Make a Magic Disappearing Rainbow

Materials you'll need

• Index card (or sturdy white cardstock)
• Markers in rainbow colors (red, orange, yellow, green, blue, purple)
• Black marker or Sharpie
• Ziplock bag
• Tall glass of water
• Paper towels

 

Step-by-step tutorial

Step 1: Draw a rainbow on your index card using markers in rainbow order: red, orange, yellow, green, blue, and purple.

Step 2: Slide your index card into a ziplock bag and seal it.

Step 3: Outline each color stripe with a black marker to add bold black lines between and around each band of color. 

Step 4: Fill a tall glass with water.

Step 5: Dip the bagged card into the glass of water and look down from the top. Watch the colors disappear like magic!

• Pro Tip: Look from the top of the glass, not the side, for the best effect!

 

Learn more

When the bag is underwater, there's a tiny pocket of air trapped inside between the paper and the water. When light bounces off your rainbow, it hits that air-water boundary and gets bent so much it can't escape — so it never reaches your eyes, and the colors seem to vanish! The black outlines are drawn directly on the outside of the bag with no air gap, so their light travels straight up to your eyes as normal. Pull the bag out, and the rainbow is back. It was there the whole time!