Originally posted by earth2
Has any one heard the theory that the Great pyramid was used as an Astronomical Observatory?

This seems to be the most logical explanation to me so far.

With the pyramid approximately half built (summit of the Grand gallery)with a truncated top they used the Grand Gallery to observe the stars, a meridian slot .The observer would have been able to watch the transit of each star as it passed. A reflecting pool at the bottom would have been used to note the exact time of its transit.
This theory also explains the notches cut along the Gallery ramp, 27 watchers used the notches for a bench.
This would have been a very accurate method of recording the heavens.