The Pencil Boogie (a.k.a. Light Refraction)

I did an experiment on light refraction that I would like to share with you.  Light refraction is a change of direction in a light ray due to a change in speed.

I like to call this experiment The Pencil Boogie.  It's easy to do, but surprisingly fun.  Here's a video of the experiment:

Materials

• Pencil 
• Empty glass
• Glass full of water

Protocols 

• Put the pencil in the empty glass and look at it from eye level.
• Put the pencil in the water and look at it from eye level.
• Start to spin the pencil in the water slowly, then look at it from eye level.

What's Happening

• The light is playing tricks on you. Light moves slower through water than through air, so when the light enters the glass of water it slows down and changes direction.  When it leaves the glass, it speeds up again, making the pencil look bent.  This is called refraction.
•  When the pencil is put at an angle the light exits out at an angle, but if you hold it up straight the pencil still looks whole because the light is not at an angle. 

Signing Off,

Evalynn and Mom