Reflection and Absorption of Light
Students use a microcomputer connected to a light sensor and temperature probe to explore the reflection and absorption of radiation for different surfaces. Students follow instructions in this guided inquiry based lab and are then asked to design an experiment of their own to either test the reflectivity of sand, soils, water and other materials or to investigate the effect of different surface textures on reflectivity.
- Use a microcomputer interface to learn about reflection and absorption of light.
- Use a light sensor to measure the percent of incoming light that is reflected from a surface, i.e. the surface albedo.
- Use a temperature probe to measure the relative absorption of radiant energy for different surfaces.
Context for Use
This activity can be used as a lab activity in an introductory geoscience course that contains a discussion of absorption and reflection of radiation, e.g. Atmospheric Science, Climate, or Earth Systems approach. Instructors could also use aspects of this activity in an interactive lecture.
Description and Teaching Materials
This activity requires a microcomputer, multi-sensor interface, a light sensor and temperature probe.
The specific activity is included in "Earth Science with Computers" by Robyn Johnson, Gretchen Stahmer DeMoss, and Richard Sorensen published by Vernier Software (more info) , with a site license for $45.00. The complete activity in pdf format can be viewed at Reflection and Absorption of Light
The cost of the interface, temperature probe, and light sensor are $220, $29, and $45 respectively.
Students can also use a graphing calculator with the interface and sensors.
Comparable equipment can also be purchase from Pasco Scientific.
Teaching Notes and Tips
This activity will take approximately 2 hours to complete in a lab setting with some extra time possibly needed for students to summarize their reports. The activity description at Reflection and Absorption of Light
comes complete with two pages of Teacher Information. Doing parts or all of this activity in class as an interactive lecture is also an option.
The activity comes with very specific instructions and related questions. The Teacher Information section contains answers to most questions for easy assessment of student understanding. "Extension" ideas are also provided. Having students design their own experiment for an "Extension" investigation can also help you better assess their ability to synthesize what they have learned and apply it to a slightly different situation.
References and Resources
Vernier software has several other sample geoscience labs from Earth Science With Vernier
available in pdf format as examples at other examples
. These include "Comparing Sunscreens", "Where is North", and "Water Quality-TDS(Total Dissolved Solids)".
Pasco Scientific has about 13 online geoscience related lab activities available for free. These are mostly geared towards high school students but can easily be modified for an introductory college level course as either a laboratory activity, a special project, or an interactive lecture example.