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Established 15,000 B.C. |
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Volume 10, circa September 130 A.D.
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| Ptolomy of Alexandria rediscovers the phenomenon of persistence of vision. (Probably because he had a bad blinking problem.) Persistence of vision is a visual phenomenon that is responsible for the apparent continuity of rapidly presented images, as in film or television, consisting of a breif retinal retention of one image so that it is overlapped by the next and the brain interprets it as being continious rather than separate and jarring. In film, the standard time frame per image is 24 frames per second. This means, that when 24 frames or separate images are presented to the eye, their differences in movement are perceived as smooth. Anything less than this creates a "flickering image". Hence, traditional, film animation is drawn and timed out at 24 frames per second. Video is 30 frames per second. |
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| Ptolemy (aka Claudius Ptolemaeus, Ptolomaeus, Klaudios Ptolemaios, Ptolemeus, and "that weird guy upstairs") lived in Alexandria (in Egypt) from approx. 87 -150 AD. Very little is known about his personal life (the image above is just an artist's rendition) He was an astronomer, mathemetician and geographer. He codified the Greek geocentric view of the universe, and rationalized the apparent motions of the planets as they were known in his time. |
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Ptolemy synthesized and extended Hipparchus's system to explain his geocentric theory of the solar system. Ptolemy's system involved at least 80 epicycles to explain the motions of the Sun, the Moon, and the five planets known in his time. He believed the planets and sun to orbit the Earth in the order Mercury, Venus, Sun, Mars, Jupiter, Saturn . This system became known as the Ptolemaic system. It predicts the positions of the planets accurately enough for naked-eye observations It is doubtful that Ptolemy actually believed in the reality of his system. He may have thought of it only as a method of calculating positions. In addition to his well known works in astronomy, Ptolemy was very important in the history of geography and cartography. Ptolemy of course knew that the Earth is a sphere. Ptolemy's is the first known projection of the sphere onto a plane. His Geography remained the principal work on the subject until the time of Columbus. |
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| Titus Lucretius Carus - ( 98 - 55 BC ) 'De Rerum Natura' - Book 4 pp. 768 - First reference to persistence of vision ..."This ( perception c.f. movement ) is to be explained in the following way; that when the first image passes off, and a second is afterwards produced in another position, the former then seems to have changed its gesture" also from another source... Titus Lucretius Carus, a Roman poet and philosopher, describes frame sequential animation almost two thousand years before the advent of motion pictures. | |||||||||||
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