You have made a good point.

I saw a representation of an angle, and it looked to me like a horizon, but the picture could have been entertained without even contemplating the east-west horizon, so I am happy to forget that idea, as I mentioned in my last post.

The angle of the pole of the night sky, and arguably Alpha Draconis, was the most important angle, and the proposed representation in the east-west plane made me jump to the conclusion that the latitude north of the equator was seen as exactly equal to the angle of the pole of the night sky, which was not necessarily the case.

I think that the relationship with latitude may, however, have been understood to some degree, because the elevation of the pole star increases in the journey down the Nile from Upper Egypt to Lower Egypt until it is very close to 30 degrees at Dahshur.

Similarly, the angle of the sun at mid-day at the equinox was, of course, very close to 30 degrees at Dahshur, but decreases in the journey up the Nile, such that it remains the same as the angle of the pole star, but with respect to the vertical rather than the horizontal.

The geography of Egypt meant that AE would only have need a modest grasp of the world around them to come to the view that I proposed, and would not have needed a fully developed concept of latitude.

My picture in degrees would fit, even if AE did not divide the circle into degrees, but for it to fit so precisely would have required the circumference of a circle to be divided into a large number of divisions.

If someone else had raised this theory then my objection would have been that the round numbers and squaring the circle lead to a very precise angle, which would not have been the case unless that was the basis of the location. ie that AE decided to build at an odd location defined by an obscure geometric relationship.

It seems more likely that AE would have a chosen a location, and then determined how to represent that location geometrically, which could not have involved such regular geometry without an astonishing coincidence, and if this was the case then we would not be able to differentiate between coincidence and intention.

The exception to the rule is Giza, where regular geometry can define the position of the pole star at 30 degrees above the horizon (or 1/12 of the circumference of a circle), but the discovery of an angle of 30 degrees in some aspect of the plan at Giza has the uncertainty that it was not necessarily connected to the angle of the pole star (or pole of the night sky) because it is such regular angle.

Mark