Leonardo da Vinci compiled the Codex Leicester. It was named after the Earl of Leicester, who purchased it in 1717. In 1980, it was purchased by Armand Hammer, becoming the Codex Hammer. Finally, in 1994, Bill Gates purchased it and retitled it to its original name: Codex Leicester. It comprises 72 densely written pages, with very long passages and 360 drawings on geology, astronomy, and fluid dynamics. On one section of the page, he wrote: “The sun does not move” in large letters (he usually wrote very small). This was decades before Copernicus or Galileo, but Leonardo leaves us in the dark as to how he reached this conclusion. He also goes on to describe how the oceans do not fall from the Earth due to gravity, and that the Moon does not emit its own light but reflects solar light: “And anyone standing on the Moon would see the Earth illuminated in the same way that we see the Moon illuminated.” He even explains why the sky is blue: it’s not its true color but is caused by humidity in the air, which in tiny atomic particles captures sunlight and re-emits it as blue. Finally, after climbing Monte Rosa, he realizes that the sky up there is indeed darker because there is less air separating us from darkness.
