not sure where to post this question... kind of a thought experiment... if a mass is given an initial force in a frictionless environment, like space. it would continue to move forward away from the applied force at a constant rate until acted upon by another force. if you were to remove some of the mass without affecting the remaining mass in any other way, the velocity of the mass should increase in order to keep the F=MA equation balanced. well, if the initial force is the big bang. and the stars/galaxies are the mass moving away from the big bang at a "constant" rate. as the stars slowly turn mass in to energy through fusion, shouldn't the stars slowly accelerate as they lose mass? or rather, wouldn't this be a better explanation as to why stars appear to be accelerating than the vague concept of dark energy? or, at least, could this explain away some of the acceleration?