  :::If the linear momentum argument itself is nonsense, then this means that the concept of which way is also nonsense.  Afshar appears to be highlighting a paradox.  The paradox appears clear, and the only argument being used against this view is a logical one that apparently proves that which-way information is not retained.  In fact this counter view is just one side of the paradox.  On the other hand we have those who use their eyes and see that the photons appear to come from one slit or the other.  It is not nescessary for Afhsar to prove that the target hit corresponds to the hole the photon went through.  We all can see that is impossible.  That's the nature of paradox.  If the target hit is no indicator of which hole the photon went through, then just what is it that it indicates?  At what point does the photon stop being a wave and start being a particle? At the slits? At the wires?  In the lens?  It seesm quite clear to me that the only way to resolve this is to say that the photon exists as a probability field until it is measured.  In this way, there is no which-way because during the time from emission to detection, the photon does not exist as a particle, but as a probability function.  The only time that we can know where the photon actually is, is at the moment of measurement, at which point it ceases to exist.  Now there is no paradox, and no need for the principle of complementarity either.  