- #1
Doctor Strange
- 31
- 2
The value for the red-shift of the CMB is 1090 according to the latest Plank study. How do they arrive at this number? You can look at how hydrogen lines of supernovae light are shifted, but how do you tell how far light is shifted when looking at the light from a primordial soup? Is there some absorption lines or do we know at what temperature Hydrogen becomes stable (and thus neutral and thus transparent), calculate the age of the universe and then use the age to calculate the red-shift?