I added an update to my post on the seeming Islamic sundial in the Flight 93 memorial. I was able to resolve, or pretty much resolve, the uncertainty over whether the tower platform should be included in the gnomon height. I found a topo map of the crash site on TerraServer that shows that the sundial site slopes upwards from the tower towards where afternoon shadows land, and by just about exactly the height of the platform. Thus it seems that the proper gnomon height is just the tower, without the platform. (My graphics have been based on this assumption, but the site plan's topo map was not very clear.)
Alec Rawls To use the link below, you may need to cut and paste. http://errortheory.blogspot.com/2005/10/crescent-tower-is-islamic-prayer .html -
