Are we observing a collision between another parallel universe?
Scientists used the microwave background radiation coming from far away from the universe to understand the behavior of the early universe. We know the universe is expanding; also there are theories that there can be other universes out there due to rapid expansion. This was initially proposed by Alan Guth in his inflation theory.
However if our universe continues to grows, there is a possibility our universe can collide with the edge of another universe. It is something like two bubbles merging in the air. According to the scientists if this happens in early age of the universe, we may be able to spot that in the cosmic microwave background, as huge temperature fluctuation.