This DIY periscope experiment helps students understand how light works by giving them something they can actually use. Some science concepts make more sense when students can interact with them directly. With Science Unlocked® full-year curriculum, they build tools that let them see those ideas play out in real time.
This experiment from the A-Maze-ing Mirrors kit gives students a way to explore how light reflects and travels, using simple materials and a build they can test right away.
What You’ll Need
From the kit:
- Mirrors (2)
- Tape
- The box the kit came in
Other items:
- Scissors
- Marker or pen
Instructions
- With adult help, cut the two long top flaps off the box.
- Draw a straight line down the middle of each piece of cardboard.
- Then, cut each piece in half to create four long strips.
- Cut about 2 inches off the end of two pieces, so you have two long pieces and two shorter ones.
- Label the short pieces A and C, and the long pieces B and D. Write the letters on both sides.
- Arrange the pieces in order: A, B, C, D. Adjust them so that A opens at the top, and C opens at the bottom.
- Tape the edges together to form a tall rectangular shape.
- Fold and secure the sides to create a box with no top or bottom. Tape the edges so it holds its shape.
- Draw a line across A, B, and D near the top opening.
- Draw another line across C, A, and B near the bottom opening.
- With help, cut along both lines to create openings for the mirrors.
- Slide one mirror into the bottom opening at an angle, halfway between pointing forward and downward.
- Place the second mirror into the top opening at the same angle but facing the opposite direction.
- Tape the mirrors in place so they do not move.
- Check that both mirrors match angles. Adjust if needed.
- Cover the outside if you want and decorate your periscope.
Seeing the Unexpected
Hold the periscope with the top opening facing outward and look through the bottom.
You’ll see something unexpected! You’re able to look over or around objects without moving your position. That happens because light is bouncing from one mirror to the other before reaching your eyes.
Following the Path of Light
Light travels in straight lines, but when it hits a mirror, it reflects. In the periscope, the first mirror redirects the light downward. The second mirror redirects it again, so it reaches your eyes.
The angles matter. If the mirrors are not aligned, the light won’t travel correctly, and the image disappears. That’s why adjusting the mirrors is part of the learning.
Try This Next
Once the periscope is working, test it in different situations:
- Look over a fence or table
- Try to see around a corner
- Compare what you see with and without the periscope
These small tests help students connect what they built to how light behaves in the real world.
What They’ll Notice Right Away
The DIY periscope experiment gives students a result they can immediately use because they’re observing and interacting with the concept.
Seeing light change direction makes reflection easier to understand than reading about it. The build, adjustments, and final results all work together to make the idea clear.
Within Science Unlocked, this activity connects to other lessons that explore how light behaves and how observation works in science. Instead of being a one-time build, it becomes part of a sequence that helps students recognize patterns and apply what they’ve learned in new ways.
