Kinesthetic Model of Refraction
Light slows down and bends (refracts) when it travels from one medium into another, such as from air to water or plastic. This kinesthetic activity helps young scientists understand and remember how light bends and why.
Grades: 1 to 5
Duration: 1/2 Hour – 1 Hour
Supplies: Masking Tape, An outdoor sidewalk that runs along a grassy field OR A large, flat area for marching students
NGSS Connections PS4.B: Electromagnetic Radiation
- Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.
- The path that light travels can be traced as straight lines, except at surfaces between different transparent materials (e.g. air and water, air and glass) where the light path bends (MS-PS4-2)
Bring your whole classroom to your chosen spot:
a. either an outdoor area with a sidewalk that lines a grassy field, in which case the sidewalk represents “air” and the grassy field represents another medium (water or plastic)
b. OR, indoors, create a boundary between media with a long strip of masking tape.
First, get students to march in step with a uniform pace and then learn to change to steps half as long with the same frequency on your mark. It helps to count out “left-right, left-right” until they are able to march in both ways.
Line students up in fours, each tier with linked arms to imitate consecutive wavefronts. Then let them march on the sidewalk or on the “air” side of the tape – approaching the boundary at an angle (as in the drawing above).
As soon as each crosses the boundary s/he must change to steps half as long. This will slow down, as students crossing the boundary will cause the direction of the “light” to shift.
Once they have all crossed, have them travel in the other direction – taking half steps until they cross back out into air where they again resume full steps – causing the “light” to bend back to the angle that they began with!