Discovery of Infrared Light

Teacher Frequently Asked Questions

Who is the target audience for this activity?

Grades 7 – 9. The activity can easily be extended to grades 10-12.

Why would I want to use the Herschel Experiment in my classroom?

It provides an interesting and historical hands-on experiment that allows students to discover an important part of the electromagnetic spectrum, infrared light, which is not visible to our eyes.

How could I use this activity with my students?

·  As an outdoor class lab activity.

·  As a student learning station or as a teacher demonstration (requires a south-facing, sunny classroom window).

·  As part of a student’s science fair project.

Where can I find some easy to understand background information about infrared light?

Visit the SIRTF education web page http://sirtf.caltech.edu/SSC_EPO.html

What do I need to know about the set up for this experiment?

Information that explains how to set up your prism boxes is available at:

http://sirtf.caltech.edu/Education/Herschel/backyard.html and http://sirtf.caltech.edu/Education/Herschel/experiment.html

Can I do the Herschel experiment on a partly cloudy day?

For best results, the experiment should be conducted outdoors on a sunny day. Variable cloud conditions, such as patchy cumulus clouds or heavy haze will diminish your results.

Can I do this experiment in my classroom rather than going outside?

Yes, if you have access to a south-facing, sunny window. If possible, open the window for direct sunlight.

Most of the equilateral prisms that I use are made of acrylic. Will these work just as well as glass prisms?

No, plastic prisms do not work very well.

Why would I use the Fahrenheit temperature scale rather than the Celsius temperature scale to record temperatures?

The Fahrenheit scale offers a finer scale for measuring temperatures, providing higher accuracy. As an additional exercise, consider having students convert their measurements to the Celsius scale.

Are there any tips for using these prism boxes with my students?

·  Select a sunny, non-windy day. (High winds may displace the box during temperature measurements.)

·  Position the box at an angle to get a wide spectrum.

·  Take student binders and textbooks outside to help position and stabilize the light box.

·  Assign jobs that students will perform when outside:

Timekeeper – Announces times for temperature measurements

Measurer – Reads temperatures to recorder

Recorder – Records temperature data on chart

Box-keeper – Makes sure thermometers are positioned properly and holds box if necessary, and is responsible for all materials