I counted every twin prime under ten million. Hardy and Littlewood's 1923 guess landed within 0.3%.

Part 73 of Forgotten Theories, a series re-testing old scientific claims with modern tools. Find the rest under the #forgotten-theories tag. Twin primes are pairs of primes two apart: (3, 5), (5, 7), (11, 13), (17, 19), and on it goes. They get rare...