Build Simple Periscope for Light

When you think of a periscope, you might picture a submarine’s eye‑hole or a child’s toy. Yet, a periscope is a straightforward optical device that demonstrates the fundamental principle of light reflection. By constructing a Simple Periscope, you can explore how mirrors redirect light, observe angles of incidence and reflection, and gain hands‑on insight into basic optics. This guide walks you through the materials, steps, and science behind building a functional periscope that is both educational and fun.

Materials and Tools You’ll Need

Gathering the right components is essential for a clear, reliable reflection. The following list covers everything you’ll need to assemble a Simple Periscope that works for classroom demonstrations or personal experiments.

Two small, flat mirrors (45° angle, 2–3 inches in size)
Cardboard or a sturdy plastic tube (about 12 inches long)
Adhesive tape or glue (double‑sided tape works best for mirrors)
Scissors or a utility knife
Ruler and pencil for measurements
Optional: a small flashlight or a bright light source for testing

Step‑by‑Step Construction Guide

Follow these steps to build a Simple Periscope that accurately reflects light and demonstrates the law of reflection.

Prepare the Tube: Cut the cardboard or plastic tube to a length of 12 inches. Ensure the ends are smooth and straight to avoid light scattering.
Mark Mirror Positions: Measure 3 inches from each end of the tube. Mark the spots where the mirrors will be attached. The mirrors should be positioned so that the angle between them is 90°, creating a right‑angle path for light.
Attach the First Mirror: Using double‑sided tape, secure the first mirror at the 3‑inch mark on the inside of the tube. The mirror’s reflective side should face toward the center of the tube.
Attach the Second Mirror: Repeat the process for the second mirror at the opposite end. The reflective side should also face toward the center.
Seal the Ends: Tape or glue the ends of the tube to prevent light from leaking around the mirrors.
Test the Periscope: Point the periscope at a bright light source and look through the opposite end. You should see a clear reflection of the light source, confirming that the mirrors are correctly aligned.

Understanding Light Reflection in Your Periscope

The Simple Periscope relies on the fundamental principle that light reflects off a surface at an angle equal to the angle of incidence. When you look through the periscope, the first mirror redirects the incoming light 90° toward the second mirror, which then sends it straight to your eye. This process demonstrates the law of reflection and shows how mirrors can be used to change the direction of light without altering its speed.

By adjusting the angle of the mirrors slightly, you can observe how the reflected image shifts. This hands‑on experiment reinforces concepts such as:

Angle of incidence equals angle of reflection
Mirror orientation determines image direction
Optical path length and its effect on image clarity

Applications and Extensions of the Simple Periscope

Beyond a basic demonstration, the Simple Periscope can be adapted for various educational and practical uses:

Field Observation: Use a periscope to view objects that are otherwise out of sight, such as a distant building or a hidden corner of a classroom.
Optics Lab Experiments: Combine the periscope with lenses to study refraction, or replace the mirrors with prisms to explore dispersion.
Art and Design: Create a periscope-inspired installation that plays with light and reflection for visual effect.
Engineering Projects: Use the periscope as a starting point for designing more complex optical instruments like binoculars or telescopes.

Safety Tips for Working with Mirrors and Light

While building a Simple Periscope is generally safe, it’s important to follow these precautions to protect your eyes and ensure a successful experiment:

Never look directly into a bright light source or a laser beam.
Use mirrors with a matte finish to reduce glare.
Secure all components firmly to prevent accidental dislodging.
Keep the periscope away from children who might misuse it as a toy.

Conclusion: Light Reflection Made Simple

Building a Simple Periscope is an engaging way to bring the abstract concepts of light reflection and optics into tangible form. By following the steps above, you’ll create a device that not only works but also serves as a springboard for deeper exploration into the physics of light. Whether you’re a teacher, a student, or a curious hobbyist, this project offers a clear, hands‑on demonstration of how mirrors can redirect light and reveal the hidden pathways of our visual world.

Ready to explore the world of optics? Grab your mirrors, cut your tube, and start building your Simple Periscope today. Share your results and inspire others to discover the science behind light reflection!

Frequently Asked Questions

Q1. What materials do I need to build a Simple Periscope?

You’ll need two small flat mirrors (45° angle, 2–3 inches), a 12‑inch cardboard or plastic tube, double‑sided tape or glue, scissors or a utility knife, a ruler, and a pencil for measurements. Optional items include a flashlight or bright light source for testing. These materials are inexpensive and easy to source from craft stores or online retailers.

Q2. How do I ensure the mirrors are correctly aligned?

Mark 3‑inch spots from each end of the tube. Attach the first mirror at the front mark with the reflective side facing the center, then attach the second mirror at the rear mark similarly. The mirrors should form a 90° angle, redirecting light from one end to the other. Test by pointing the periscope at a bright light and looking through the opposite end.

Q3. Can I use a longer tube for a better view?

Yes, a longer tube can increase the optical path length, but it may also introduce more light loss and require more precise alignment. Keep the tube’s interior smooth and seal the ends to minimize scattering. For classroom demonstrations, 12 inches is a good balance between size and clarity.

Q4. What safety precautions should I follow when working with mirrors and light?

Avoid looking directly into bright light sources or lasers. Use matte‑finished mirrors to reduce glare, secure all components firmly, and keep the periscope away from children who might misuse it. Always test the device in a well‑lit area to prevent accidental eye exposure.

Q5. How can I extend the Simple Periscope for more advanced experiments?

Combine the periscope with lenses to study refraction, replace mirrors with prisms to explore dispersion, or use it as a foundation for building binoculars or telescopes. You can also create art installations that play with light and reflection, or adapt the design for field observation of distant objects.