Why Do People Believe the Earth Is Flat?

A flat Earth believer spent $20,000 on a laser gyroscope to prove the Earth stands still. It measured 15 degrees every hour, exactly the Earth's spin. He didn't change his mind. So why do people believe the Earth is flat? And how can you check it yourself? Ships that sink hull-first, a 2,000-year-old measurement with a shadow, the round shadow on the Moon, why gravity makes planets into balls, and the psychology of who we trust. ⏱ Chapters 0:00 The $20,000 gyroscope 0:35 Watch the ships 1:07 A pillar and a shadow (Eratosthenes) 1:52 The round shadow 2:31 Why big things are round 3:01 Why believe it anyway? 3:51 Test it yourself 📚 Sources • Behind the Curve (2018), documentary: the gyroscope and light experiments • Eratosthenes, c. 240 BC, as reported by Cleomedes • Aristotle, On the Heavens, c. 350 BC • Sacrobosco, De sphaera (c. 1230) · J. B. Russell, Inventing the Flat Earth (1991) • YouGov (2018), 8,215 US adults • Asheley Landrum, Texas Tech, AAAS 2019: flat Earth conference interviews • NASA planetary fact sheets · Coastlines: Natural Earth Cross-sections exaggerate curvature so you can see it; the ship's sinking in the telephoto shot uses Earth's real radius. Narration: AI voice. Animation: Why Guy. 🔔 Subscribe for a new "why" every day. #flatearth #science #whyguy