Einstein, like Newton, assumed that light particles follow a fixed path from source to screen, so where it hits should be predictable, but it isn’t exactly so. Photons shot in the same way at a screen don’t all hit at the same point. Quantum theory explains this by saying that each photon hits the screen at a random point, chosen from the possibilities. Einstein concluded that there were two options: either quantum theory was wrong or there were hidden physical causes:
“This is the fundamental problem: either quantum mechanics is incomplete and needs to be completed by a theory of hidden quantities, or it is complete and then the collapse of the wave function must be made physically plausible. This dilemma has not been solved until today, but on the contrary has become more and more critical.” (Audretsch, 2004), p73.
This problem, which Einstein raised and Bohr ignored, still haunts physics today. All attempts to find physical variables that explain quantum randomness have failed, as have all attempts to show that quantum theory is incomplete. The problem then is that quantum theory works perfectly but it allows random events that have no physical explanation to this day.
What then is the resolution? Both theories, that quantum theory is incomplete or that it is physical, have led nowhere, so the answer must lie elsewhere. Materialism assumes that quantum theory is either incomplete or physical, but if it is wrong, quantum theory could be true and not physical. We know that quantum theory always works, and we know that it can’t be physical, so perhaps both are true. We then can’t find hidden variables to explain randomness because there are none, and we can’t find a fault in quantum theory because there is none. If quantum events create physical events, as quantum theory says, then randomness could arise from outside the physical domain.
For example, the laws of Minecraft don’t explain how its blocks exist, nor do the laws of chess say how its pieces exist, because that is outside their domain. A created scenario can never completely explain itself, so perhaps physical laws can’t explain randomness for the same reason. If I turn off a game, or tip over a chess board, it is an event outside the game domain. Likewise, randomness in our world could come from quantum events that occur outside the physical domain, but what could they be?