What Can Light Move Through?
August 4, 1999
Brief Description of the Lesson:
This lesson focuses on what objects and materials light may or may not pass through. In this lesson, students will experiment with different materials and will observe what materials do and do not allow light to pass through. Students will record their predictions and observations on a data chart and will also use creative drama to depict how light does or does not pass through transparent, translucent, and opaque materials.
This is science lesson that will allow students to manipulate materials in order to establish what materials light will and will not pass through.
This lesson would be appropriate for the first grade curriculum because students will demonstrate attitudes necessary for scientific investigation such as curiosity, readiness to learn from experiences, and willingness to postpone final judgment and will use the following science skills: observing, communicating, classifying, comparing, and predicting (according to the Alabama Course of Study for Science).
Light is a form of energy. There are many different sources for this form of energy. The sun is one form of this energy. The sun, which is a star, produces nearly all of the earth’s light. Very hot gases whirl around inside the sun and glow very brightly. This gives out (emits) light. All hot things give out light. Even humans emit invisible infrared lights. Other natural sources of light include lightning, fire, and the other stars. Some chemical reactions give out light. For example, fireflies and some deep-sea fish glow as the result of chemical reactions. Humans also create light. This light is known as artificial light and includes burning fuel in lamps and producing electricity for light bulbs.
Without light, it would be impossible to see! Our human eyes work just like cameras. The eye is shaped like a ball with a lens inside about the size of a pea. When looking at something, light enters through a small hole called the pupil. The pupil is in the iris, which is the colored part of the eye. The light passes through the lens and focuses onto a layer at the back of the eye called the retina. In the retina, there are light sensitive chemicals, which transform light into electrical messages. These messages are then passed on to the brain by the optic nerve. The brain decodes this message and finds out exactly what is being looked at and how far away it is.
When a ray of light hits an object, it may or may not pass through the object. Whether or not light passes through depends on the material used by the object. Transparent materials allow rays of light to pass through. A small amount of the striking light does reflect which enables us to see the position of the surface of the material. Examples include clear glass, clear plastic, and water. Some materials are translucent. These materials allow light to pass through but scatter the rays in all directions. Tissue paper and some types of glass are translucent. Opaque materials soak up (absorb) most of the light. A very tiny amount of light is reflected which allows us to see the object. Examples of opaque materials include wood and brick.
Materials and Equipment:
Have you ever wondered what type of materials and objects light can and cannot pass through? Have you ever wondered what an object needs to make a shadow? Today we are going to experiment with different materials. Like real scientists, we are going to make predictions, experiment, and then record our observations.
square pieces of aluminum foil, wax paper, clear plastic wrap, and cardboard. Each set should also have some type of book, a flashlight, and a data chart. Ask students to predict what materials they think light will and will not pass through. Record these predictions onto the data chart. Ask students to predict what materials might cast shadows – also record these predictions.
students should hold the materials and shine the flashlight directly at the material and note whether or not it allowed light to pass through and whether or not it created a shadow. Ask students to record their observations onto their data charts.
materials allowed light to pass through? Which materials did not allow light to pass through? Why do you think this is so? Why do you think some materials had shadows? NOTE: If at all possible, the teacher should allow these ideas to arise among the children’s own discussion.
volunteers to represent a transparent material (or a material that allows light to pass
through) such as a piece of clear glass. Then two additional students will represent
the light. Teacher will then ask four more volunteers to represent a translucent piece
of material such as a piece of wax paper and two additional students will dramatize
the light. In the last creative drama, the teacher will ask four students to represent an
opaque material such as a piece of cardboard. Two additional students will act the
part of the light. In the first drama, transparent students should allow the light to pass
through. In the second drama, translucent students should allow some light but not all
to pass through. In the third drama, opaque students should not allow any light to
down facts or ideas that children recall under the Learned section. If needed, mark out ideas the students listed under Know, but they have now disproved. Also, if necessary add more items under the Want section of the KWL chart.
Useful Internet Resources:
This is a great educational website for science. Although educational, children will find it enjoyable as it lists different games to play or different experiments to attempt. It also discusses optical modules with color and the artist Bob Miller’s "Light Walker".
Reflection of "What Can Light Move Through?" Science Lesson
My students thoroughly enjoyed this lesson, and I believe that they learned a lot from it also. However, at the beginning of the lesson, I thought that everything was going wrong and that they were not going to learn anything! To begin with, I had already placed the materials (aluminum squares, wax paper squares, cardboard squares and flashlights) on the students’ desks. This was a big mistake! The students were unable to pay attention to my directions because they were so intrigued with the different materials especially the flashlights! I asked the students to not touch and play with the flashlights. However, they are first graders and the idea of shining a flashlight straight into your teacher’s face is just too tempting! It took me a while to calm the students down enough for me to give directions. I had given each student a data chart (transparency copy is included with lesson plan). I tried to make the data chart as simple as possible. However, my students are not prepared to read and write legibly. Therefore, the date chart confused the entire class! I did, however, go over the prediction and data chart with my students on the overhead. I think this helped to clear up some of the confusion, but some students were still lost. However, although the students became very nervous and upset about having to fill in the data chart, I think most understood what they were being asked to predict and observe. They just did not want to write anything down. I have noticed in this class that they do not like to use inventive spelling – they want to be perfect! As I walked around the classroom trying to help students fill in their data charts, I would ask them "What do you think will happen when the light hits the clear plastic wrap?" Consistently, every student would tell me that they thought the light would pass through the material. However, I would then notice that this same student would not write down his/her predication. Also, because I had already passed out the materials, I caught some of the students "cheating" and testing out their predictions before they would attempt to write them down. From this, I definitely learned to wait to pass out materials until the teacher has finished going over the directions and etc. Or a teacher, to save time, could already have the materials out on the desk, but he/she would pull the students to a different area of the room to introduce the topic and to receive directions.
I allowed the students to experiment with the different materials and the flashlights. Once again, the students became so enthralled with the materials and the flashlights that most did not even bother to fill out the data chart. Most students began to immediately shine their flashlights on the ceiling, whirling them around in patterns or shining them on their partners. I was extremely disappointed, and I thought that my lesson was going to be a complete failure. I thought that they were not learning anything. Then, I heard one of the students ask his partner the question, "Do you think the flashlight is going through the ceiling?" And his partner replied, "I don’t think the light can go through the ceiling. Do you? Because then the light from the sun would be hitting us now." The students may not have been using the provided materials exactly as I had planned, but they were learning the desired concepts. Since, I had caught on to this conversation, I asked for the attention of all of my students. I asked did they think that the light from the flashlight could go through the ceiling. It became an impromptu experiment and helped to refocus the attention of the class back onto the lesson. Once the students experimented with the ceiling, they wanted to know what other materials light would and would not pass through. I noticed the noise level going down and the students began to experiment with the materials on their tables. After experimenting with these materials, some students asked (yes, actually raised their hand and asked) if they could experiment with other materials like their crayon boxes, their desks, and even themselves! My students were actually excited by the experiment and wanted to learn more. Therefore, within reason, I let my students experiment with different types of materials.
All of the sudden, my students were quietly discussing their findings. They did not want anyone else to hear what they had observed. However, one group (Group 1) was arguing that the light did shine through a book. Another group (Group 2) was disagreeing and saying that the light would not shine through the book. The group that said the light would not shine through the book asked the other group to come and watch their experiment. As expected, the light did not shine through the book. Group 1 then realized that they had been seeing the light from another group’s flashlight. Although, I believe that the students were getting the concepts, I still noticed that most were not filling out their data charts. They were very intimidated by these charts. As a result, I know the next that I teach this lesson, I will make the data chart easier by either using pictures or by allowing the students to place a check by an item if the light did or did not pass through.
After the students experimented, I called the students back to the colloquium (or the Big Circle as we called it in class). Before everyone even had the chance to sit down, a child said, "Ms. Keene, the light did not go through the cardboard, the aluminum foil, or the wax paper!" Immediately, another student countered, "It did too go through the waxy paper – just not a lot!" I did not even have to spur the kids into a discussion. They were very eager to share their findings. If a student said something the other students were very respectful and if they disagreed they said so. Many students disagreed about whether or not light would pass though the wax paper. One student suggested that we try it out. Another student said, "Can we turn out the lights so we can see if the light shines through?" We completed the experiment, and the students were able to conclude that a small amount of light would pass through the wax paper.
Before the lesson, I had discussed with my cooperating teacher, Ms. East, about introducing the words transparent, translucent, and opaque. We agreed that although the words were big words for first graders that they should still be introduced if the occasion arose. It was always a possibility that the students would catch onto the words. Therefore, during the Big Circle, when the occasion warranted it, I would introduce the words.
To assess my students, I asked for volunteers to participate in a creative drama. I decided to attempt to use the words of transparent, translucent, and opaque. For example, I asked one set of volunteers to act out how light would hit an opaque material. To my great surprise, the students who were acting out light would run towards the material and then run away! Due to the talking and distractions at the beginning of the lesson, I had thought my lesson was awful! However, I began to see that my students did understand the concepts I had listed in my lesson plan. Eventually, all students came to recognize that light would not pass through the aluminum foil and the cardboard, but bounced back from the cardboard. All students also recognized that the light easily passed through the clear plastic wrap and that the light only went through the wax paper a little.
To formally assess my students, I asked them to draw the three different situations for me – transparent, translucent, and opaque. It was amazing how well they understood the concepts. Many students had very detailed drawings showing how the light would or would not pass through. Most students even attempted to sound out words on their drawings. I believe that this occurred because they felt more confident in themselves due to the hands-on lesson. The students began to consider themselves as real scientists in their classroom.