Reversing Pic Illusion | Light Refraction Trick

This Water Refraction is a very easy science activity for kids to do at home and at school with household materials. Draw your own creative pattern and put it in front of a glass of water to have its reversed picture.

Age: 3+          Time: <5min

 Safety 

Adult supervision

 Materials List 

• Glass jar (any transparent cylindrical container)
• Water
• Dry erase board
• Marker

 Instruction 

Step 1/3 – Draw whatever you like on a white paper with a marker.

Step 2/3 – Put the dry erase board vertically on the ground and place the bottle in front of the dry erase board. The distance between the whiteboard and glass cup is different from glass jar to glass jar. You need to adjust the distance after you fill the glass with water.

Step 3/3 – Add water to the bottle and see the magic happens. 

 Troubleshooting 

1. Why can't I see the reversed picture?

— You need to adjust the distance between the dry erase board and the glass until you have a clear picture.

 Scientific Description 

In this case, the light travels from the image through the air, then through the glass cup into the water, and finally out of the water and into the air before it comes to our eyes. Every time the light passes from one medium into another, it refracts. As the light travels through a substance, the water in the glass jar, thick water in the middle and thin water along both rims, becomes concentrated into a focal point, acting as a magnifying glass that bends the light toward the center. The light focuses together at the focal point and beyond the focal point, the image is reversed because the light that stays on the right is now on the left, the left on the right.

 Extensions 

Can you create a serial show in front of the glass jar?