Ptolemy or optical factors and those caused by judgmental factors. He offered an obscure explanation of the sun or moon illusion (the enlarged apparent size on the horizon) based on the difficulty of looking upwards. There are several characters or items named after Ptolemy, including: [[File:Ptolemaeus - Quadripartitum, 1622 - 4658973.tif|thumb|"Quadripartitum", 1622]] [[Category:Ptolemy| ]] [[Category:100 births]] [[Category:170 deaths]] [[Category:1st-century Romans]] [[Category:2nd-century Romans]] [[Category:2nd-century philosophers]] [[Category:2nd-century poets]] [[Category:Egyptian calendar]] [[Category:Ancient Greek astrologers]] [[Category:Ancient Greek astronomers]] [[Category:Ancient Greek mathematicians]] [[Category:Ancient Greek music theorists]] [[Category:Astrological writers]] [[Category:Claudii]] [[Category:Egyptian astronomers]] [[Category:Egyptian mathematicians]] [[Category:Epigrammatists of the Greek Anthology]] [[Category:2nd-century people of Roman Egypt]] [[Category:Ancient Greek geographers]]
Ptolemy Keraunos Ptolemy Keraunos Ptolemy Keraunos (, after 321 BC – 279 BC) was the King of Macedon from 281 BC to 279 BC. His epithet "Keraunos" is Greek for "Thunder" or "Thunderbolt". Ptolemy was the eldest son of Ptolemy I Soter, Pharaoh of Egypt, and his first wife Eurydice, daughter of the regent Antipater. After Keraunos' younger half-brother, also called Ptolemy, was named heir apparent and, in 282 BC, ascended to the throne as Ptolemy II, he had to leave Egypt, being a potential rival for the throne. He arrived at the court of Lysimachus, the king of Thrace and Macedon,