B Calculating Distance: What Am I Doing Wrong?

[Discman]

What I'm doing wrong?
speed X time = distance
0,6 c X 380000 jr = 228000 ly
times expansion of 1000 gives 228.000.000 ly
This is equal to about 72 Mpc
Why is the standard ruler 2 times as long: about 150 Mpc
What is wrong, or do I forget in my calculation?

 

[mfb]

What exactly do you want to calculate? Where do those numbers come from?

A (!) standard ruler is any object of known size.

 

[Discman]

With these numbers I am pointing of course at the cosmic standard ruler which is used in the BAO.
Speed fundamental tone of acoustic waves 0,6 c, time to sound horizon 380.000 yrs
And the calculated standard ruler is the radius of the sound horizon shell (not the diamater)
So, again, why 2 times so long?

 

[Bandersnatch]

speed X time = distance
0,6 c X 380000 jr = 228000 ly

I think that should be conformal time. What you did is calculate sound wavefront distance as if it were traveling in a non-expanding space.
See here:
https://books.google.pl/books?id=RZ...=0ahUKEwiFuqH4yeLRAhViYpoKHZwXA7k4ChDoAQgoMAU
(down the page)
Plugging in $\eta_*=0.9Gy$ gives roughly the thing.

 

[Discman]

Thank you very much. By coincidence I was just beginning to think into that direction when your answer arrived.