Jelly Marble Secret Message

Write a secret message that is hidden by Jelly Marbles.

Use Jelly Marbles to hide a secret message.  When you are ready to reveal the message, just add water!

Experiment Materials

  • Jelly Marbles
  • Clear dish
  • Water
  • Paper
  • Markers

Experiment Videos

Experiment

1

Grow the Jelly Marbles by adding 1 tsp of dry Jelly Marbles to about 9 oz of water.  Allow them to sit for several hours to grow to their full size.

2

On a piece of paper, write a secret message or draw a picture.

3

Scoop the grown Jelly Marbles out of their growing container and transfer them onto a clear dish.

4

Place your secrets message or drawing under the dish. Notice how the message is disguised and difficult to see.

5

Slowly add water to the dish and watch in amazement as your message begins to appear!

How Does It Work

Jelly Marbles are tiny spheres that can absorb up to 300 times their weight in water.  These super absorbent polymers fill with water and are about 99% water when they are fully hydrated.  Because they are primarily made of water, light passes through them at almost the same speed that it passes through water.  When you add water to the dish, the light is refracted only a tiny bit when it hits the edge of each marble.  However, the index of refraction for both the marbles and water is so similar that the marbles become almost invisible, and the secret message below is revealed.