howdy, so, we are told in school that because of d=1/2a*t^2 and a=F/m that a will be constant, 9.8, g, no matter what the mass of the "falling" object so that the moon and earth would fall toward each other at 9.8 m/s/s just as a bowling ball toward the earth Why is there only one mass in the above acceleration equation but 2 in F=G(m1*m2)/R^2 ???? Based on the above assumption the earth falls toward the moon at 9.8 m/s/s but when you go to the moon, the value of a is not 9.8 m/s/s. If the above were totally true I could interchange either mass. Is d=1/2g*t^2 a huge approximation that neglects the gravity of small objects? Just wondering because i was reading the sample chapter of "The final theory" here: http://www.thefinaltheory.com/images/Final_Theory_--_Chapter_1.PDF and the claim on page 56 is that this constant acceleration of gravity is a big mystery of science. I wanted to tell him he is wrong, but then I started to doubt myself. Could someone please clear this up for me?