What do you think of the strong nuclear force? Gluons are the force carriers between color-charged particles. And gluons themselves have a color charge. So gluons transmit force between each other. Does that mean the universe is already too strange to exist?<p>By the way, this is why the strong nuclear force has such a short range. Gravity has infinite range as far as we can tell, so that makes it unlikely that the graviton, if it exists, has mass.