Beyond CMB

  • Thread starter CosmiCarl
  • Start date
7
0

Main Question or Discussion Point

Is it accurate to say:

The Light-Year distance from earth to the Surface of Last Scattering (= CMB location) EQUATES TO the Age of the Universe (13.73 Gyr)? (ignoring units conversion factors).

Would an observer, say 13.0 G Light-yr from us, ALSO see the CMB the same distance away?

Where is our Particle Horizon thought to be located, relative to the CMB? (Or Cosmological Horizon, whichever is greater).

Is it presently thought a significant portion of the Universe lies beyond our Particle Horizon? If so, would not at least a part of that portion have to be OLDER than anything we can observe, including the CMB?

Thanks in advance for everyone's time and thoughts!

CosmiCarl
 

Answers and Replies

marcus
Science Advisor
Gold Member
Dearly Missed
24,712
783
Is it accurate to say:

The Light-Year distance from earth to the Surface of Last Scattering (= CMB location) EQUATES TO the Age of the Universe (13.73 Gyr)? (ignoring units conversion factors).

Would an observer, say 13.0 G Light-yr from us, ALSO see the CMB the same distance away?

Where is our Particle Horizon thought to be located, relative to the CMB? (Or Cosmological Horizon, whichever is greater).

Is it presently thought a significant portion of the Universe lies beyond our Particle Horizon? If so, would not at least a part of that portion have to be OLDER than anything we can observe, including the CMB?

Thanks in advance for everyone's time and thoughts!

CosmiCarl
You are off by about a factor of 3, Carl.

The present distance to the last scattering surface is estimated to be about 45 billion LY.
 
7
0
45 Glyr

Thanks, Marcus.

Is that number only theoretical, or is there some obsevational data to support it?

CosmiCarl
 
Chronos
Science Advisor
Gold Member
11,398
738
That number is theoretical, Carl. It is possible the universe is larger than we can observe, but irrelevant. The unobservable portion, if any, will be forever unobservable. Such theories appear suspiciously similar to a temple priest fishing for disciples.
 
Last edited:
Wallace
Science Advisor
1,249
0
Thanks, Marcus.

Is that number only theoretical, or is there some obsevational data to support it?

CosmiCarl
This comes from observations, and the theory that has been developed given those observations. You can't directly point a telescope somewhere and find this kind of information. This, and related things such as the age of the Universe are always 'theory dependent', so if a different theory comes along that also explains the observations, but is favoured for some other reason (or by newer data) then these 'theory dependent' numbers change, even though the observations don't. Therefore you can't say they are determined either by theory or observations alone, the combination of the two is what defines these types of quantities.
 
Last edited:
7
0
Older than the Universe?

I understand all the underpinnings, thanks, guys.

But now I am a little confused:
If the age of the universe is thought to be 13.7 Billion Years, and nothing can travel faster than light, how can anything be more than 13.7 Billion Light Years distant? This just seems logically impossible.
 

Related Threads for: Beyond CMB

Replies
5
Views
873
  • Last Post
Replies
3
Views
783
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
6
Views
3K
  • Last Post
Replies
1
Views
544
Replies
5
Views
6K
Replies
11
Views
832
Top