merrill@rex.DEC (11/15/84)
Jeff, Seems to me that at the point of convergence where the e-m fields BALANCE each other (they only "cancel" if you sum the values:-)) you detector (e.g. photosensitive film) sees no NET e-m field and hence registers nada. Moments later [at the bat cave] the fields collapse and the light continues on its merry way until completely absorbed or until the two beams again diverge. One exception would occur if the beams converged in a black hole! Rick