Speaking of Splinters...

I realized after some time of talking about these splinters and distortions in the space-time continuum that I haven't really explored the science of it all as much as I should have. So, here's a handy little extra-universal visual for you to reference.
Still doesn't help? Here, let me explain it further.

This is imagining space in terms of n-dimensional time. Universes are simply collections of hundreds of trillions of objects all surrounding a certain indeterminable center. Since these centers travel through time and not space, these may be represented as strands, and all of the objects in them are strands orbiting the center (e.g., planets in a solar system, stars in a galaxy, etc.) Of course, this interpretation of "strings" leads to quite a few entanglements. Some simply alter events farther down the line indirectly, such as the tying of shoes a certain fashion could lead to a different person in another country to order coffee instead of tea. However, too much pressure on anything can lead to a breach.
When such a breach happens, the flow of time is interrupted across all of existence. (Based on the diagram, it may not really be the flow of TIME as much as the flow of the universe THROUGH time, but the idea still applies.) Broken splinters of the now-decimated universe make its way into other strands of space, colliding with other realms and linking hundreds of worlds that otherwise could never have met. Since these are representations of n-dimensional time, the only worlds earth has to worry about are pieces of its own past and future.
Oh, wait...

Rendered in Photoshop