But was the laser going through the 'gate or lending power to the super conductor of the 'gate itself? But we did see Sam shoot particles - I'm more and more convinced that momentum vectors are at play here.
(and, hm, radio waves (at least certain frequencies) can pass both directions where matter can't. I wonder what else can go both ways?)

Acting like a thin membrane makes sense to me - calculate purposeful impact versus Brownian motion - though then more would get through on a windy day? And temperature wasn't about differences, was it? But more just a by-product of the re-animation process?

I'm kinda glad they conserve momentum :)