Answer:
Dies half its life. Lives the rest. Dances without music. Breathes without breath.
Sharp and long, flag of the world. What is it?
What can be heard and caught but never seen?
It is weightless, you can see it. If you put it in a barrel it will make it lighter?
Though easy to spot, when allowed to plume, It is hard to see, when held in a room.
What is always coming but never arrives?