We have an illusion that consists of a hollow face of Einstein which seems to be looking at you whether you are looking at the front of it or the back. It’s very impressive. I use it to remind students (and myself) that there is a heck of a lot out there that we still don’t understand, even if we like to pretend otherwise.
The illusion can be purchased from grand-illusions.com, one of the very best sources for all types of illusions.
So when New-Scientist posted a video on how this was being used to test for schizophrenia, I thought perhaps it was time to check it out again (apparently people suffering from schizophrenia don’t notice the effect).
Think for Yourself 
RE: Photoelectric effect youtube video.
Using higher frequency EM radiation impacts higher energy levels to the metal plate resulting in reaching the threshold for electron emission. Surely, electron emission needs that higher energy level, not necessarily a particle vs a wave. A high-energy wave impact need not be a particle impact. Consider water waves arriving on a beach, or a loop send up a rope, or a blast from a big amplifier: waves can deliver a lesser or a bigger punch. I can understand the PE effect without resorting to a particle theory. Wave energy level conforms with causality (cause and effect): particle theory results in quantum theory which results in the “uncertainty principle” which defies causality.
Do you really think that the PE effect implies a particle nature of light?