Here is my interpretation of the catalyst, what it means etc., based on the feel of the song, the lyrics, and the placement on the album.
This song has multiple meanings, but they tie together. One is a religion reference and the other is a nuclear war.
The first verse describes the plight of humanity. I can be that we have fallen into sin, or that we are about to blow each other up. The second half refers to a fate that we cannot escape.
The second verse can be either literally humanity burning for its sins (continuation of falling into sin lyrics on the first verse), or being annihilate by nuclear war. The "a thousand suns" reference can refer to a hindu holy text that was quoted by oppenheimer at the first nuclear bomb test (ties meanings together). It mentions the splendor of the god being greater than "the radiance of a thousand suns". This could mean humanity being punished by a religious figure for our sins, but since thermonuclear bombs basically work like suns, it could be us annihilating ourselves. Again, the sin lines tie in here because it would be our own fault we blew ourselves up.
The chorus parts fit these as well. The "radiance of a thousand suns" religious reference or the literal blinding light of a nuke fit perfectly with the second line. Closing the eyes could be shielding your vision, or closing your eyes to think solemnly about the end of mankind, or even praying. The next part refers to humanity becoming only a memory in cold space, as all evidence of our existence decays away and echoes off into space. Far from the world of you and I could be everyone moving on to the afterlife or the memory of humanity fading into the distant reaches of space, as our last radio transmissions echo away (this is more literal tho). Oceans bleeding into the sky can be the seas literally evaporating at the end of the world, or a metaphor the end.
Lift me up, let me go to me is a way of saying "save me." It could be a prayer (said when eyes are closed) to be saved and let into the afterlife, or a way to beg humanity to save itself and not blow everyone up.
This is just my interpretation, but i think it fits well.
I think change in the song at about 3:25 fits with this, as it becomes quieter and more solemn feeling, almost with an end of everything kind of mood.
I picked these interpretations because it fits with the theme of minutes to midnight (the latest album that follows humanity through a cold war gone wrong type of scenario). I think the message is to change our ways before we destroy ourselves.
The song is near the end of the album, so the end theme makes sense, at least to me.