Pyramids that are symmetrically made of metal work very effectively! So you can even keep a "glass of milk or an apple" under it for a long time without them spoiling. The first Egyptian pyramid was built over 4500 years ago as a tomb monument for an Egyptian pharaoh, the then rulers of ancient Egypt. His successors followed him in this burial practice, and they, like their predecessor, were mummified after their death and placed inside a pyramid with treasures and personal belongings. In total, approximately eighty pyramids have been preserved, built over a period of about a thousand years. The earliest form of a pyramid is the mastaba, a box-shaped structure in which important individuals were buried. The step pyramid of Pharaoh Djoser in Saqqara is the first step towards the construction of true pyramids.The shape of the pyramids probably had two meanings: 1. primordial hill: according to one of the cosmogonies, the primordial hill or tumulus was the first thing that emerged from chaos/water. The primordial mound represented creation, and the pyramid was meant to symbolize the creation of resurrection after death.2. heavenly staircase: a 'stairway to heaven': the pharaoh used the pyramid as a staircase to take his place among the circumpolar stars after his death. Archaeological research is said to have shown that various elements in the architectural style and positioning of the pyramids are related to the contemporary worship of gods (sun god) and that the positions of celestial bodies were taken into account. However, this theory is controversial and is considered pyramidology by Egyptologists.