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>The Greek astronomer Eratosthenes (who lived circa 276 to 194 B.C.) used a sexagesimal system to divide a circle into 60 parts in order to devise an early geog
by fjcaetano 13y ago
>The Greek astronomer Eratosthenes (who lived circa 276 to 194 B.C.) used a sexagesimal system to divide a circle into 60 parts in order to devise an early geographic system of latitude, with the horizontal lines running through well-known places on the earth at the time. A century later, Hipparchus normalized the lines of latitude, making them parallel and obedient to the earth's geometry. He also devised a system of longitude lines that encompassed 360 degrees and that ran north to south, from pole to pole. In his treatise Almagest (circa A.D. 150), Claudius Ptolemy explained and expanded on Hipparchus' work by subdividing each of the 360 degrees of latitude and longitude into smaller segments. Each degree was divided into 60 parts, each of which was again subdivided into 60 smaller parts. The first division, partes minutae primae, or first minute, became known simply as the "minute." The second segmentation, partes minutae secundae, or "second minute," became known as the second.
This makes no sense. For this to be true, it implies that the ancient Greek already had knowledge that the Earth is round, 1600 years before Galileo.
- vmind 13y agoIt was theorised/known the Earth was round a lot earlier than Galileo: http://en.wikipedia.org/wiki/Spherical_Earth http://en.wikipedia.org/wiki/Spherical_Earth
- minikites 13y agoUh, what? They knew the earth was a sphere: https://en.wikipedia.org/wiki/Eratosthenes#Measurement_of_the_Earth.27s_circumference https://en.wikipedia.org/wiki/Eratosthenes#Measurement_of_th...
- njharman 13y agoThe ancient greeks, among others, had that knowledge. What makes no sense is the perpetuation of the myth that spherical earth is "new" concept. The concept of a spherical Earth dates back to ancient Greek philosophy from around the 6th century BC -- http://en.wikipedia.org/wiki/Spherical_Earth http://en.wikipedia.org/wiki/Spherical_Earth http://scienceblogs.com/startswithabang/2011/09/21/who-discovered-the-earth-is-ro/ http://scienceblogs.com/startswithabang/2011/09/21/who-disco...
- sanoli 13y agoThey did. http://en.wikipedia.org/wiki/Spherical_Earth http://en.wikipedia.org/wiki/Spherical_Earth
- zb 13y agoFirst of all, Columbus rediscovered America a good century before Galileo. Secondly, the idea that people believed in a flat earth before Columbus is entirely a 19th Century conceit: https://en.wikipedia.org/wiki/Christopher_Columbus#Geographical_considerations https://en.wikipedia.org/wiki/Christopher_Columbus#Geographi... In fact, the fact that the earth is (essentially) spherical was well-known to basically everybody since ancient times. For example, any sailor could have told you that when approaching land, the tops of mountains appear first over the horizon.
- dragonwriter 13y ago> First of all, Columbus rediscovered America a good century before Galileo. Well, "encountered" would probably be more accurate. Discovery -- even rediscovery -- requires recognition, and Columbus insisted he had reached the East Indies.