Demonstration of a Principle:
    Conservation of Angular Momentum, or CAM for short.
         It matters where you put things that spin.

Demonstration:
 

Arms Out	Arms In

    Allow yourself to be spun with your arms out.
    Pull your arms in.  You turn faster.
    Why?

Answer:
    In order for angular momentum to be conserved, your body has to turn faster.

Reality Check:
    The real world is complicated by things like friction.
    Pirouettes "run down" because of toe friction with the floor.
    Skaters spin more easily since the ice reduces friction.
    CAM does not account for friction.

Extra Credit Formula:
    I₁ w₁  = I₂  w₂
Means
    I =  ease of spinning - how much force it takes to set the body spinning
    w = rate of spinning - how fast the body is spinning