How to calculate the 130 billion LY radius of curvature

[Martin]

Ned Wright has provided us with a "best fit" value of Omega = 1.011

 

George Smoot has some undergrad coursenotes where he shows how to derive the radius of curvature from Omega.

 

Essentially you take sqrt(Omega - 1) and divide the Hubble distance by that.

 

Omega - 1 = 0.011

and the sqrt of that is 0.105 which is about a TENTH

And the Hubble distance, c/H, is about 13 billion LY.

 

So you divide that by a tenth, and you get 130 billion LY.

 

actually it is 13.8 divided by 0.105, but it comes out the same

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Wright and Smoot are colleagues, they worked together on COBE (where Smoot was a leader)

and now Wright is leading WMAP, which is the followup, COBE the Second.

So it seems appropriate to use Smoot's notes to interpret Wright's paper.

 

The course is Physics 139 at Berkeley, an advanced undergrad course in Special and General Relativity with some Cosmology thrown in for good measure. You can get his notes if you google "smoot notes geometry universe".

 

Let me know if you spot an error. I'd be glad if anyone catches a mistake.