Evaluating scientific explanations
what evidence contradicts the theory that moving two-ton
stones was physically impossible for the egyptians, and
must have been done using alien technology?

The theory of wet sand contradicts this theory.

Explanation:

There was a myth regarding the moving of huge pyramid stones by the Egyptians, that they used some unknown technology to do that. But recent research nullified this theory by presenting a contradictory theory in this matter. It says that Egyptians might have wet the sand ahead of a contraption that has been built for pulling weighty objects.

The investigation of the physicists of Amsterdam University proved that damp sand in front of the device decreases the sled friction and makes it easier to move. This discovery was supported by the evidence gathered from ancient Egyptian paintings.