Weird Science: Refractive Index

HONOLULU (HawaiiNewsNow) - It's time for another weird science experiment with Dr. V. This morning, he's going to show us what happens when we add water-storing gel beads to a warm bowl of water. Try it out!

Dr. V Show:  Refractive Index

Things you will need:

  • Water-storing Gel beads
  • Large Bowl
  • Clear glass bowl or plate
  • A picture
  • Water

The Experiment:

Place the gel beads into a large bowl and pour 2-3 quarts of warm water (Follow the instructions that come with the gel bead) in the bowl (warm water helps speed up the absorption process).  Allow the beads to sit for up to six hours but over night works even better. Place the glass bowl or plate on top of your picture.  Put a layer of the gel beads in the clear glass bowl. What happens to the picture? Are you able to see your picture clearly?  Then slowly pour water in the glass bowl to submerge the gel beads. What do you see now?

How does it work?

These gel beads are made up of a superabsorbent polymer that absorbs 300 times its normal weight in water.  These marbles are about 99% water and the only reason that you can see them is for the edges of the sphere. The light that passes through the water only reflects off the edges of the spheres. The reason they seem invisible is they have the same index of refraction as water. That means they bend light in the same way that water does, so it looks like they disappear. Try to keep them clean and free from oils and dirt. The more that you touch them, the easier it will be to see them because the dirt reflects off the surface of the marble.

Copyright 2010 Hawaii News Now. All rights reserved.