Spots, Lines and Lasers

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Learners shine the light of a laser pointer through sheets of fabric that all have a different number of threads per inch. By looking at the patterns created, learners calculate the wavelength of the laser. The kit for this activity is no longer available, but you can still complete it if you have four fabrics and you know how many threads per centimeter are in each fabric. This activity starts on p.6 of the manual. This manual contains four activities related to the Spectra: The Original Laser Superhero Force comic book published by the American Physical Society.

Quick Guide

Preparation Time:
Under 5 minutes

Learning Time:
10 to 30 minutes

Estimated Materials Cost:
$5 - $10 per group of students

Age Range:
Ages 11 - 14

Resource Types:
Activity, Experiment/Lab Activity, Lesson/Lesson Plan


Materials List (per group of students)

  • Laser pointer
  • Tape
  • 4 small strips of cloth, each with a different, known thread count
  • 2 binder clips
  • 4 large sheets of paper
  • Meter stick
  • Student's Guide (p.8-9 of PDF)
  • Diffraction Grating Cloth card


  • Mathematics
    • Measurement
      • Units of Measurement
  • Physical Sciences
    • Vibration and Waves
    • Light and Optics
      • Lasers

Informal Categories

  • Literature


To use this activity, learners need to:

  • see
  • read
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


Components that are part of this resource:

This resource is part of:

Access Rights:

  • Free access


  • Thompson-Flagg, Rebecca ; Johnson, Kerry G.


  • All rights reserved, American Physical Society, 2010