There are two radical views about what quantum mechanics is telling us about the motion of particles. The first is that, according to physicists such as John Wheeler, the particle does not come into existence until the act of 'observation' occurs. The second is that, according to the mathematical procedures developed by Richard Feynman and called 'sum over histories', the particle may travel any number of an infinite number of paths to get from point A to point B, perhaps even including a brief jaunt through all possible universes and all possible dimensions. There are also many other views in between!
How do we 'test' such proposals? How do we really determine just what it is that those crazy quantum particles are doing 'down there'? My guess is that we will never be able to do such a thing because any test is an act of 'observation' in itself, and so what we are testing for and expecting to see is what we will always observe.
Even Richard Feynman confessed that no one really understands quantum mechanics. The bizarre things is that we have mathematics which let us compute and predict outcomes with fantastic precision, yet we DO NOT YET UNDERSTAND IN A FUNDAMENTAL WAY why it is that the world works this way.