Why Can a Periscope Let You See Over a Wall?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why can a periscope let you see over a wall?

The Big Idea

A periscope uses two mirrors set at a slant to pass light around an obstacle. Light from the scene goes down the tube and into your eye. That lets you see over a wall without lifting your head.

Top Mirror

Step one: the top mirror. It sits above the wall and catches light from the scene beyond. Then it turns that light and sends it down the tube.

Bottom Mirror

Step two: the bottom mirror. The second mirror faces your eye and turns the light once more. Now the light travels straight into your eye.

Slanted Mirrors

Step three: the slant. Each mirror is tilted at 45 degrees, which is half of a right angle. That tilt turns the light a perfect quarter turn each time.

A Closer Look

Let's take a closer look! Light starts from things on the other side of the wall. The top mirror catches it. The tube holds it on the path. The bottom mirror sends it to your eye.

Quick Facts

Quick facts! Submarines use periscopes to look above the waves. Soldiers in trenches used them long ago to peek out safely. Periscopes work because light bounces off mirrors at matching angles. Build one with a grown-up.

Think Like a Scientist

Now, think like a scientist! With a grown-up, build a periscope from a milk carton or a long box. Tape two small flat plastic mirrors inside, tilted at 45 degrees. Look over a table's edge to see what is behind it. Ask your grown-up to cut the carton.

Outro

A periscope bends light around a wall with two mirrors. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!