This website puts forward the conjecture that the gravitational constant, associated with each mass, depends on the proximity of other matter. This leads to a natural solution of the flatness problem.
If the strength of gravity were to decrease for regions
of dense matter, bangs could
occur due to 'bounces' of dense and collapsing masses. As the
pressure and temperature increased, the outward forces would
If the strength of gravity decreased, bangs would
occur leading to be observed foam like large scale structure.
Conjecture: The attractive gravitational mass of an object varies, depending on the proximity of other matter, in order to keep its total gravitational potential energy equal to its rest mass.
If the conjecture is true, LISA (the space based gravitational wave detector) may detect solar oscillations, which would change the sun's gravitational mass.
The shape of 'galactic rotation curves' may be explained by the conjecture.