Spectrum of visible light revisited and redesigned

Each term I have the students in SC 130 Physical Science view the visible spectrum using a CD spectroscope. This follows the viewing the Limits of Light. I have used the CD spectroscope exercise both to frame the visible light spectrum lecture and to tackle the "issue" of indigo. This term I added a slight twist to the lecture demonstration session.

Staisy

I brought crayons and drawing paper and asked the students to draw the spectrum. This had an unexpected consequence: for the first time students were going back and looking at the spectrum again. As this happened I suddenly realized that the students had been only glancing at the rainbow without really analyzing what colors they were seeing and in what order. The introduction of sketching the spectrum shifted this up to the thinking taxonomy to analysis. 

Mauriney, Ellena, Joyann

This also led directly to the issue of indigo, with some students working to ensure that they had seven colors including indigo. Others opted for five or six colors.

Rodman


I asked the student on the left if that sequence is what he say and at first he said yes, then as other students looked and disagreed he chose to say that this was the order he preferred. Introducing sketching forced a deeper and more careful consideration of the spectrum and proved a valuable addition. The session wrapped up with a brief video on Newton's indigo.

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