Young Space Explorers Breaking Light Activity

INTRODUCTION:

This activity is one of several designed to explore some of the properties of light.

Light is very important in our lives. We need it to see. The light from the Sun also provides warmth and allows plants to grow. Light is also very important in studying the objects in the night sky. We can't visit the stars, but we can use their light to study them.

MATERIALS:

You will need:

1. a pair of "rainbow glasses"

2. a lamp (incadescent light) with the lampshade removed

3. other sources of light (candles, bulbs, etc.)

INSTRUCTIONS:

INSIDE

1. Turn on the lamp. This activity works best if the light is small in size (like a lightbulb with no lampshade), the room is dark, and you stand some distance away. Note that the light looks fairly white, with no particular color.

2. Now look at the light with your rainbow glasses. What do you see? The light has been broken into all its various colors. Notice that they are always in the same order: purple, blue, green, yellow, orange, and red, the same colors as the rainbow. Purple will always be closest to the light and red the farthest from the light.

3. Repeat this, using anything that glows. Here are some ideas:

• Various household light and lamps
• Flashlights
• Candles (careful!)
• Gas flame or hot electric burner on the stove (careful!)
• Fire in the fireplace (careful!)
• Sunlight reflecting off something shiny inside or outside a window (like a car bumper). Don't look at the Sun directly, it is too bright and can burn your eyes!

1. At night there are lots of neat things to look at with your glasses! You will see the same rainbows of color that you saw looking at the lamp.

• Moon - this is sunlight reflected off the Moon's surface (safe to look at)
• Venus - the bright "star" (actually a planet of course) (its rainbow will be faint so do this away from other lights)
• Car lights - white headlights and red tail lights
• Illuminated store signs

2. Some things give off different colors of light because of what they are made of. When you look at their rainbows with your glasses, you will see that the colors don't look the same brightness. The rainbow may look like bright beads of different colors.

• Street light - sodium type (orange colored light). Note that the rainbow has only certain colors in it - that is the special rainbow of sodium.
• Street light - mercury type (white light). Note that the rainbow has only certain colors in it - that is the special rainbow of mercury.
• Neon signs at stores. These are cool - they also glow only in certain colors, like bright beads of color (the special rainbow of neon)! Neon signs are made with thin tubes and are usually red, blue, or green. Many stores hang them in their windows. In my town, lots of stores have neon signs that say "OPEN".

These are the colors of Neon!

THINGS TO THINK ABOUT:

1. You can see a rainbow without using your "rainbow glasses". So something must break the sunlight apart into the rainbow. Do you know what it is that is doing this?

2. Almost everything that glows with light is hot (the Sun, light bulbs, candle flames). It is possible that being hot has something to do with making light?