To illustrate how the use of scientific inquiry can solve different kinds of problems, like blocking unwanted sunlight.
This lesson was developed by the Challenger Center as part of NASA's MESSENGER Mission, of which Science NetLinks is a partner.
The aim of this lesson is to illustrate how scientific inquiry can be used to solve different kinds of problems. For example, by studying ancient solutions to the problem of excessive sunlight on human vision, we can better understand the process of designing the solar panels on the MESSENGER spacecraft. As part of this lesson, students will build snow goggles similar to those used by the Inuit peoples. The goggles are meant to block unwanted light, while increasing the viewer's ability to see in a bright region. Students also will create their own version of the goggles to improve upon existing designs. Students will then compare the process used to invent snow goggles with that employed by MESSENGER designers. In doing so, they will discover that even though exact solutions to the problem of excess sunlight may be different, the basic principles of scientific inquiry for solving problems are the same. Refer to the Science Overview section of the lesson for a summary of the science content relevant to the activities in the lesson. Refer to the Lesson Overview for a more detailed explanation of what students will learn from the lesson.
Research shows that some middle-school students who have not received any systematic instruction about light tend to identify light with its source (e.g., light is in the bulb) or its effects (e.g., patch of light). They do not have a notion of light as something that travels from one place to another. As a result, these students have difficulties explaining the direction and formation of shadows, and the reflection of light by objects. Middle-school students often accept that mirrors reflect light but, at least in some situations, reject the idea that ordinary objects reflect light. Many middle-school students do not believe that their eyes receive light when they look at an object. Students' conceptions of vision vary from the notion that light fills space ("the room is full of light") and the eye "sees" without anything linking it to the object to the idea that light illuminates surfaces that we can see by the action of our eyes on them. The conception that the eye sees without anything linking it to the object persists after traditional instruction in optics; however, some fifth-graders can understand seeing as "detecting" reflected light after specially designed instruction. (Benchmarks for Science Literacy, pp. 338-339.)
As students assemble their snow goggle models, keep in mind that middle-school students typically think of models as physical copies of reality, not as conceptual representations. They lack the notion that the usefulness of a model can be tested by comparing its implications to actual observations. Students know models can be changed but changing a model for them means replacing a part that was made wrong. (Benchmarks for Science Literacy, p. 357.)
Note: Parts of this lesson were extracted from the unit, Staying Cool
Conduct the brainstorming activities listed in the Warm-Up and Pre-Assessment section of the Lesson Plan, which will help to draw students' attention to the problem of excess sunlight and how it can cause blinding conditions that make it difficult or impossible to see well. Keep in mind that as students identify a shared "problem" between the categories of Sun, Sunglasses, and Hunters, they will be asked later in the lesson to identify similar problems between the Sun, Artic Hunters, and the MESSENGER mission itself.
In the Procedures section of the Lesson Plan, help students see that they have completed step one of the process by identifying and "stating a problem." After reviewing and discussing each of the five key steps in the process, students will be expected to use it against the problem that plagued many Inuit hunters in the sunny artic during the 19th century—how to get rid of excess light in order to clearly see and spear seals that were needed for survival.
In groups of three, students will then proceed to apply the remaining four steps to the old, blinding Inuit problem. The Field-of-View (FOV) With and Without Snow Goggles student sheet will be needed to help guide each group in assembling, testing, and experimenting with their snow goggles. When finished, have each group answer the questions on their worksheets. An Answer Key has been provided.
When finished, regroup the class and have them discuss their observations as part of the Discussion and Reflection phase of the Lesson Plan. As part of this process, help students come to the general conclusion that their goggles reduce the amount of light shining in their eyes. For those students who wish to calculate how much light is reduced by their goggles, they can complete the Field-of-Vision (FOV) With Math student challenge sheet at the end of the lesson.
As noted in the Discussion and Reflection section, you may wish to assign as homework or continue in a second class period the activity involving the MESSENGER Information Sheet, where students identify similar problems between the MESSENGER mission and the artic hunter. The Scientific Method in Action student challenge sheet, which considers the problem of how MESSENGER can deal with excess sunlight while traveling to Mercury, may also be assigned as homework or extra credit.
Determine whether or not students' observations about the effectiveness of reducing light to the eye can actually improve vision or if it has any other side effects. Use the Field-of-Vision (FOV) With and Without Snow Goggles student sheet to evaluate the level of precision in conducting experiments. Revisit and discuss what they learned from the activity involving the transfer of knowledge to the MESSENGER mission.
A number of suggested essay questions for tests or take-home tests can be found in the Assessment section of the Lesson Plan.
Finally, summarize the lesson by reviewing and reinforcing the key points highlighted in the Closing Discussion section.
To extend the ideas in this lesson, you might want to try one or more of these other Science NetLinks lessons:
- Light 1: Making Light of Science
- Light 2: The Lighter Side of Color
- Light 3: All Those Seeing Color, Say Eye!
- Cells 1: Make a Model Cell
- Models of the Water Cycle
Challenge students to design a better pair of goggles. For example, they may want an extra foldable visor for changing light conditions or to serve as multipurpose goggles that may also protect against UV radiation, wind, glare, etc.