So maybe it should actually be called Khayyam's triangle. And just to get a sense of his poetry or a sense of the Rubaiyat in general, which I encourage you to look up and read, and this is at least Fitzgerald's translation of it. And that inverted bowl we call the sky, where under crawling cooped we live and die. Lift not thy hands to it for help, for it rolls impotently on as thou or I. So as you can imagine, the Islamic world, these empires between the 8th and 13th centuries, it was actually a very powerful bridge of human knowledge, taking knowledge from the Indians, the Chinese, the ancient Greeks, and providing a bridge during the Dark Ages in Europe. And to get a sense of that, we have some texts from some historians on that time period. This is some text from, this is some text from the historian Philip Hittie.