One of the problems with attempting to discuss the issue of Foreknowledge as it relates to Free Will is that the term itself prejudices the discussion, bending it in a certain argumentative direction that the use of different terms would show is not as inevitable as Calvinists insist.
Both Special and General Relativity assure us that not only space, but time also, are malleable changeable entities that are generated by the existence of matter. Being created entities, they are obviously unable to impose their limitiation on the Creator, since it is He who imposed those limitations on them. Since both change in complementary ways as a result of relative motion, gravity, and acceleration, we have to conclude that God is as equally a master of Time as He is of Space. That is, in addition to being Omnipresent, He must also be Omnitemporal. It is only because we are able to navigate space that we more readily accept His Omnipresence, in the same way that we having knowledge can picture Him having Omniscence, or our having power that we can picture Him being Omnipotent. In a complementary sense, it is our inablity to navigate time that renders it difficult for us to picture Him being Omnitemporal. This necessarily changes the terms of the debate concerning God’s foreknowledge and our freewill, most notably by demonstrating that the term “foreknowledge” is misleading, and thus inappropriate to use.
It is due to the inherent limitations of humanity’s mental and physical mismatch between being able to navigate space while totally unable to navigate time that I have to resort to thought experiments to overcome the inability to see beyond those limitations. For instance, it is incorrect, and quite insulting, to say that God knows of a specific event in a specific location by observing the effects of that event from a different location. Rather, it is more proper to say that He witnesses an event that happens anywhere because He is already there and present whereever it happened. The complementarity of space and time allows us to replace “where” with “when” in the previous two sentences. That is, it is incorrect, and quite insulting, to say that God knows of a specific event happening at a specific time by observing that event from an earlier time (foreknowledge). It is more proper to say that He witnesses an event that happens when it happens because He is already then and present when it happened. Omnitemporality and Omniscience enable God to say, with perfect honesty about any event occurring anywhere in the Universe and at any moment of time, “I distinctly remember being there when it happened”.
If this seems like time travel, consider the implications of God giving you the Zulu times and coordinates of the next five gamma ray bursters two weeks before each occurs, in response to which you spend the first week advertising the fact and the second enduring the ridicule of Dawkins and company until the burster appears on the sensors of multiple Gamma-Ray observatories at the time and in the direction predicted. Scientists would be compelled to admit that something unusual would be going on, since there was no way you could have observed the bursters two weeks before they saw them: The gamma rays that constitute the observation of the bursters travel at the speed of light, and it would be impossible for you to travel two light-weeks out, observe the gamma rays from the burster from that vantage point, and get back to earth two weeks before they arrive to advertise the fact, because that would require travelling faster than light. (Travelling out less than two light-weeks would be travelling out to a point where the gamma rays haven’t arrived yet to be observed.)
Obviously, it would be no difficulty for God to perform this prediction. However, there are three ways that God could do this. The first would use His Omnipresence: He would be next to you telling you of what He is simultaneously seeing from a point two light-weeks away from earth on the direct path of the rays from the burster to earth. The second would use His Omniscience to remember when and where the Gamma ray burster occurred (Him being present when it happened), and then waiting until two weeks before the gamma rays reach earth to tell you. The third would use His Omnitemporality to read to you the (Zulu) time and date off the LCD clock at the X-Ray observatory when the alarms sound two weeks later to signal the detection of the burster. Probably the majority of us would have thought of the second method immediately, and would grant the possibility of the first as a “logical extension” of Omnipresence. It is the third that we find the most “incredible,” but it is only so because we impose our inability to navigate time upon God, reducing the Creator to the limitations of the creature.
Thus, it is not possible to falsify what we would “call” God’s “foreknowledge” of our doing an action by doing something different because God’s knowledge of that action being performed at that time was acquired at the moment we ourselves performed the act and subsequently lost the ability to do something different. That is, freedom of choice is freedom to make a choice, not to undo that choice after it is actually made. (My thanks to SEA member Robert, whose entry “Outcomes, Foreknowledge, and Free Will” outlined the key concept that started the train of thought embodied in my original essay at my website here, from which I copied and expanded this article.)