What you need:
• Two apples
• String
What you do:
• Attach a piece of sting to each apple.
• Have each hand hold one string so that the apples are at nose-level, 6″ apart.
• Blow hard between the apples and watch them move!
What should happen:
• The apples will get closer to each other.
Why does that happen:
• The air pressure is lowered as you blow between the apples (think of the air molecules as ping pong balls … they balls don’t have enough time to touch the apple surface as they zoom by).
• The air surrounding the apples that’s not really moving is now at a higher pressure, and pushes the apples together.