Reading this article, I am realising that Steemstem is becoming my primary source of cosmology news! Cool article, @Lemouth.
Comments:
The first one suggests that the Cosmic Dawn occurred about 180.000 years after the Big Bang. However, a second dip was observed at about 250.000 years after the Big Bang.
I suppose you mean 180 Million and 250 Million years respectively, because I do not see how the first stars could form in the plasma before the emission of the CMB!
Some intriguing signals of the cosmic dawn epoch (i.e. the coolest period of the universe history also corresponding to the moment at which the first stars appeared)
I don't understand this. Considerinf the universe as a black body, temperature at a given time is determined by the average wavelength of CMB radiation. Saying that the coolest period of the universe was in the past does not make sense to me (Reason: Red Shift of CMB due to expansion of space).
And a little wink ;-)
This ‘line’ corresponds to the transition between the two hydrogen ground states with total spins respectively equal to 0 or 1. This is a crucial number as in the low temperature conditions of the universe at that time, it consists of the only observable hydrogen transition.
The hypertext link about the crucial number leads the reader to SETi's wikipedia page. was this intended?
Thanks for this great article. it was the first time I met the EDGES experiment!
Thanks a lot for your comments! You are right twice :)
Good catch! A bunch of zeros decided to stay inside the keyboard. It is fixed :)
My wording is in fact not appropriate and sloppy. I was actually not meaning the temperature of the universe (even if this is what I wrote), but the temperature of the hydrogen gas instead. Before star formation, the primordial gas just cools adiabatically. I will fix the post in a minute.
Yes! The 21.1cm transition plays a big role in extra-terrestrial intelligence searches.