B Standard candles in a stretching fabric of space

[Rebbyte]

I'm just trying to figure somethings out concerning the accelerating expansion of the universe and the measured redshift, etc.

If a light emitting object moves away from us, because of the expansion of the universe, the speed of that object causes a redshift in this light. But this light, from the time it is emitted to the time it is received, also travels through an expanding fabric of space. Like if it travels through a stretching rubber band. This will also cause a extra redshift. So long distance objects will appear to be accelerating away.
Since the expansion of the universe stretches the rubber band, the traveled path will also be longer than only causing by the movement of that object.
How is this been accounted for in the measurements and formulas for the use of standard candles?

 

[Bandersnatch]

If a light emitting object moves away from us, because of the expansion of the universe, the speed of that object causes a redshift in this light. But this light, from the time it is emitted to the time it is received, also travels through an expanding fabric of space. Like if it travels through a stretching rubber band. This will also cause a extra redshift.

This is the same thing. Specifically, the recession velocity of the observed object at emission alone does not cause its redshift. It's the accumulated Doppler redshift between infinitesimal point to point distances along the path of light that we observe. So that the expansion history matters, not just the state at emission.

So long distance objects will appear to be accelerating away.

This does not follow. The exact same thing happens regardless of whether the expansion is accelerating or not.

How is this been accounted for in the measurements and formulas for the use of standard candles?

This is not straightforward. Take a look at this Wiki page (and the sub-pages for various distances):
https://en.wikipedia.org/wiki/Distance_measures_(cosmology)

 

[Rebbyte]

This is not straightforward. Take a look at this Wiki page (and the sub-pages for various distances):
https://en.wikipedia.org/wiki/Distance_measures_(cosmology)

Thank you, I will look into that.

 

[alantheastronomer]

Since the expansion of the universe stretches ...the traveled path will also be longer than that only caused by the movement of that object.

That's a very astute observation! In fact it's a big problem for astronomers to be able to separate the what's called "peculiar" motions of the standard candles from their cosmological ones due to the expansion of the universe. These peculiar motions include the motions of their host galaxies due to the gravitational attraction of the clusters they're in, and their rotational motions within their host galaxies. These motions cause a statistical scatter that introduces uncertainty in the calculation of their distances, and is a bane to researchers!