The Cosmic Microwave Background is 13.7 billion years old, yet is currently located at a distance of 46.5 billion light-years. It was emitted when the Universe was around 380,000 years old, the cosmological redshift of this Cosmic Microwave Background is approximately z = 1100, meaning the Universe has expanded 1100 times in size since what we can detect, was emitted. We see these figures all the time.
But what about the Gravity Wave Background emitted at the very instant of the Big Bang, or the Neutrino Background one second later? If we can ever detect the very first gravitational wave of the Big Bang, how much further is the radius of our Detectable Universe pushed outward?
“Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.”
― Douglas Adams, The Hitchhiker’s Guide to the Galaxy