The Globe: How the Earth Became Round

This fascinating chronicle by historian Hannam (The Genesis of Science) traces how humanity’s understanding of Earth’s shape has changed over millennia. He notes that 6th-century BCE Babylonians believed Earth was “a disc girted by sea and mountains,” and that around 1000 BCE the Aryans of India believed the world rested on the back of a turtle or elephant. According to Hannam, Aristotle was the first person to figure out that Earth was a sphere, but he was “right for the wrong reasons,” believing that the planet was an accumulation of solid matter that “had fallen towards the centre of the universe.” The author examines the slow spread of Aristotle’s discovery, discussing how the popularity of astrology in India during the first centuries of the common era drove astronomers to study the Greek philosopher and his intellectual heirs, and how rabbi Judah ha-Nasi’s favorable remarks in the Talmud about Greek cosmology paved the way for Judaism’s abandonment of the Hebrew Bible’s assumption of a flat Earth. The trivia captivates (the prevailing view under China’s Han dynasty claimed “the sky was round and the Earth was square”), offering a globe-trotting tour of how a major scientific breakthrough made its way across the world. Readers will be enlightened. (Aug.)