Answer:
Until I am measured, I am not known. Yet, how you miss me when I have flown. What Am I?
I am the same written forward backward and upside down.
Fashions change, but what can a person wear that is never out of style?
I am between earth and heaven. What am I?
A hole in a pole. Though I fill a hole in white I'm used more by the day and less by the night
I will disappear every time you say my name.