- #1
Gerinski
- 323
- 15
The period from the end of recombination until the birth of the first stars is commonly referred to as "the Dark Ages" since no starlight existed yet.
But the cosmic bath of photons at that time which today we call the CMB was still hot, not yet having redshifted. It is usually said that temperature at the end of recombination (CMB) was around 3000 K, which would mean that the universe would have been glowing bright yellow, and as it expanded further the bright yellow would gradually become more orange, then redder and gradually fainter until it finally went into the infrared and therefore truly dark.
If so, the Dark Ages may be an inappropriate name, at least for the initial period?
By which age would the cosmic radiation have transitioned from red into the infrared so the skies would really look dark?
TX
But the cosmic bath of photons at that time which today we call the CMB was still hot, not yet having redshifted. It is usually said that temperature at the end of recombination (CMB) was around 3000 K, which would mean that the universe would have been glowing bright yellow, and as it expanded further the bright yellow would gradually become more orange, then redder and gradually fainter until it finally went into the infrared and therefore truly dark.
If so, the Dark Ages may be an inappropriate name, at least for the initial period?
By which age would the cosmic radiation have transitioned from red into the infrared so the skies would really look dark?
TX