Light
Background Information & Activities

© 1999-2012 BrainPOP. All rights reserved.

What do many living things need to survive? Most plants and animals rely on food, water, shelter, and light in some way. In this movie, children will learn about an energy that is all around us and helps us see the world: light! But what is light? Remind children that light is a type of energy, like heat or sound. The Sun, stars, lightning, and fire are all natural sources of light. Living things need light to survive, including plants, animals, and people. People use electricity to light their homes and some use solar power, which converts sunlight into electricity. Light is made up of tiny particles that travel in waves. Light travels until it hits an object and is either absorbed or reflected. We can see because light is reflected from an object to our eyes. Light can pass through transparent, or clear objects, but not through opaque ones. Objects that block light can cast shadows. Colored glass objects block some light but also allow some light to pass through, while translucent objects, like frosted glass or wax paper, diffuse light and prevent clear vision of whatever is on the other side.

Many living things rely on light to survive. Plants convert sunlight into food via photosynthesis to grow and change. Cold-blooded animals such as reptiles, amphibians, and insects rely on light to warm their bodies. People need light to grow crops, but they also need light to see. People use electricity to power their light bulbs and light their homes. Many buildings and electronics use solar power, a renewable energy resource which uses special devices that convert sunlight into electricity.

Remind children that light moves very, very quickly—at 186,282 miles per second, or 299,792,458 meters per second. Light rays travel in one direction until they hit an object. Light reflects, or bounces off the object and into our eyes so we can see it. The object also absorbs, or takes in, some light. Objects that are shiny, such as metal pots and mirrors, reflect light better than dull objects such as dark sweaters or fuzzy toys, which absorb more light. Smooth, flat mirrors reflect light in roughly the same angle the light hits them so we can see reflections. When light hits curvy mirrors, it bounces off in many different directions and back to our eye. We see our reflections, but they are distorted.

Light can easily pass through some objects, such as clear plastic or glass. These objects are transparent and we can see through them. Light cannot pass through opaque objects, such as wood blocks. Objects that block light can cast shadows. Show children that when an object blocks light, light cannot pass through to the other side. You see a dark spot that’s shaped like the object—a shadow. This is how we know that light travels in straight lines; if it curved, it would bend around opaque objects and shadows would not be made. Some objects block some light but also allow some light to pass through. Sunglasses and stained glass block some light. Translucent objects diffuse light in many different directions. It is difficult to see through translucent objects such as sheer fabric, wax paper, frosted glass, or tissue paper.

When light passes through objects, it refracts, or changes direction. Place a spoon in a clear glass of water. What happens? The spoon looks like it’s broken. When light travels through water or glass, it slows down and changes directions or “bends.” Then as it passes through to air, it speeds up again. This changes the way we see the object. Binoculars, telescopes, microscopes, and magnifying glasses all refract light in different ways so we can see things in closer detail.

Light is a complex and fascinating subject that children can explore all on their own. We recommend completing the features that go along with the movie, as well as using or adapting the lesson ideas below to reinforce the material. For further background information, we recommend watching BrainPOP’s See more lesson plans and resources: BrainPOP Educators.

Light Teacher Activities

© 1999-2012 BrainPOP. All rights reserved.

Shadow Shapes

Ask your students to work in pairs, and have them collect small objects around the classroom. Then give each pair a flashlight and turn off the lights in the classroom. Have one student place an object in front of the flashlight and have the other student guess the object that made the shadow. What clues did he or she use to find the answer? Encourage students to write their thoughts and ideas down in their notebooks. Then have pairs experiment using the flashlight to change the shape of the shadow. How can you make the shadow bigger? How can you make the shadow smaller? Do some objects create a darker shadow, and some a lighter one? Why would that happen? Discuss results with the entire class.

Beaming Light

For this activity you will need several flashlights, tin foil, small mirrors, and a few small objects. You may want to ask students to bring a flashlight from home or ask parents to lend their flashlights to the class for a few days. Cover the front of each flashlight with tin foil and poke a small hole in the center. Then divide your class into partners or groups and give each group a full set of materials. Turn off the classroom lights and ask students to shine their lights onto the mirrors. What happens? What happens when they move their mirrors around? Then ask them to place their objects in different locations around the classroom and try to “hit” their object with their light beam. You may also want to challenge them to “hit” other items in the classroom: charts, the clock, speakers, etc. After, allow time for students discuss what they have learned about light and how it travels.

Shadow Puppets

To connect reading and writing to science, have your students make shadow puppets by cutting different shapes or animals out of black or opaque construction paper. Students can then tape or glue craft sticks or pencils to their cutouts to make puppets easier to hold. Have students write a story using their shadow puppets. Then use a flashlight or a camping lantern so students can cast their shadows to tell and act out their stories.

Light Family Activities

© 1999-2012 BrainPOP. All rights reserved.

Reflection

Together with your child, look for your reflections in different objects in your home. You can find your reflection in tea kettles, pots and pans, mirrors, and metal pipes and tools. If you take a walk, your child will see his or her reflection in car doors, and in shop windows. Remind your child that when a light hits a smooth, flat object like a mirror, it bounces back in roughly the same direction. When light hits a bumpy object, it bounces back in different directions. As a result you see a distorted or “funny” reflection. Experiment looking at your reflection in different surfaces and feel free to make funny faces!

Passing Through

Remind your child that light can pass through some objects, but can’t pass through others. Some objects block some light and let some light through. Gather different objects and have your child predict if the object is opaque, transparent, or translucent. Choose a variety of objects such as wooden blocks, a glass, or tissue paper. Then use a flashlight to shine on the object to test your child’s predictions.

Can You Grab It?

Collect a bunch of small objects of different shapes and sizes. Then fill a few big glass bowls or wide glass vases with water. Drop the objects into the containers. Challenge you child to grab the objects while looking at the bowl from above, and then from the side. Discuss how light refracts and bends when it passes from air to water, so this challenge might be trickier than your child expects because the objects may look like they are in a different location, or even as if they are broken.