Science Experiments about Light for Kids

Science experiments are a fun way for kids to learn about cool scientific principles without getting bored. In this article, I’ll detail a few science experiments that are easy, entertaining, and teach your child all about the wonders of light and refraction.

Experiment 1. The Incredible Shrinking Spoon:

What you’ll need:
A bucket or large bowl

Step One: Fill a bucket, or large bowl, with water. Make sure that there is enough water to reach the top of the container.
Step Two: Hold a spoon by the handle and dip it into the water until only about an inch of the spoon handle is above the water. The spoon will appear to magically shorten!

Why does it work?
The light rays do not travel back to your eyes in a straight line as they reflect off of the underwater spoon. Since the reflected light rays bend at the surface of the water, the top of the spoon seems higher up than it actually is. This is why the spoon seems to shorten underwater, and also why water typically appears shallower than it actually is – it’s all about light refraction!

Experiment 2. See Through Your Hand:

What you’ll need:
A piece of paper (I like to use a piece of printer/copier paper)
Your hand (Not much required for this experiment!)

Step One: Roll a piece of paper into a tube.
Step Two: Hold the paper tube up to your right eye, like a telescope.
Step Three: Now, hold your open hand in front of your left eye. Look forward with both eyes and you’ll notice something amazing – your hand will appear to have a round window right through its middle!

Why does it work?
The right eye is looking into the paper tube, while the left eye is looking at your left hand. Then, the eyes do what they normally do and create a composite image in your brain of both views combined. The image from inside the paper tube (the hole) is combined with the image of your palm, making the hole appear to be in the center of your hand.

Experiment 3. The Disappearing Coin:

What you’ll need:
A glass jar with a lid
1 coin

Step One: Place the coin in the jar.
Step Two: Fill the jar with water, then put the lid on the jar. Like magic the coin will seem to disappear!

Why does it work?
When the jar doesn’t have water in it, the light rays travel normally back to our eyes, and the coin is completely visible. However, when the jar is filled with water, the light rays hit the water from below at an angle and reflect back on the bottom of the glass. When this bouncing light ray trick happens, the coin seems to vanish!

Experiment 4. The Breaking Pencil:

What you’ll need:
A glass
1 Pencil
A spoon or ladle

Step One: Fill the glass halfway with very salty water.
Step Two: Slowly fill the rest of the glass with water from the tap. Be careful not to agitate the salty water too much. This works best if you slowly pour the tap water over the back of a spoon or into a ladle so that the tap water is gently dispersed, and doesn’t mix into the salty water.
Step Three: Lower the pencil into the glass, and be amazed as the pencil seems to break into three parts!

Why does it work?
The light rays have three different angles of refraction. The light rays above water level are normal, and show the pencil exactly as it is. The light rays from the submerged pencil (tap water level) get bent as the pencil emerges from the tap water level into the air. Then the pencil “breaks” again as it enters the salty water level. This is because the optical density of the salty water changes the light refraction even more than would happen in the tap water. The result of these three different light refraction types is a pencil that seems to be staggered into the separate pieces.