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History

The Scientific Contributions of Al-Ḥasan Ibn al-Haytham

Quick fact

Ibn al-Haytham wrote roughly 200 works, and his Book of Optics was so influential that its Latin translation shaped Western science into the 1600s. The image formed in a camera obscura is one of his direct experimental demonstrations.

Why this is interesting

You can see because light enters your eyes—but for almost a thousand years, many scholars believed the opposite: that your eyes reached out to touch the world. One 11th-century scientist changed that by insisting on proof.