I've never quite understood the theory behind why dark matter and dark energy exist. I know it has something to do with gravitational pull being stronger than what we calculate it SHOULD be, could ...
AS the articles on the web suggest, Dark energy is the reason behind the expansion of universe. If so, why isn't it getting used up in doing so. And consequently, the rate of expansion should reduce! ...
Is it possible that dark matter particles are unstable and the existing dark matter will decay in the long run and turn into hydrogen, for example? What would be possible mechanisms for such a decay? ...