What Am I Riddles

Question: It brings light to a dark dark world,
In a current it travels and through tunnels it's hurled.
Touch it and it'll kill you.

What is it?

Question: I used to fill rooms but now I'm a tower,
I can stay put or I can travel far.

What am I?

Question: These are the three lives of mine:
So gentle I soothe the skin,
So light I caress the sky,
So hard I crack rocks.

What am I?

Question: I have no wings but I fly,
I have no teeth but I bite.

What am I?

Question: When I'm born, I stay in the sun A little time, and I make crazy When I'm old, I'm worth a fortuneWhat am I?