onsdag 18 januari 2017
Many Worlds Interpretation vs Double Slit Experiment
When I ask David Deutsch what his basic motivation is to believe that the Many Worlds Interpretation MWI of the multi-d linear Schrödinger equation describes real physics, I get the response that it is in particular the single electron double slit experiment, which he claims is difficult to explain otherwise.
But is this so difficult to explain assuming that electrons are always waves and never particles? I don't think so. Here is my argument:
In the single electron double slit experiment a screen displays an interference pattern created by a signal passing through a double slit, even with the input so weak that the interference pattern is created dot by dot as if being hit by a stream of single electron particles.
This is presented as a mystery, by arguing that an electron particle must chose one of the slits to pass through, and doing so cannot create an interference pattern because that can only arise if the single electron is a wave freely passing through both slits. So the experiment cannot be explained which gives evidence that quantum mechanics is a mystery, and since it is a mystery anything is possible, like MWI.
But there is no mystery if following Schrödinger we understand that electrons are always waves and never particles, and that the fact that the effect on the screen of an incoming wave on may be a dot somewhere on the screen triggered by local perturbations. A dot as effect does not require the cause to be dot-like.
It is thus possible to understand the single electron double slit experiment under the assumption that electrons are always wave-like and always pass through both slits and thus can create an interference pattern, in accordance with the original objective of Schrödinger to describe electrons as waves, and then physical waves and not probability waves as in the Copenhagen Interpretation as another form of MWI.
The trouble with quantum mechanics is the multi-d linear Schrödinger equation which describes probability waves or many worlds waves, which are not physical waves. The challenge is to formulate a Schrödinger equation which describes physical waves, that is to reach the objective of Schrödinger, which may possibly be done with something like realQM...
Ironically, Schrödinger's equation for just one electron is a physical wave equation, and so if anything can be explained by that equation it is the single electron double slit experiment and its mystery then evaporates...
PS The fact that putting a detector at one of the slits destroys the interference pattern, is also understandable with the electron as wave, since a detector may affect a wave and thus may destroy the subtle interference behind the pattern.