Born in England in 1214, Bacon originally trained in the Aristotelian sciences (geometry, arithmetic, music, and astronomy) at the University of Paris. His interest in more empirical sciences because later while studying the work of Grosseteste at Oxford, eventually applying geometry to optics and opening the way for more than observational science, for as Bacon said, “Mathematics is the door and the key to the sciences”. In 1257, he joined the Franciscans (Order of Friars Minor) but continued his work, writing Communia naturalium (General Principles of Natural Philosophy) and the Communia mathematica (General Principles of Mathematical Science), of which only parts were published. Among other things, he believed that the earth was round, and he estimated the distance to the nearest stars as 130 million miles. Bacon died in 1294, having been imprisoned by his fellow Fransicans but is known today as “doctor mirabilis”.