The End of Everything (Astrophysically Speaking)

by Katie Mack

If looking farther away means looking farther into the past, and if there was a time in the distant past when the universe was basically one big all-encompassing fireball, then it should be possible to look so far away that you see a part of the universe that is still on fire. Or, thinking about it another way: if, 13.8 billion years ago, the whole possibly infinite universe was aglow with radiation, there should be parts of it so far away that the radiation from that glow is only just now reaching us, having traveled through the expanding, cooling space all this time. In any direction we look, if we look far enough away, we’ll see that distant fiery universe. We’re not looking at parts of space that are any different, but rather at a time when ALL of space was on fire.