Bell's Inequality, EPR Paradox
The paradox here is that two particles with linked physical properties are emitted from an interaction, do they or don't they have their properties internally fixed at the time the interaction occurred. Quantum theory says no. Two electrons are transmitted at 99.99 % of c. One travels one direction and the other travels 180 degrees away. After one year of travel, you check the x spin of one particle. The other you check the y spin. Since they are linked you have determined the x and y spin of both particles. This is not a possibility in quantum physics.
The flaw here is that the amount of time that passes or distance one travels is irrelevant. One can place the experiment in a moving frame of reference where the times seem like nanoseconds and the distances are only a meter apart. Which would fit it into a lab frame. The important thing to keep in mind is that distance and time duration are relative.
If one tries this experiment, one would find that once you try to confine the outcomes of the electrons to specific results the electron event doesn't occur. It's like trying to force an electron into a level of n= 1.33 in the hydrogen atom. The question becomes how does the particle know what or what not to do. That is the same question that has been around since QM. One can calculate the answer through probabilities. One still can't explain it unless one changes from ones personal understanding of time, space and determinacy to one based on physical principles.
If one assumes all interactions are determined through all time then the quantum effects are obvious. But then where is free will. If one assumes that you affect the past as easily as you affect the future then free will can be seen either to be completely gone if you are a pessimist or that you have greater control than one ever could imagine. By choosing to do something today, one affects all events into the past that led up to that decision.
A thought experiment: You set up a special pane of glass where light of a certain wavelength can not be transmitted, absorbed or reflected. You place it outside at night. The light from stars thousands of light years away and galaxies millions of light years away can not touch the glass. One proves light hasn't been absorbed by checking for a caloric rise in temperature. One proves light hasn't passed through or reflected by placing sensors behind and in front of the glass checking for stray photons. None are present. Where did the light go? It went no where, it doesn't exist. The stars billions of years ago never sent a photon along the trajectory that would encounter the glass. That is a consequence of Bell's theorem.