Random Question If Anyone is Interested

[helenv]

I was just wondering:

When someone sticks their hand in a powerpoint and it's on, how does the electricity know that we've created a closed circuit with the ground for the electricity to run? Usually in a normal circuit/battery-thingie-that-we-usually-make-in-physics there is a positive and a negative terminal. The current will run from the positive to the negative because of ...the magnetic pull? Anyway there's that magnetic attraction that will pull the current through a circuit. Whereas in the situation above, is the ground a negative terminal and the powerpoint a positive one? How does the electricity know?

Just a side note, my teacher compared this to the magnetic field of planets (i think). Does anyone know why planets and stuff tend to spin in space?

It'd be great if someone could explain this.

Thanks a bunch! 

[MissIraq]

because god created it like that.