Experiment: Arm Shortener

Don’t worry, this won’t really shorten the length of your arm!

You’ll need:

• Yourself
• A wall

What to do:

1. Face the wall and stretch one of your arms out in front of you so that your fingertips barely graze the wall.
2. Keeping your arm straight, swing your arm down and back behind you, then back to its original position in a single motion.

How it works:

If you did the exercise correctly, your fingers should not be able to reach the wall anymore. Your arm isn’t actually any shorter than it was a few moments ago. For some bizarre reason, when you bring your arm back, you lean back with it and when your swing it forward, you don’t return to your upright position.