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 Archimedes
worked out the ratio of the length of a circle's
circumference to its radius (pi), discovered the
principle of buoyancy, explored the principle of
the lever, and devised numerous machines to help
defend his home town from invading Roman armies. |
 The Difference
Engine was conceived to calculate
and automatically print error-free mathematical
tables. It is so named because of the
mathematical principle upon which it is based,
the method of finite differences. |
 Rubik's
Cube was invented by a Hungarian
professor in 1974, as a mental exercise for his
students. The cubic puzzle quickly became a craze
in Hungary, then spread across Europe, and by
1980 was the top-selling toy in the United
States. |
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