Re: Why does a fan turning one direction cause another fan to spin opposite?

Dear Bonnie Kate
When you have a look at your Christmas fan you'll notice that the blades are 
tilted in a certain direction. If air comes from below it will "hit" the 
blades and make the fan turn. You'll easily work out the direction and 
later you can check it by lighting the candles. The ceiling fan produces a 
downward air stream, the air hits the blades from the other side and the 
fan turns in the opposite direction.