Heliocentrism is, of course, the astronomical theory that the Earth revolves around the sun, as opposed to the other way around. It is often accredited to Nicolaus Copernicus, since he first laid out the hypothesis in detail in his book De revolutionibus in the 16th century. However, the idea was first proposed by the Greek astronomer and mathematician Aristarchus of Samos, way back in the 3rd century BCE! His writings have unfortunately been lost, but Aristarchus’ contemporary Archimedes gave him credit for it in his writings the very same century. I suppose this just illustrates how important it is to have a good publisher. Regardless, if this question is asked at trivia night, the answer “Copernicus” is probably what they’re looking for. Click here to browse through RiverShare’s books and media about our solar system.