Answer:
What can be measured but not seen?
Runs smoother than any rhyme, loves to fall but cannot climb!
I don't think or eat or slumber. Or move around or fear thunder. Just like you I look the same but I can't harm you or be your bane.
Long and think, red within, with a nail at the end.
It is a path of cow juice spread across the sky but cannot be seen by the naked eye
If you can spot one of these eastern warriors, it means they're not doing their job right.