Lecture 18: The Apple and the Moon - Newtonian Gravity
What is Gravity? This lecture reviews the law of falling bodies first\ndescribed by Galileo, and then Newton's explanation in terms of his Law\nof Universal Gravitation. Gravity is a mutually attractive force that\nacts between any two massive bodies. Its strength is proportional to\nthe product of the two masses, and inversely proportional to the square\nof the distance between their centers. We then compare the fall of an\napple on the Earth to the orbit of the Moon, and show that the Moon is\nheld in its orbit by the same gravity that works on the surface of the\nEarth. In effect, the Moon is perpetually "falling" around the Earth.\nRecorded 2006 Oct 16 in 100 Stillman Hall on the Columbus campus of The\nOhio State University.