What is really happening in the double-slit experiment, they say, and really wherever atomic particles are interacting with each other (that is to say, everywhere), is not that the two electrons are in two places at once. Instead, time is running both forward, from the electron leaving the wire, and backward, from its final location on the second screen
. Where time meets, running backwards and forwards, determines which slit the electron chooses. The future is affecting the past, all the time, on the quantum level.
(Sadly our brains don't work on the quantum level, although I really don't want to know what I will look like in another 10 years.)