Gravitons and Push Gravity question.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by north</i>
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my thinking is that more the mass the more momentum therefore harder to slow down. i have always thought that Galileo's experiment was not high enough to prove that no matter the mass they fall at the same rate. for instance i have a hard time thinking that an object with the weight of a feather but not aerodynamicly disadvantaged and no atmospheric turbulence, would drop from 50,000 ft at the same rate as an plane. therefore the more mass the faster it would fall depending on the height, masses of objects to be compared and turbulance of air.
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It seems to me that if you take a BB and a cannon ball and drop them, what is happening is that each molecule inside the BB and the cannon ball are reacting to gravity in the same way and fall at the same rate. What does it matter if all the molecules of the cannon ball are stuck together? Suppose we separate all the molecules of the cannon ball into BB sized objects. They will all fall at the same rate, whether they are stuck together or not. Surely you wouldn’t say that 10,000 BBs glued together would fall faster than 10,000 BBs not glued together?

The two models being kicked around are like a lot of other models in that they cannot exist in the real world but are of use to see how things really work. Anyway, the main point is gravity effects are a lot different when the mass is not assumed to be positioned at the center of mass. What I want to determine is weather or not these models obay the R^3/T^2 law or not? It seems to me the acceleration of gravity is greater at the surface of a sphere than it is inside the hollow model and the same should be true for the solid sphere with a hole through it. And yet we seem to be saying the acceleration increases as we near the center of mass. There seems to be two things going on that oppose each other in these models.

Jim, didn’t Newton publish his opinion about a hollow sphere in the Principia? I think he said that a small mass inside a hollow sphere would just float around but not be attracted to the sides of the sphere.

Hi David, I don't know what Newton said on this detail and even if he did say something it seems it was not developed over time like his other writing was.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Jim</i>
<br />It seems to me the acceleration of gravity is greater at the surface of a sphere than it is inside the hollow model and the same should be true for the solid sphere with a hole through it. And yet we seem to be saying the acceleration increases as we near the center of mass. There seems to be two things going on that oppose each other in these models.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">No. Velocity increases as the center of mass is approached. Acceleration decreases, and becomes zero at the center. The difference between velocity and acceleration is another of those background points in elementary physics that you are supposed to have already learned from books, whether in a classroom or self-taught. -|Tom|-

How do you get the increase in velocity that is indicated by the Kepler law if the acceleration is reduced to zero at the center of mass?