The builders of the pyramids knew astronomy very well. In the 1980s, the Belgian engineer and amateur Egyptologist Robert Beauval decided that, supposedly, the three largest pyramids of Giza are located exactly in accordance with the three bright stars in the "belt" of the constellation Orion (and even the sizes of the pyramids coincide in relation to the sizes of these stars ). And it is quite possible that somewhere under the sands other pyramids are "hiding", which are the rest of the stars of Orion on the earth's projection (most likely, badly destroyed). Why Orion? Because it was there, according to the ideas of the ancient Egyptians, that the souls of the dead pharaohs went.
Other scientists (in fact, pseudo-scientists) argue that the builders of the pyramids also had accurate knowledge about the structure of our planet - for example, about the length of its equator, about the approximate weight, about the length of the Earth's orbit and about the speed of its rotation (and even about the speed Sveta!). Allegedly, all these figures are incorporated in the proportions of the pyramids. Are you serious guys?