Why gravitational force is attractive?
- Some where it was written that gravitons are hypothetical particles which mediates the force of gravitation, and it has a spin of 2 , and Quantum field theory had proved that any particle of spin 2 characteristic will always mediate attractive force. But this theory is not yet proved .
- And it was written somewhere that there is an exceptional case for gravitational force to be attractive. Ie dark energy is a case of gravitational repulsion and it is responsible for the expansion of universe. And it is due to the negative pressure effect of dark energy, what is this?
- What if the existence of gravitons particle is proved, then how this theory will explain dark energy.
- Some people say that gravitational force is always attractive because mass can never be negative, why we are talking about negativity or positivity of mass , why we are comparing it to the electromagnetic force(just like positve and negative charges repels and there is no negative mass therefore no repulsion)