I am relatively new to QM and so have a couple of basic questions for you all. I understand that the double slit experiment creates an ‘interference pattern’. What bothers me, is that it seems like an assumption to me, that the pattern created could *only* have been made by two waves interfering. Is it proven, or is it just an assumption? Has there been any other research that someone could kindly point me to, that attempts to (I imagine unsuccessfully) look for other ways to create such a pattern? Obviously there has been a lot of work done based upon this assumption, and therefore I believe a lot of work should be done to prove the assumption that it must be wave based. I could imagine a similar pattern being created by a particle bouncing repeatedly between the double slit wall and the back wall. Has anyone done the experiment and also placed a photographic plate (or whatever it is that picks up where they arrive)…on the back side of the double slit wall? It will probably be a waste of time, but it probably needs to be tried once doesn’t it? I have imagined doing a similar experiment with chalk covered tennis balls, they would bounce and I think create a similar pattern....particularly as they would always arrive on the back wall on a bit of an angle. I imagine there could be a number of ways that particles could build up such a pattern. Particularly if they have any magnetic qualities at all. Perhaps others with far more understanding of what these objects actually are have thought up other ideas? I also question the assumptions made about the measuring devices put in place to observe which slit the electron (or whatever was fired) went through. I can imagine that the choice of measuring device used so far, changed the behaviour of the electron …because of some, so far unknown, behavioural quality of the electron. I believe it is an assumption to say that *any* way of observing it will change its behaviour. We would just need to find another way of measuring it (which perhaps is not yet technically possible). It seems to me that all we know is that the way we have currently tried to observe it, has changed its behaviour, nothing more. Looking forward to being thoroughly flamed for my ignorance :-).