Originally Posted by W1zzard
until about 300,000 years after the big bang, the whole universe was filled with plasma.
plasma is opaque to electromagnetic radiation = light can not travel through it
the cosmic microwave background that we see today is the first light that could move freely through the universe, and has reached us just now. due to the expansion of the universe its wavelength has been shifted down to microwave frequencies.
in theory it could be possible to observe something earlier using neutrinos, for which plasma is transparent. but it's incredibly hard to record neutrinos.
the aliens will "see" a sphere of same size as we do, but with the center around their own planet. the big bang happened everywhere at the same time, so there is no place where you could be, to be closer to it, to observe it any better
It's interesting that we live in just the right epoch to easily detect the electromagnetic 'artifacts' of the early universe. Probably nearing the end of such an epoch, as that electromagnetic radiation will slip into the Radio region of the spectrum and then attenuate even more, in a few billion years.
Are we in the 'sweet spot' of the Universe's evolution? The 'sweet spot' for possibly spring-boarding into long-term survivability on the cosmic scale. The perfect time to accumulate adequate knowledge of the Universe's early history, to tangentially inform our technological development?
Big questions, with no answers, but interesting.