I think the world will end in fire or black holes

So, stars have two ends:

1. They constantly expand, engulfing anything nearby until they simply spread into gas

or

2. The force of gravity increases faster than the star can expand, which causes it to condense into a super dense point that eats light (and anything else around it).  A black hole.

This is our universe, there are billions of these objects floating around through space.  When they finish their life cycle, a catastrophe occurs to anything around it.  As for earth, I created a diagram: