Have you ever looked at a rainbow and wonder how that happens? Most of us know that it takes a special combination of rain and light before a rainbow appears. Why a rainbow appears is due to the bending of light waves when they pass through water droplets. This process is known as refraction. A fun way to create rainbows without water is by using prisms. Prisms bend light waves and disperse the light into individual colors. Each color has a different wavelength and shows up at a slightly different angle.
Isaac Newton performed the first experiments using glass prisms to reveal the individual colors contained in white light. You can also use prisms made from other clear materials, including gelatin! The following resources contain more information along with fun light facts, videos, and experiments you can use to have fun bending light.
Light Waves and Color: This site has a series of lessons on light waves and color. The three lessons include why light is considered a wave, how light is seen, and the pathways of light. Also found in this site are further lessons using prisms and exploring light wave lengths.
Light, Prisms, and the Rainbow Connection: How is a rainbow made? This page explains the relationship between light and water droplets acting as a prism. Suggested student activities allow students to explore the connection between light and rainbows using prisms.
Bending Light Exploration Lab: This lab helps students explore how light bends through different materials. This page includes a PDF worksheet.
White Light: Prism: On this Britannica Kids page is a simple definition of of prism along with a colored illustration of white light passing through a prism.
Bending Light with Refraction: Physics for Kids explains that all lenses refract light. Examples include reading glasses, telescopes, and prisms. Additional links on this page will provide additional resources.
Refraction, Lenses, and Prisms (PDF): This is a PDF worksheet providing study material and questions on the topic of refraction using lenses and prisms.
Visible light Through a Prism: Here is an illustration of how a white light is refracted through a prism and shows individual colors dispersed according to their wavelength.
Rainbows and Spectras: On this educational website, you will find several lessons on rainbows, light, and spectra complete with teacher's pages for lesson planning.
Prisms and Colour: This resource page from the UK presents good illustrations and examples of the ways a prism disperses light. Included on the page are links to some animated resources.
Reflection and Refraction (PDF): How is light bent? How do reflections occur? These are some of the questions answered in this PDF chapter. Includes a physics lab session for bending light.
Rainbows: A lesson on rainbows complete with questions to consider, review questions, and suggested activities.
Bending Light Rays (PDF): This is a PDF sheet with instructions for setting up an experiment to bend light rays using prisms and includes a guideline for making notes of observations.
Create Your Own Rainbow: No prism? No rain? No problem. This experiment shows how to create your own rainbow using a pan of water, a mirror, white paper, and flashlight.
Bending Beams of Light: With background for teachers, a materials list, and activity guides, this page offers some great resources for learning about light!
Prism Lab of a Different Sort! This lab setup includes instructions for making gelatin prisms.
Rainbows, Halos and Coronas: Here is a great explanation of what it takes to see a rainbow and how rainbows, halos, and coronas are best observed.
Lights and Prisms: This page shows a re-creation of Newton's experiment that used a triangular prism to split light in colors.
All the Colors of the Rainbow: The video on this page shows a Newton color wheel that turns white when in motion but as it slows, the colors reappear.
Light Bent the Wrong Way: This brief article explains new experimentation to bend light the "wrong way" to, in theory, design a cloaking device. It's not yet possible, but it could be a source for interesting class discussions.
Light (video): A children's video explaining light waves and how they are seen. Includes review questions and a vocabulary list. More videos about light refraction can be found on this page as well.
Facts of Light (PDF): This PDF lessons on light and light refraction and is appropriate for elementary school students.
Gel-Optics (PDF): A complete lesson guide including materials list and objectives using gelatin prisms to study light.
Light and Color (video): PBS Kids discuss "painting" with light and making a sculpture from old CDs and shining light on the disks to reflect colors onto surrounding walls.
How Do Rainbows Form? In additions to answering the question, this site has a video showing a huge double rainbow and explains how it was formed.
How Do Prisms Work? To answer this question, this article discusses prism shapes and materials as well as light refraction and internal reflection.
Light & Color: Light Dispersion: This PBS-sponsored video explains Newton's investigation of light.
Where Does Color Come From? (PDF): This document contains lesson material for exploring light and how we see it under different conditions.
Dialogue for Kids: What is Light? Part of Idaho Public Television programing, this site discusses visible light, wavelengths, and color.
Physics for Kids: The Science of Light: Do you know why light goes through some things and not others or what it is made of? This site answers those questions and more while encouraging kids to explore the science of light.