We’ve all see shafts of light and shadow radiating away from the sun when it is low to the horizon. How often do we think about the fact that those radiating “rays” are not at all what they appear, and that it’s not even possible for them to be what they appear to be if you consider that the sun is not within our own atmosphere but is 93-million miles away? Years ago, someone told me that you could sometimes see those same shafts of light and shadow on the opposite horizon, and that was the first time it ever occurred to me that those “rays” are actually broad sheets of light and shadow (sheets turned on edge) coming straight at the viewer, and then continuing on in the opposite direction! Interestingly, I’ve seen some really smart, science-based people scoff at this idea, which shows just how convincing the illusion can be that the rays are actually shooting crosswise across the sky away from the sun. I looked up some info on this just now, and here’s a passage that appears in several online articles about this:
“Crepuscular rays are rays of sunlight that appear to radiate from the point in the sky where the sun is located. These rays, which stream through gaps in clouds (particularly stratocumulus) or between other objects, are columns of sunlit air separated by darker cloud-shadowed regions. Despite seeming to converge at a point, the rays are in fact near-parallel shafts of sunlight, and their apparent convergence is a perspective effect (similar, for example, to the way that parallel railway lines seem to converge at a point in the distance).”
So, when conditions are right, you actually CAN turn around and look the other way, and see those exact same shafts of light (sheets of light turned on edge) appearing to converge at a location which is exactly opposite the location of the sun. A couple weeks ago I just happened be out taking pictures when this phenomenon could clearly be seen. The setting sun in the west, surrounded by the typical rays, was slightly above the horizon, so the apparent point of convergence of these same rays in the eastern sky was just below the horizon. Pretty cool, I thought.