Hello everyone! I am a new member, and this is my first post. I am a engineer by training, but I have always enjoyed physics. I have been reading a number of books lately about Quantum Physics, and there are a number of things I still don't understand. But there is one question in particular that I have been wanting to ask a physicist. Imagine my surprise when I stumbled across this web site today at work. My question concerns the force carriers. In particular, I am referring here to gluons (Strong force), and gravitons (the Gravitational force). I am having a very hard time understanding how a particle travelling between two points (such as a gluon or a graviton) can transmit a force that has the effect of "pulling" the objects together or closer, as is apparently done by the Strong force and Gravity. It is much easier to understand how a partical that strikes another can "push" it away, but I am having a hard time getting my mind around how a partical can transmit a force that "pulls". Especially at such HUGE distances over which gravity works. Now I understand that gravity is really just curvature of space, so are gravitons and gluons somehow curving space and therefore causing these forces? If you can, please try to answer in laymans terms so I can understand. And thanks in advance.