Here I'm playing around a polarized light. Sunlight is unpolarized, so it doesn't really matter what angle. I use a polarizing filter. If two filters, and they're polarized in the same direction, then essentially nothing too interesting happens. If the polarizers cross, then essentially light making it through one filter is horizontally polarized. Then the next filter only lets through the light that's vertically polarized, so cumulatively nothing makes it through. This is used to have adjustable filters in photography fairly often. Now something really interesting starts to happen, and in fact a quantum effect begins to kick in if I ask three questions. So surprisingly, the answer I get depends on the order that I ask the questions. So if I have a horizontally, diagonally, and then vertically polarized, I get a different answer than if I ask horizontal vertical or horizontal vertical vertical. So in between, I actually get a lot more light transmission than you'd expect. And this is an angular dependent sort of transmission. So it has to be between the asking the horizontal and asking the vertical question that I ask this diagonal question. And this is really a quantum effect. So if I ask the photons the same questions in a different order, I actually get a different answer, which seems a little disturbing to me.