What is the correlation between air cell growth and incubation days?

[RightFromtheStartDoula]

I have noticed that as the days go on the air cell on most of my eggs is getting quite large...I had circled it in the begining so that I could tell top from bottom...and now the pencil mark is way off ...

So what is the correlation between air cell growth and incubation days?..

Is it a good indication that all is going well?

Would an air cell continue to grow if the chick is dead?..

Can you predict when you might get a pip based on the size of the air cell?...

 

[Ruditchka]

Here is a link that shows approximate air cell development in eggs at different stages of development(roughly at center of page is diagram): http://www.thepoultrysite.com/articles/166/care-and-incubation-of-hatching-eggs