What Am I Riddles

Question: I'm a measurement of time.
But you'll find me on a map, not a clock.

What am I?

Question: I can go up a chimney down but not down a chimney up?

What am I?

Question: I am pain, I am fear, I will take what you hold dear, Nations shudder when I'm near, Many die when I'm here. What am I?

Question: What's higher than mountains, Smaller than trees?

Question: I rule the ends of the universe. I control its laws. I reign the galaxy. The start of space is the start of me. The end of the universe is the end of me. The name of my slaves bring mighty terror to you. The universe wouldn't work if it wasn't for me. What am I?