Backward Causation and Nonlocality in Quantum Mechanics. William R. Wharton, Wheaton College, Wheaton, IL 60187. (Paper to be presented at 3:30 pm on Oct. 29, 1999 at the ISAAPT fall meeting at Augustana College.)
Continuation of the Abstract:
Although the temporal and causal ordering of the universe tend to be similar, it is this similarity which has lead to a great confusion of these two concepts. To accurately discuss backward causation, the distinction between these two orderings must be crystal clear. An analogy can help with this distinction. Consider a straight river with flowing water. The physical position along the riverbank represents time, with the increasing time direction downstream. The flow of the water represents the casual direction. These two directions are generally the same -- viewed on a large scale. But now suppose there are many small barriers in the river, each of which partially blocks the flow of water. Suppose also that events downstream of the barriers can cause turbulence leading to eddy currents behind the barriers. The region of the eddy currents, behind these barriers, will exhibit "backward causation"; the flow of water (causality) will be reversed with respect to the riverbank (time). The eddy currents are affected by both the barrier (at an earlier time) and the events downstream at a later time, and the eddy currents flow both upstream (backward causation) and downstream (forward causation). In actuality the backward causation and forward causation may take the same path. Therefore the analogy requires two types of fluids moving through each other in opposite directions.