Three thousand years ago, in Ancient Egypt, people generally believed that the sun god Ra rose from the darkness each day and rode across the sky. Observations – by sailors, for example, who could watch mountains slowly sinking below the horizon as they sailed from shore – gradually disproved that notion.
However, for another 2,000 years it was still mostly agreed that the Earth was at the center of the universe and that all heavenly bodies revolved around it. Indeed, it could be quite dangerous to suggest otherwise. … Continue reading The Scala Naturae: Alive and Well in Modern Times