I What was expansion speed at the time of the CMB?

sjordannc
Messages
1
Reaction score
0
To be clear, I'm looking for the speed at which points in space were moving apart from one another in the universe as it existed 370000 years after the big bang, not the Hubble parameter (expansion rate) derived from our current distance within our current time.

Thanks in advance!
 
Space news on Phys.org
Why are you interested in specific 370000 year after bigbang and not current Hubble parameter ?
 
sjordannc said:
the speed at which points in space were moving apart from one another
There is no such thing. The "speed" depends on how far apart the points are.

If you want to know the Hubble parameter at the time you give, that is a single meaningful number, but it's not a speed.
 
sjordannc said:
I'm looking for the speed at which points in space were moving apart from one another
The problem with this is that Hubble's law says that the recession speed is proportional to distance. So we can tell you the Hubble parameter back then, or we can tell you the recession speed of points a specific distance apart, but there is no single recession velocity. Not then and not now.
 
Back
Top