π₯ DIY Activity: Make a Periscope
Build Your Own Amazing Physics Project!
π€ Did You Know?
Periscopes are used in submarines to see above water while staying hidden underwater! You can make one at home using simple materials and the power of reflection!
π¬ Physics Concepts
Laws of Reflection: How light bounces off mirrors at equal angles
Mirror Positioning: Why 45° angles are perfect for periscopes
Light Path: How images travel through multiple reflections
π¦ Shopping List
- 2 small mirrors (pocket mirrors work great!)
- 1 empty cereal box or cardboard tube
- Scissors or craft knife
- Duct tape or strong adhesive tape
- Ruler and pencil
- Protractor (optional but helpful)
- Black paper or paint (optional)
⚠️ Safety First: Ask an adult to help with cutting. Handle mirrors carefully to avoid cuts!
1Prepare Your Box
What to do: Cut two rectangular holes on opposite sides of your cereal box - one at the top and one at the bottom. Make them about 2 inches wide and 1.5 inches tall.
Pro tip: The holes should be on the same side of the box, not opposite faces!
2Mark the Mirror Slots
What to do: Inside the box, mark diagonal lines at 45° angles where your mirrors will go. One mirror goes near the top hole, one near the bottom hole.
Remember: The mirrors must be at exactly 45° for the periscope to work properly!
3Cut Mirror Slots
What to do: Carefully cut thin slits along your 45° lines. These slits should be just wide enough to slide your mirrors in.
Adult help needed: Use a craft knife for clean, precise cuts.
4Install the Mirrors
What to do: Slide the mirrors into the slots at 45° angles. The reflective side of the top mirror should face DOWN and IN. The bottom mirror should face UP and IN.
Test it: Look through the bottom hole - you should see through the top hole!
5Secure Everything
What to do: Use tape to secure the mirrors in place. Make sure they can't move or fall out.
Optional: Paint the inside of the box black to reduce unwanted reflections.
6Test Your Periscope!
What to do: Hold the periscope vertically. Look through the bottom hole while pointing the top hole at something interesting. You should see the view from above!
Troubleshooting: If the image is dark or unclear, adjust the mirror angles.
π― The Science Behind It
Step 1: Light from an object enters the top hole
Step 2: It hits the first mirror at 45° and reflects down at 45°
Step 3: This reflected light hits the second mirror at 45°
Step 4: The second mirror reflects it horizontally to your eye!
Light Path Through Your Periscope
π️ Military Secret!
Real submarine periscopes can extend up to 60 feet above the submarine and have magnification lenses. Some modern ones even use cameras instead of mirrors!
π΅️ Spy Mission
Use your periscope to look around corners or over fences. Perfect for playing detective or hide-and-seek!
π Angle Testing
Try changing the mirror angles. What happens at 30°? 60°? Notice how only 45° gives you a straight view!
π Light Experiments
Try using colored lights or flashlights. See how different types of light behave in your periscope!
π Size Variations
Make a tiny periscope with a paper towel tube or a giant one with a big box. How does size affect the view?
❌ Can't See Anything?
Problem: Dark or no image
Solution: Check if mirrors are at exactly 45° and facing the right direction.
❌ Image is Sideways?
Problem: Rotated view
Solution: One mirror is probably facing the wrong way. Flip it around!
❌ Blurry or Double Images?
Problem: Multiple reflections
Solution: Paint the inside black or use better mirrors.
π― Level Up Your Periscope!
Add a magnifying glass: Tape a magnifying glass over one eyehole for zoom
Make it adjustable: Create rotating mirror mounts
Go horizontal: Build a periscope that looks around corners
Multiple mirrors: Try 3 or 4 mirrors for complex light paths!
π’ Where Are Periscopes Used?
Submarines: See above water while staying hidden
Tanks: Soldiers can look out safely
Medicine: Doctors use similar tools (endoscopes) to see inside bodies
Architecture: Daylighting systems bring sunlight into buildings
Photography: Taking pictures from unusual angles
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