content: Ha, if they photographed that experiment their eyes would pop out of their heads (and not for reasons of double entendre).  My understanding is that light can be described as the propagation of a changing magnetic and electric fields (Maxwell's Equations). The maximum momentum that light can transfer occurs at the inflection points - where the two orthoganal propagating waves intersect, their forces are also at their strongest. This means that when scattering happens, it's going to look sinoidal - wavelike.  But really what we see is the result of two different waves having the possibility to be deformed, either from the influence by a magnetic field or an electric field.  What I think they would see is a clearer picture of how two orthoganal waves behave when they collide with the edges of the openings and with the interior parallel surfaces of the channel.  Remember, the slit/hole has a non-zero depth and none of its surfaces are going to perfectly flat, as that's a virtual impossibility at the sub-atomic level! These facts are undescribed / completely unaccounted for in all the experiments I have found!  The periodic nature of those two waves means that they sometimes collide fully (and thus don't continue) and other times they only glancingly collide, giving rise to the "strange" diffraction patterns we see.  I would expect to see vastly patterns depending on the depth of the channels.  I would also expect to see different patterns based on the material used to occlude the light.  I would also expect to see different patterns when the material used is at different temperatures.  If anyone has a source for research done in this area, please link me. What I'm trying to say is that light is always a wave, but it can transfer momentum at certain points along its propagation.  Saying it has a "particle-like" nature is a bit weird when it's just transmitting momentum. Haha, just kidding, you can split a beam of light and you will get an electron and antielectron / positron.  But again, just kidding because these two "particles" are also just weirdly behaving waves. I think this paper is describing what I'm talking about with regards to the sinoidal collisions (it's very, very recent), but I don't have a subscription: http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=2441838