On Sun, 4 Dec 2005, Ed Kelly wrote:
PMPD would be a good tool for exploring gravity - but you would have to explore the escape velocity scenario, where links (springs) are broken if an object attains a certain angular momentum, and a different (repulsive) mechanism comes into effect
It wouldn't be a good model because the ideal spring force is proportional to distance, whereas gravitational force is inversely proportional to the square of the distance when assuming pointlike masses.
The only case where gravitational force is sort of (sort of!) like spring force is if you go inside a large object of uniform density. obviously you don't have orbits inside there.
Going over escape velocity does not change the nature of gravitation and doesn't cause repulsion. Escape velocity is a natural consequence of the inverse-square force (gravity or electricity).
The repulsion you are thinking of may be caused by centrifugal force, which only appears when the observer (the referential) is rotating.
Gravity works beyond escape velocity. It's just that beyond escape velocity, it isn't dominant anymore. To compute gravity, you need to take *all* of the possible particle pairs into account, so for N masses you need N*(N-1)/2 springs, all of the time.
_ _ __ ___ _____ ________ _____________ _____________________ ... | Mathieu Bouchard - tél:+1.514.383.3801 - http://artengine.ca/matju | Freelance Digital Arts Engineer, Montréal QC Canada