RC Macaulay wrote:
Back to Egyptian pyramids.. The scope of teh work and technology required leaves me wondering how much of ancient history is missing.. we actually know or understand so little. Take the library of Alexandria in Egypt that was sacked and burned in later BC. The Greeks recorded the library contained 70,000 years of records. The Egyptians scoffed at Grecian works and architecture...
Well, sure. For all their fancy buildings the Greeks never learned how to make a sensible doorframe, nor how to build a ceiling that wouldn't fall in. Flat stones on the tops of doorways and planks to hold up the roof were about as far as they ever got. But flat stones supported at the ends aren't reliable; stone isn't strong in tension and if you just wait long enough flat stone tops on doorframes will crack and fall.
Note that none of the (well-known) Greek ruins have roofs, and the doorways are nearly all open to the sky.
Now, when we look at the Romans things are very different indeed -- domed roofs made of concrete were one of their specialties, with the mix of concrete graded to match the thickness as they went from the bottom of the dome to the top.
