How is it known that the Earth rotates? Describe how precise measurements of this rotation, particularly those involving eclipses, have demonstrated that the Earth is gradually slowing down.

Ancient Greek cosmology postulated Earth as the static centre of a Universe rotating around it, citing as evidence, the fact that the stars appear to move around the skies. This model held true from the time of Homer and Hesiod, through Aristotle, right into the 17th Century when Galileo and the invention of the telescope helped prove definitively that this was not the case. Philolaus (500BC) and Copernicus (AD1543) had both previously introduced alternative systems …

…Historical Eclipses and Earth's Rotation, Cambridge University Press *<Tab/>Stephenson F R (2003) Harold Jeffreys Lecture 2002, A&G, vol 44, Apr 2003 *<Tab/>Morrison L V (1985) The Day Time Stands Still, New Scientist, vol 106, 27 June 1985 *<Tab/>Mc Donnell K, Macquarie University, Sydney Australia and *<Tab/>Hughes C, Bidsten Observatory Birkenhead UK, http://www.newscientist.com/lastword/results.jsp?query=rotation