Some years ago Dr Hawass wrote an interesting article entitled 'The Peak and Splendour of the Old Kingdom from the Fourth Dynasty to the end of the Sixth Dynasty' which I accessed in March 2005. His words stuck in my mind. I have just checked and the article is still on the web at [www.guardians.net]
I do not know what Dr Hawass meant by a profound knowledge of astronomy. Prior to my study of the Bent Pyramid I would have said that the ancient mind must have been fascinated by the cycles of the sun, moon and stars. And that it should have been possible to observe 309 lunar months in 25 calendar years of 365 days. It should, of course, have been possible to observe 40 solar years in 40 calendar years and one Egyptian week of 10 days. If the ancient Egyptians observed precession, and attempted to measure it, then I would say that an estimate within 1000 years of 25,800 years would have represented a very high standard of observational astronomy.
Let me make it clear that I do not think that the ancient Egyptians had some secret technology which has not yet been discovered. They could not have measured as precisely as modern astronomers without modern instruments. Perhaps they were not scientific in the modern sense of the word, and may have wanted to see the world in convenient round numbers. But I think careful observations are the basis of scientific enquiry. I would say that the determination of the annual solar cycle was a very important astronomical discovery in the history of the world.
From memory I read that the ancient Greeks measured precession at not less than one degree every 100 years, which was justified by the observations. It concerns me that it may have been impossible to have estimated precession as precisely as a period of 25,920 years without a bit of luck. I should make it clear that I am interested in what the ancient Egyptians may have discovered. I do not agree with mystical or extra terrestial theories which argue that the ancient Egyptians received knowledge from outside the boundary of science. And by science I mean what could have been discovered from ancient observations.
If it was ever accepted that the ancient Egyptians had discovered precession, then it would be seen as a great achievement, but to many not as great as the construction of the Bent Pyramid. I am not claiming anything more marvellous than is already apparent, just something different, as many have done before me.
All the other points you make are fair enough. I hope to reply to Graham next week unless our discussion continues.