Of course, Felicia fails to point out what makes worrying about the Milky Way colliding with Andromeda in three billion years truly silly. Homo sapiens will have long-since become extinct, if not by our own hand, simply through the inexorable cycles of biological and planetary evolution. We will be long, long, long gone. To put this in perspective, the oldest ancient fossil microbe-like objects are dated to be 3.5 billion years old, just a few hundred million years younger than Earth itself. That's the timescale we're working with here.
Of course, there are the grotesquely optimistic idiots who imagine all the galaxy as our future suburban sprawl...