A cikin karni na 6 BC, Anaximander ya ba da shawarar ilimin sararin samaniya tare da Duniya da aka siffanta kamar sashin ginshiƙi (silinda), wanda aka riƙe a sama a tsakiyar komai. Rana, Wata, da taurari ramuka ne a cikin ƙafafun da ba a gani da ke kewaye da Duniya; ta hanyar ramuka, mutane za su iya ganin wuta da aka ɓoye. A daidai wannan lokacin, Pythagoras ya yi tunanin cewa Duniya ta zama ƙwallo (bisa ga lura da eclipses), amma ba a cibiyar ba; sun yi imani cewa tana motsawa a kusa da wuta marar ganuwa. Daga baya an haɗa waɗannan ra'ayoyin, don haka yawancin Helenawa masu ilimi daga ƙarni na 4 BC a kan tunanin cewa Duniya ta kasance ƙwallo a tsakiyar sararin samaniya.
Plato