Impress your friends and family with this magic reveal trick, as they watch a toy appear before their eyes! Preparation: 24 hours in advance  

You Will Need:

• Water beads, available from toy shops or online
• Jug of water
• Large jar, small vase or similar clear glass container
• Small toy, such as a Lego figure
• Optional: coloured torch, fairy lights or led lights

 

Method:

• Follow the instructions on the packet to soak your water beads 24 hours before you do this experiment
• Place the water beads in the clear jar, filling it about two-thirds of the way up.
• Carefully ‘hide’ your toy in the middle of the water beads. You should be able to see the colours of the toy, but not the toy itself
• Slowly pour water into the container. The image of the toy should begin to appear from the bottom up!

Optional: before pouring in the water, shine coloured light through the water beads and watch it form crescents of light in each bead. Change the direction of the light to change the intensity and effect. Safety: do not place lights in the water; shine them from the outside of the jar only.

The Science Bit:

  Light travels in straight lines, but different substances will bend that line, causing the light to change direction. This bending of the light wave is known as refraction. In this experiment you begin with a mixture of water (water beads) and air (the gaps between the beads). The light travels through the air in one direction, but through each bead in another, scrambling the image so you can’t see it clearly. When you add water, this fills the spaces between the beads. Once you’re left with only water in the jar, the light can travel in a straight line towards your eyes, so you can see the toy clearly! Optional: the same thing will happen with the coloured lights, which will scramble to begin with, but be revealed clearly when you add water to the jar. Remember to keep your lights on the outside of the jar.