Heliocentrism before Copernicus

In his interesting review of P. C. Deshmukh’s Foundations of Classical Mechanics (Physics Today, December 2021, page 54 ), Robert Scott notes “that the 14th- to 16th-century Kerala school of astronomy and mathematics developed a heliocentric model of the solar system well before the Copernican revolution.” But I believe that for historical completeness, that statement should be supplemented by a note that about 1600 years earlier, in the third century BCE, Aristarchus of Samos proposed a heliocentric model in which Earth revolved about the Sun in a circular orbit with the Sun at the center. However, the writings in which he proposed that idea have been lost, and the only reference to his work from that century is by Archimedes in a letter to King Gelon of Syracuse. ¹

Aristarchus of Samos is regrettably skipped over in many popular accounts of early astronomy—for example, in Stephen Hawking’s well-known book A Brief History of Time: From the Big Bang to Black Holes (1988). Thus, years ago, when I was teaching an introductory course on the history and philosophy of science, I would ask the students whether they had heard of Copernicus, and everyone would raise their hand, but when I asked about Aristarchus of Samos, usually no hands went up. If I were still teaching, in addition to my usual covering of Aristarchus and Copernicus, I would teach about the Kerala school as well, thanks to Deshmukh’s book.