This was my reply to a question on The Big Bang in a Facebook forum, asking if the stars didn’t exist, how humanity was still the same even though we couldn’t, for instance, develop navigation with the stars without stars.
My answer:
Time was dying. It’s like taking parts out of history, while the rest of history is kept intact (though weaker and weaker until the universe will eventually collapse as there won’t be enough history left)
That’s what the crack does, it erases history part by part.
If time is a video tape, and it’s crumbling apart, scene 1 and scene 3 could happen even if scene 2 is gone, because it’s a video tape and the pictures are still on it.
That is because (and I’m saying this in all seriousness, not as a way to avoid actual explanation) time is not a linear progression of cause to effect. The effect being the world 2000 years later (with satellite navigation etc), the cause being lack of stars. We assume that one causes the other but (under the show’s physics) if you remove the cause, the effect may still exist.
Why? Ball of wibbly wobbly timey wimey stuff. It’s supposed to be beyond our level of understanding but we can imagine the video tape mentioned earlier, the one that has all the scenes from our lives in it, tangled into a big ball.