When does pyramid built?

 When were the pyramids built?

Let us now discuss the difficult question of when the pyramids were built. In the last section we will tentatively address the question of who were the builders.

Concerning the time of construction, there are some scholars, say Bauval and Gilbert (1994), who reject the standard dating at the fourth dynasty time,  and claim a very ancient age for the pyramids, dating them at about the Platonic time for Atlantis, say 9500 BC. They support their dating by certain stellar alignment. We do not discuss here their theory, where an important point is a supposed alignment of the three pyramids as the three central stars of the Orion constellation (Al Nitak, Al Nilam, Al Mintaka). We recall that a different, and more precise, alignement has recently been proposed by us, see Spedicato (2015), where the reference is to three volcanos in Mars, set between Mons Olympus and Valles Marineris; a reference to erupting volcanos would additionally explain the name pyramis, that in Greek means originally having the shape of a flame, a meaning that could not be understood in the standard framework. We propose a date of about 3450 BC, much earlier than theirs but older than the dates considered by academics,  on the following arguments