Light years and redshift from our point of view. How can we see it? So I was reading about GN-108036 this morning and for some reason I thought of something which I can't quite wrap my head around and make sense of.  It's early morning so maybe coffee hasn't kicked in yet.
If it starts with a central big bang and we now look at something that is 12.9 billion light years away, how can we be here already to "observe" the light if the universe is approx. 13 billion years old?
In other words:
Big Bang, stuff starts expanding.
What will form GN-108036 is part of it
What will eventually form earth is part of it.
Nothing can travel faster than light yet;
12.9 million years after we are at this point "ahead" of the light from GN-108036 to see the light reaching us?
 A: 
Nothing can travel faster than light yet

The expansion of the Universe itself can.
There are already parts of the Universe receding from us "faster than light". This is because every small part of the Universe is expanding only a little - but if you sum it up over cosmic distances, the expansion speed, total over a large distance, becomes huge.
So, in a sense, nothing actually moves faster than light. It's just that the Universe is so big that this tiny space expansion actually adds up A LOT over large distances. Space itself is growing, and it's not subject to relativistic limitations - only things moving through space are limited by c.
Back to your original question: there was a time, early on, when the Universe expanded much faster than today. It went from essentially nothing to a huge size in almost no time. Things that were previously close together, all of a sudden found themselves separate by large distances. So, those photons emitted 12.9 billion years ago, might have arrived here a very long time ago, if it were not for this sudden "additional" distance in between.
BTW, this is not entirely rigorous, but it's good enough as a pop-sci explanation, and at least will get you started.
