WXMI — In our science experiment today, we look at a disappearing coin trick, which really is no trick at all. It illustrates density and refraction. Some things are more dense (or heavier) than other things. Water versus air, for example. That density can refract or bend light rays (among other things) and shape a number of things (or at least the way we see them).
A perfect example of this is the way we see rainbows. In a normal rainbow, sunlight hits raindrops falling, and those light rays are refracted or bent. They then become or turn into (like a prism) a rainbow. In much the same way, our coin trick works.
You'll need only a glass of water and any type of coin. Simply place the coin under an empty glass. Look through the glass. You can clearly see the coin. If you add water, the water is more dense than the air. Looking through the air and into the glass of water seems to make the coin disappear. Why? Similar to light rays being bent to form a rainbow, the light is bent as we peer into the water and appears to make the coin disappear. Of course, it really doesn't disappear. This trick or experiment is a good example of density and refraction.
The second and third graders were amazed! Try this one at home!