The Sky in 350 Billion Years

I don't have any letter after my name and I don't have a higher level of education but I do have a very analytical mind.  Surely if the world is flat then so is the universe and thing are just falling of the edge?  Kidding...   You may find the the increase in the acceleration curve matches the reduction in the gravitation pull between the matter that is expanding.  Like firing a rocket info space with enough force it would exit the pull of gravity and with no real friction it would continue.  Not proven, just a thought.