I also have to try to accept the fact that as an air vehicle moves away from an observer, basically, it does not get smaller and smaller. and that no matter how far away it is, it will always be a point source to the human eye.
I have a very hard time with that.
what if the object was a fly at 100 miles?
well, just saying?!?!?! everything has limits.
Ok Polaris, the North Star, has the same Angular diameter as a 1/4 inch Fly at 248.12 miles! It's the amount of light not the Angular size that allows you to see it.