History of Eyeglasses and Sunglasses. The inventor of the first spectacle lenses is unknown. Roman tragedian Seneca (4 BC -65AD) is said to have used a glass globe of water as a magnifier to read ''all the books of Rome''. It's been reported that monks in the middle ages used glass spheres as magnifying glasses to read.
exists and is an alternate of . The Planet Venus has the slowest rotation rate because one day there is longer than the year on Venus or longer than its revolution around the sun. The Planet Venus has the slowest rotation rate because one day there is longer than the year on Venus or longer than its revolution around the sun.
When Voyager 2 visited Saturn in 1981, the probe measured the planet's rotation period at about 10 hours, 39 minutes. But when Cassini first arrived at the planet in the early 2000s, it determined Saturn spun once on its axis every 10 hours and 47 minutes, and those numbers changed each time Cassini took a look.