Of course we still don't know every detail about how megalithic cultures put together every stone of every monument. However, archaeologists have learned enough in the last twenty years to safely put to rest any speculation about space aliens or forgotten "advanced" technological secrets. The ancients no doubt had a lot of technologies we've forgotten -- not because of the fall of some "golden age" -- but because we've found other (usually better) ways to accomplish the same tasks. These ancient technologies weren't magic, they were just things we don't think about in our world; basic things that would make us say "how clever -- I never would have thought that would work!"
A quick glance at a book on historical woodworking techniques will reveal just how much we've forgotten in the last 200 years (let alone 4000 years). A weekend spent learning historical woodworking techniques will given one a HUGE appreciation for the skill, inventiveness, and patience of one's grandparents. But when it comes time to frame a house, I'll take a laser-aligned compound miter saw over an axe any day. My grandad was one sharp guy, but he was no more a demi-god than I am.
In the past decade, Egyptologists in particular have made huge leaps of knowledge. They can now circumscribe the human and technological limitations which would have obtained at the time the pyramids were build. They haven't fleshed out the details, but they're starting to know how many workers were involved, how much time it took, how much the workers ate, etc. They can say which ideas would and would not have worked, and do further research to test specific hypotheses. And nothing found so far points to magic or advanced technology; just a bunch of people about as smart as us, working really hard and making the best with what they had.
Ironically enough, a lot of the recent advances in archaeology have come from people who were initially attracted to field through pseudo-archeology in the 60's and 70's. Along the way, as they became students and grad-students, they learned that the truth was far more interesting.
-Neil
p.s. To EF: They couldn't have used the spaceship, Mummy hid the keys!
[ July 20, 2003, 07:42 PM: Message edited by: NeilUnreal ]