Hi ediso74, thanks for the question. Gravitons are the modulators of the gravitational force just as photons are the modulators of the electromagnetic force. Theory predicts that gravitons travel at the speed of light (they can’t travel faster; they could travel more slowly); and observations of gravitational waves by NSF’s Laser Interferometer Gravitational-Wave Observatory (LIGO) are consistent with gravitons moving at the speed of light.What are your thought on gravitons ? Why is there the thought that the mechanism of gravity would work via particles ? Also hypothetically, if an immense black hole just 'popped' into existence 4 light years away from me, would the gravity of the black hole take 4 years to affect me ? or would the effect be instantaneous with the appearance of the black hole? Is there any experimental evidence of the 4 year or /instantaneous effect?
Yes, if a black hole suddenly appeared four light years away it would take four years.