Answer:
What goes up and down without moving?
What has a ring but no fingers?
What is it that given one, you'll have either two or none?
What demands an answer, but asks no question?
I'm the start of eternity and the end of space. There are two of me in heaven and one in hell.
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?