The path of the planets across the sky  makes no sense if you consider a "terracentric" (i.e.with Earth at the centre) system. This led ancient astronomers to name the planets thus. Planet means "wanderer". This was not a problem to them, why should a "star" not wander? Of course, once you accept a heliocentric system … Read more

Because standing on the Earth and looking up into the cosmos with only the naked eye and nothing else to aid our observation, leads one to believe that the earth is static and the heavens swirl around us, not that the earth rotates and revolves around the sun. For millennia, people actually believed the Earth … Read more