Answer:
The more there is the less you see.
I am an object which is used in baseball during the day I can't be seen at all
I have wheels and flies yet I am not an aircraft.
I am as hard as metal, yet as flimsy as glass. I shine like a star, yet I am only a rock. What am I?
I go in hard come out soft. Blow me hard and I’ll make a pop.
Brings the sky a lot closer.