Hipparchus

thumb|A portrait of Hipparchus of Nicaea from "The School of Athens" by Raphael. thumb|Hipparchus Hipparchus of Nicaea (c. 190 – c. 120 BC) was a Greek astronomer, geographer, and mathematician. He is considered the founder of trigonometry but is most famous for his incidental discovery of precession of the equinoxes. Quotes I have composed a book on the length of the year in which I show that the tropical year contains 365 days plus a fraction of a day which is not exactly 1/4 days as the mathematicians-astronomers suppose, but which is less than 1/4 by about 1/300. Hipparchus from Ptolemy, Almagest Never deceive a friend External links Category:Astronomers from Greece Category:Mathematicians from Greece Category:Inventors Category:Non-fiction authors Category:BCE births Category:BCE deaths Category:Geographers from Greece