Article in need of improvement A substantial part of the article concerns a tunnel experiment as proposed by Galileo in his Dialogo The article would clearly benefit by having it pointed out that although it could be the experiment has as yet not been performed In its original form the idea is to have a tunnel dug through the Earth so that a test object cannonball can be dropped into it This is of course impossible But the same physical principles would be revealed by using laboratory sized massive bodies instead The experiment could be performed in an Earth based laboratory or in an orbiting satellite Articles that discuss these possibilities and present further reasons for doing the experiment can be found at and I have no experience contributing to Wiki but feel this issue is important enough to learn how to do so if this message is not sufficient to make it happen Please advise Thank you Richard Benish