says about its outcomes and what is really measured. This is often not as simple as it sounds as often the observations are somehow indirect, and the instrumentation (with their own theory of functioning) is needed. Also, simplifications are often needed to work out the results and so on. That’s why experimental science is not as simple as it sounds in college textbooks. Experimental observations can be disputed. However, at the end of the day, if there is a clear difference between what a theory predicts and what is unambiguously experimentally observed, then the theory is problematic.
Bear in mind, an *interpretation* of a theory is the act of giving an ontological meaning to the elements of a theory. It is a way of “…looking at the meaning of the mathematical concepts of a theory”. An interpretation of a theory doesn’t make any predictions different from the theory.
If you were to come across two rivaling interpretations of the same theory, normally they’ll make exactly the same observational predictions. Understand that no experiment ever can make a distinction between two different interpretations of the same theory.
Think of the orthodox Copenhagen interpretation: it makes exactly the same experimental predictions as does the Many-Worlds interpretation of the same theory, [quantum theory]. For one to say “…that an experiment favors this or that interpretation” is flawed [fundamentally]. An experiment can suggest the validity of a theory, or, it can falsify a theory. But it cannot distinguish between two interpretations [of the same theory].
Certain interpretations, however, can suggest, or be more robust with respect to modifications or limitations of a theory. For example, in reference to the Many-Worlds interpretation to continue to hold it would be necessary that quantum theory be applicable on a human scale (currently unverified). It will break down if ever quantum theory is falsified on that scale (this hasn’t happened as of yet either). On the other hand, the Copenhagen interpretation is more flexible, case in point, there is an undefined zone of transition between the “quantum realm” and the “classical realm”. Hence, one could accommodate a falsification of quantum theory on a mesocopic scale (this also hasn’t happened yet).
As long as quantum theory is strictly valid both the Many-Worlds interpretation and the Copenhagen interpretation remain indistinguishable. If quantum theory is falsified at a mesocopic scale then it will probably be difficult to have a Many-Worlds-like interpretation of the *new* theory that will replace the quantum theory while it might still be possible to cling to a Copenhagen-like interpretation of the *new* theory that will replace the quantum theory on the mesocopic scale.
Keep in mind that experimental predictions belong in the realm of a theory, not its interpretations. Therefore, only a theory can be falsified, not its interpretation.
The Afshar experiment falls into the trap of assigning probabilities to non-measured wave functions. This is something that is at the basis of just about all quantum paradoxes (implicitly assuming conversation of simultaneity is at the basis of those paradoxes).
Afshar thought that Einstein was right [about quantum mechanics]. Einstein was wrong.
The Afshar “paradox” [experiment] is that “detecting through which hole came the photon” is suppose to make the photon have a particle hat when the fact that the grid doesn’t seem to perturb the light when both holes are open seems indicative of the photon “wearing” the wave hat.
Some forget to realize that that’s a misunderstanding of how quantum mechanics functions [hence what I stated about Einstein's view of quantum mechanics]. This is very common in a lot of collegiate textbooks and a lot of your Big Brains in Academia have taken it upon themselves to integrate it in education.
What is true in regards to quantum theory is that wave functions tend to evolve into probability distributions at the act of irreversible observation [particle behavior, so to speak].
I’m going to cut this tweet short, so I’m not going to go into superposition states–at least not today. But I will say that Einstein viewed quantum mechanics as, at least, “…not indicating [the existence] of other universes” (paraphrased). Of course, for those of you who are familiar with quantum mechanics, the aforementioned “holes” is in reference to the double-slit experiment. Nevertheless, Afshar’s experiment was an attempt to prove or, to say the least, back-up Einstein’s viewpoint.