Hmm..How would the universe actually end though? Could this universe be a small part in a bigger one which is a small part in a bigger and in another bigger one and etc.
well, there's simply a point where time and space cease to exist. It's nearly impossible for the human mind to comprehend. Saying that this universe could be part of a bigger one is pretty much pointless because there is no evidence to suggest anything of the sort. Also, the universe is going to die in about 100 billion years just so everyone knows.
Also, to fire, ya it's almost impossible for there not to be alien life out there, however at this point there is up evidence for it. That's all saying.