prologos:
"Picture the next star to the Sun to be 2 instead of 4 light years away; welcome the changes to come."
Stars do not need to hit each other in order to create massive chaos. Even with our relatively distant stars in the arm of the Milky Way the gravitational effect of each other could be enough to pull a planet at least a few tens of millions of miles from its stars orbit. That could be enough to freeze a planet.
There will also be the union of the two massive black holes that are believed to exist in the center of every galaxy including ours. The detonation of two black holes joining together will be enough to fry many star systems close to the center and possibly our sun which is somewhat distant from the center of our galaxy.
Just the radiation released from such a detonation could endanger life on Earth.
Just look at the chaos below and give me your opinion.