Looking straight up through the 'caperture' reveals a small area of sky in which the sun and moon never appear; the angle is too great. However, looking through the aperture at an angle, that is, from the mound, brings both sun and moon into view. The rectangular patch of light cast by the aperture falls neatly across the eyes, and the sun can be GAZED UPON. This reveals its true nature; multicoloured, heaving boiling, dazzling but not damaging, and the Solar Corona can be discerned. I'm not sure whether sunspots can be seen or whether these are floaters in my eyes...but this is taking things a little far. Do not try this at home please, the optical dynamics of the process have to learnt before they can be attempted, otherwise eye damage might occur. I have been doing this for 20 years without damage to my eyes, but I know what I'm doing. My eyes are checked regularly and the opticians are astonished. Preliminary findings suggest that the caperture has, in 3 dimensions, the properties of a superellipse, or 'squircle', and this gives the physics of it optical properties that are also the subject of investigation.
After 12 years I know this structure pretty well but its full of surprises. The above only scratches the surface George, I'm glad to have engaged your interest.
We continue.
David Kane.
Something is not right. This message is just to keep things from messing up down the road