Abu Ali al-Hasan Ibn al-Haytham
Abu Ali al-Hasan Ibn al-Haytham, named Alhazen, is a mathematician, physicist, and philosopher born in Basra, in ancient Iraq. He is the first physicist to understand why the moon and the sun appear larger when they are close to the horizon. He was also the first to understand that if we saw the Moon, it was because it was lit by the sun. Likewise, and unlike Ptolemy, he understands that our eyes do not send lights. If we see objects, it is because they are lit by light (from the sun) and that it is reflected towards our eyes.
Alhazen, a scientist yes, a madman no!
Legend has it that the Caliph asked him for help in building a huge dam on the Nile, a great river in Egypt. Deeming the work unfeasible, and out of fear of the Caliph’s anger, Alhazen pretended to be mad. He was forced to stay at home until the Caliph’s death.