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Further..
I personally dislike the bowling ball on a rubber sheet approach.
I better representation would be to have the ball under the rubber sheet and that the sheet is stretched towards it but that stretching is actually compacting the rubber��. And the other problem with the rubber sheet is that the rubber stretches around the ball whereas GR tells us the opposite is the case...the rubber sheet is useless to represent the grid and perhaps that approach could confuse folk...in my view.
GR is our best model of gravity however one must remember that Newton's Gravity (often out down by those telling us how wonderful GR is) is still used for all space travel. As far as I can tell GR is only needed to construct models of black holes and plot gravity waves...although both Special Relativity and General Relativity are used for GPS. The application of one tells us we "see" a satellite going slower and the other tells us we "see" a satellite going faster and it is by combining the two results that a picture is created that enables the complex geometry of GPS to work.
GR provides no mechanical explanation or perhaps what is going on at a quantum level...those involved in GR do not seem to like having that pointed out but as a layman speaking on matters that perhaps I should not I believe that at some level GR describes the result of countless particles creating in effect a pressure system...if nothing else it remains unknown how the message of gravity works...in my view there must be some particle that works to convey the information that enables mass to tell space how to bend...else we are left with a proposition that it all works by the magic of the equations of GR..some would have it so no doubt.
We do have a hypothetical particle under consideration which is at this point referred to as the graviton but it has yet to be identified via experiment.
I still think there is something to the LeSage approach that sees gravity as a predictable result of countless particles making up space. The idea is these particles travel everywhere and not slowed much by passing thru matter..so to explain gravity on the Earth one need imagine that the particles travelling thru the Earth present less force than the particles reaching us from directly above and the particles from above in effect win and push us to the ground. Gravity in this hypothesis can not been seen as a force of attraction of course...hence my statement with my head shot...gravity does not suck.��.
Alex
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