Transcript: Pythagoras was one of the most influential thinkers in history. This Greek philosopher and mathematician came up with the idea that numbers were the basis of everything. There is no written record, and nothing about Pythagoras survives in writing. He essentially ran a secret society of mathematicians, and later in his career his entire group was hounded by the authorities of Greece and had to leave the Greek mainland. In cosmology he believed that numbers were the basis of everything that happened in the celestial sphere. On Earth he derived things as important as the Pythagorean theorem. The statement, “A-squared plus B-squared equals C-squared,” is a fundamental statement not just of geometry but of algebra, and it’s also a statement of the geometry of space. The Pythagorean Theorem is only true in the space described by Euclidian mathematics. Pythagoras was impressed enough with his discovery of his theorem that he sacrificed a hundred oxen to the gods. Pythagoras discovered the rules of musical harmony by dividing a string and listening to the notes that emerged, and he actually believed in the harmony of the spheres, that sounds could be heard by enlightened people from the heavens due to its fundamental basis in number and harmony.