Gravitation and the Force of Gravity
by Ron Kurtus (revised 2 September 2007)

Although many had previously studied the effect of gravitation, where objects seem to be attracted to the ground, it wasn't until Isaac Newton formulated the Theory of Universal Gravitation that the phenomenon could be explained and predicted. He defined gravity as a force that acts at a distance and attracts bodies of matter toward each other. Years later, Albert Einstein developed a completely different theory of gravitation in his Theory of Relativity, saying it was due to a curvature in space. Modern theories try to explain gravitation with gravity particles or waves.

Questions you may have include:

How did Newton discover gravity?
How do we experience gravity?
What is the influence of gravity in the Universe?
This lesson will answer those questions. There is a mini-quiz near the end of the lesson.
information from this web page
http://www.school-for-champions.com/science/gravity.htm