PolyHedral
Superabacus Mystic
The reaction of anyone can be predicted with arbitrarily high accuracy if one has enough data and a sufficiently powerful theory of mind. This idea follows from the theories of computer science and nothing is known that prevents it, only the difficulty of amassing enough data. How does one have free will if any sufficiently powerful intelligence can predict the will as accurately as it wants to? This intelligence need not be divine, or in any way disconnected from the universe.
Impossible, assuming a nigh- or entirely omniscient God. The question "What will I do in 10 seconds time?" is perfectly answerable, and it is entirely reasonable to think that God should have an answer to it.Would you like to question God?