Answer:
What can be measured but not seen?
It is more feared than fear itself, And no one can escape it. It takes no sides and does not judge, it does not know to hold a grudge. It is the most clearest result, Of how life beats you by default.
You can always see it, but it's too far away to touch. Mountains rest on it, and at sea it surrounds you. What is it?
I have a face, yet no senses. But I don't really care, because time is of the essence.
This thing runs but cannot walk, sometimes sings but never talks. Lacks arms, has hands; lacks a head but has a face.
I have two eyes in the front and a lot of eyes on my tail