Non-Euclidean geometry that are both perpendicular to a third line: Euclidean geometry, named after the Greek mathematician Euclid, includes some of the oldest known mathematics, and geometries that deviated from this were not widely accepted as legitimate until the 19th century. The debate that eventually led to the discovery of the non-Euclidean geometries began almost as soon as Euclid's work "Elements" was written. In the "Elements", Euclid began with a limited number of assumptions (23 definitions, five common notions, and five postulates) and sought to prove all the other results (propositions) in the work. The most notorious of the postulates is often
Tomb of Alexander the Great 4th or early 3rd century BC Alexander's body was transferred from the Memphis tomb to Alexandria for reburial (by Ptolemy Philadelphus in , according to Pausanias). Later Ptolemy Philopator placed Alexander's body in Alexandria's communal mausoleum. The mausoleum was called the Soma or Sema, which means "body" in Greek. By 274 BC Alexander was already entombed in Alexandria. The Tomb of Alexander became the focal point for the Ptolemaic cult of Alexander the Great. In 48 BC Alexander's tomb was visited by Caesar. To finance her war against Octavian, Cleopatra took gold from the tomb. Shortly after the death of