Ready to be wowed and amazed by one of the easiest tricks on the planet?
This light refraction trick will make a coin disappear right in front of your eyes. It’s a good thing that this trick is so easy to do because you will want to repeat it over and over again to make sure you are not seeing things.
Don’t worry, the coin is nice and safe so you are not actually losing money from doing this experiment.
Let’s make some money disappear!
How to Do the Disappearing Penny Trick
- Clear glass
- Coin (we like to use pennies because they are easier to see)
- Place the coin underneath the glass.
- Have your child look at the coin from the side of the glass.
- Pour water into the glass until your child says he can no longer see the coin.
- Have your child look into the glass from the top. The coin that disappeared never moved!
How did your child react when the coin disappeared? My kids were dumbfounded that the coin disappeared as if the water dissolved it.
The best part was my husband walked in when the kids were reproducing the trick. Therefore, we performed the disappearing coin trick on him! My son poured the water while my daughter narrated the trick like how a magician would. Now you see it … now you don’t! And my husband was astonished too!
The biggest question that both my children and my husband asked was, “HOW?”
The Science Behind the Disappearing Coin Trick
Our eyes are light detectors. When the light goes through one medium, such as air, it experiences little or no refraction. In other words, the light travels in a straight line, bounces off objects, and reaches our eyes.
However, when the light travels through one medium to another, such as from air to water, it slows down and changes direction. The molecules in the air are spread out, so the light is able to pass through it easily. However, the molecules in the water are close together, and therefore light refraction occurs.
The water bends the light so much that the light bounces back into the glass. In the end, none of the light from the coin reaches your eyes, so the coin seems to have disappeared.
Final Thoughts on the Disappearing Coin in Water Trick
If you need something last minute to shock and entertain the kids, the disappearing coin trick is a good one to use. After the kids understand what is going on, they can repeat the trick over and over again for as many times as they like. Practicing pouring water into a glass is actually great for practicing their fine motor and practical life skills.
For more science magic tricks, check out: