I noticed something today on the way to work. Sun shafts seem to always point at the sun. On first glance, this is a no duh idea, but then I started thinking... why does the angle between these sun shafts vary so significantly? Wouldn't the sun have to be located in earths atmosphere to cast such dramatic angles?
Then I realized ohh duh, these shafts aren't perpendicular with the horizon, the slope they exist on is in three dimensions, and the ones that I can see from my perspective at least, are leaning away from me (toward the sun)... more specifically, these shafts are actually all parallel!
Then I started thinking more about the path of the light, and my brain started hurting again, as the shafts are most likely reflected/refracted bits of atmosphere/clouds that are luminated by holes in the clouds permitting light through in specific areas. More specifically however, the intensity of the light coming from these shafts is proportionally related to how much the light has to bend off its original course... meaning that looking in the sky, and you will see only light shafts around the sun... and not every where the clouds cast shadows.