Why Does a Sheet of Paper Glow When You Hold a Flashlight Behind It?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why does a sheet of paper glow when you hold a flashlight behind it?

The Big Idea

Paper is made of tiny fibers with air gaps between them. Light going in bounces around among the fibers and spreads out, and some of it comes out the other side. The paper glows softly, but it does not show a picture.

Tiny Fibers

Step one: tiny fibers. Paper is made from wood fibers pressed into a thin sheet. There are little gaps of air between the fibers, and light cannot go straight through them.

Light Bounces

Step two: light bounces. Light from the flashlight hits the fibers and bounces in all directions, again and again. Some bounces back, and some zigzags all the way through.

Soft Glow

Step three: a soft glow. The light comes out in every direction, so the paper glows evenly. Scientists call a material like this translucent.

A Closer Look

Let's take a closer look! Shine a flashlight behind the paper. The sheet glows softly, like a night-light. Cut-out shapes in a second paper change how the glow looks. Lanterns use paper to make a gentle light.

Quick Facts

Quick facts! Lanterns and lampshades often use paper to make a soft glow. Thicker paper glows less, because less light gets through. Thin tissue paper glows brightly, because it has fewer fibers to stop the light. Keep paper away from hot bulbs.

Think Like a Scientist

Now, think like a scientist! In a dark room, shine a flashlight behind a sheet of white paper. Cut simple shapes out of a second paper. See how the glow changes. Keep paper away from hot bulbs.

Outro

Paper scatters light into a soft glow. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!