Advanced Calculus
HIPPARCHUS (c 190 – c120 BC)
Hipparchus was a Greek astronomer, mathematician and geographer. Surprisingly little is known about his early life. He was most certainly born in Nicaea, Bithynia, (which is now known as Iznik in Turkey), around 190 BC. Most of what we do about him comes from the books of other scholars who came after him, such as Ptolemy and Strabo. It seems likely that Hipparchus studied in Alexandria but spent his later life in Rhodes. Strabo, another Greek geographer writing about eighty years after Hipparchus’ death, describes him as “one of the famous men of Bithynia”. The astronomer Claudius Ptolemy, who extended some of Hipparchus’ work about two hundred and fifty years later, admired his hard work and his quest for truth.
Hipparchus is recorded has being the first to make a catalogue of stars. He probably made his observations while living in Rhodes, from about 146 BC. He observed 850 stars and graded them according to their brightness. His brightness scale ranged from 1 (the brightest) to 6 (the dimmest). Interestingly enough, Hipparchus scale is still used today! The only difference is that he did not have the luxury of using a telescope. He could only see what we now call 6th magnitude stars (those that are just visible to the naked eye). From an observatory today we can see stars of the 22nd magnitude. Hipparchus also listed the stars in each constellation and noted their positions. Ptolemy continued his work and catalogued another 37 stars, bringing the total to 1080.
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As a mathematician, Hipparchus is credited with dividing a circle into 360° and being the first to use trigonometry. Using observations during the solar eclipse, probably in129 BC, he was able to work out the distance from the Earth to the Moon. The eclipse at Alexandria had been partial, four fifths of the sun had been covered, but at Syene it had been total. By measuring angles and applying distances between the two cities he was able to
Hipparchus was a Greek astronomer, mathematician and geographer. Surprisingly little is known about his early life. He was most certainly born in Nicaea, Bithynia, (which is now known as Iznik in Turkey), around 190 BC. Most of what we do about him comes from the books of other scholars who came after him, such as Ptolemy and Strabo. It seems likely that Hipparchus studied in Alexandria but spent his later life in Rhodes. Strabo, another Greek geographer writing about eighty years after Hipparchus’ death, describes him as “one of the famous men of Bithynia”. The astronomer Claudius Ptolemy, who extended some of Hipparchus’ work about two hundred and fifty years later, admired his hard work and his quest for truth.
Hipparchus is recorded has being the first to make a catalogue of stars. He probably made his observations while living in Rhodes, from about 146 BC. He observed 850 stars and graded them according to their brightness. His brightness scale ranged from 1 (the brightest) to 6 (the dimmest). Interestingly enough, Hipparchus scale is still used today! The only difference is that he did not have the luxury of using a telescope. He could only see what we now call 6th magnitude stars (those that are just visible to the naked eye). From an observatory today we can see stars of the 22nd magnitude. Hipparchus also listed the stars in each constellation and noted their positions. Ptolemy continued his work and catalogued another 37 stars, bringing the total to 1080.
Public Domain Image
As a mathematician, Hipparchus is credited with dividing a circle into 360° and being the first to use trigonometry. Using observations during the solar eclipse, probably in129 BC, he was able to work out the distance from the Earth to the Moon. The eclipse at Alexandria had been partial, four fifths of the sun had been covered, but at Syene it had been total. By measuring angles and applying distances between the two cities he was able to