2
" In 771, a traveller arrived in the city [Baghdad] with a copy of a work of Hindu astronomy called the Siddhanta (The Opening of the Universe), by the Indian mathematician Brahmagupta (598-668). Unlike Euclid, Brahmagupta did not set out his mathematical propositions clearly with proofs, but obscured them (as was traditional in Indian mathematics) under a veil of poetry -- beautiful, but extremely difficult to unravel. Al-Mansur gave his court astrologer, al-Fazari, the Herculean task of translating the Siddhanta, which introduced Baghdad to the concept of 'positional notation' -- the way we write numbers to this day, using the digits 1 to 9, in columns of units, tens, hundreds and so on. The possibilities that this system opened up were limitless; when it was eventually adopted, it transformed the entire discipline of mathematics by allowing calculations that would have been impossible with the old Roman-numeral system. Positional notation was already known in Syria and had been admired by Severus Sebokht, who wrote about the 'nine sings' of Indian mathematicians in 662. "
― , The Map of Knowledge: How Classical Ideas Were Lost and Found: A History in Seven Cities
5
" Además de su extraordinaria voz, Ziryab llevó a Córdoba todas las maravillas y la sofisticación de la corte abasí; se le atribuye haber hecho entrar a al-Ándalus en el siglo IX, por así decirlo, al introducir en el país una enorme variedad de innovaciones en el campo del refinamiento, como la pasta dentífrica, las comidas compuestas de distintos platos, los espárragos, los cubiertos, los manteles, nuevos peinados y atuendos, así como nuevos instrumentos y estilos musicales. "
― , The Map of Knowledge: How Classical Ideas Were Lost and Found: A History in Seven Cities