Dr Measle wrote in message ...
Does anyone know how to derive the following formula?

Nb/Ny=(Omega-b*Ey)/(Omega-y*Eb)


I didn't know there was a formula to calculate the baryon-to-photon
ratio?

At first I thought this was a hoax, but I tried it with the latest
WMAP data and got 6.13 +/- 0.27 x 10^-10 which matches their result
almost exactly. I also checked whether the baryon-to-photon ratio
changed as T and H changed, but they both scale accordingly (H^2
proportional to T^-3) to keep the ratio strongly conserved (as it
should be).

[[Mod. note -- This at least appears like it might be a university
homework problem.

Really? Who gave you the problem and where did they find it? Has
anyone else ever seen this formula, or is it just me?

Alastair