Rocket ScientistEngorgement Charm

 

In Harry Potter and the Goblet of Fire, Fred Weasley administers an Engorgement Charm that makes Dudley Dursley grow a huge, purple tongue.

You can use the science of refraction to create an engorged finger of your own.

 

StarWhat you need:

  • A narrow transparent vial--about 1 to 1 1/4 inches in diameter
  • Masking tape

StarWhat do you do?

  1. Put a row of masking tape around the top edge of the vial.
  2. Secretly fill the vial with water. The row of tape hides the upper surface of the water, making the vial look empty.
  3. Show your audience your "normal" index finger.
  4. Then say, "The Engorgement Charm is concentrated in this very special vial. Behold as my finger enlarges under the power of the charm."
  5. As you put your finger into the container, it appears to enlarge in diameter to twice its normal size.

StarHow does it work?

When you place your finger inside the vial, refraction occurs as light reflects from your finger and moves through the water into the surrounding air. As the light rays move from one medium to another, they are bent, creating the illusion of an enlarged finger. This is the same way a magnifying glass works.