According to particle physics, there is a certain particle called a graviton which is the messenger particle of gravity but it so happens that Einstein's theory of general relativity says that mass affects the space time fabric which is responsible for gravitational force. So it is like the apple on tissue paper analogy. Place an apple on a tissue paper and the tissue paper will bend downwards. The thing that I do not understand is that if general relativity says that if mass affects space time (gravity), then why do scientists keep searching for the graviton particle? Surely a graviton particle would somehow violate general relativity? Secondly, since gravity affects space and time, it seems intriguing that graviton particles can affect time? I know gravitons have something to do with string theory and trying to unify general relativity and quantum mechanics but still it seems strange.