text: Hi!\nFirst of all, if the galaxy ends... so does the earth since the earth is part of the galaxy!\nI don't think there are any theories as to the end of any galaxy specifically, but there is a theory that the Universe is currently expanding from the time of the Big Bang (which is scientifically considered the beginning of the universe) and one day, the universe will stop expanding and start to contract.\n\nSo, in simple terms, scientists believe that the universe strated from a single point in empty space, that point exploded into the universe (an event called the Big Bang) and since then, all the objects in the universe (all the galaxies etc.) are moving away from this point. Basically the theory says that the explosion is still going on and will continue for a few billion more years. At some point in the future, the objects in the universe will stop moving away from the point of the initial explosion. Once that happens, scientists have different theories about what happens next. \nSome believe that the universe will just stop moving and stay that way forever (Steady State Theory). Some believe that gravity will pull the whole universe all the way back to the starting position and then the whole universe will become a single point in empty space again (just like in the beginning) and that will be the end of the universe. Other scientists believe that when the universe returns to that same point again, it will explode again, and so this will keep going on forever (I.e. the universe will keep exploding and reforming and exploding over and over again). There are some other theories but these are the main ones.\n\nRegardless, scientists believe that we may never know what will happen because almost all scientists agree that in 5 billion years time (or so) the sun will die (also known as "going nova") and in its death will burn the entire solar system in what we call a nova explosion. So unless we can find another planet outside of this solar system to inhabit, we won't see the end of the universe!\n\nSuddenly believing in God seems like the much safer option - at least we have a chance then!\n\nSorry, I just want to reinforce this comment, the sun WILL NOT go supernova and become a white dwarf it is far too small, it can only go nova (becoming a red super giant - which actually makes it the size of the solar system not just to mars' orbit - remembering that the nova is in fact an explosion, the surface of the sun is blasted outward and is likely to go beyond the edge of the solar system) and then the core will collapse on itself.\n\nHope that helped,\nFahed