Paper Plate Education
Activity: Sub-Solar Cup
Throughout the year, this simple device will indicate where on the Earth the sun is currently overhead. See the Analemma activity to plot a figure-8 analemma (right) on a globe using the Sub-Solar Cup.
Drill a small hole out of the bottom of a dark plastic cup. On the top of the cup secure two pieces of thread to make a set of cross hairs. Cut out a viewing window on the side of the cup.
Secure the globe on its side so that a figure standing at the observers location is upright on the globe. That is, a tangent at the observers location is parallel to the ground. Align the figures line of longitude on the globe with your north-south meridian.
View the location of the sun at local noon throughout the year to track the suns annual migration between the tropics.
This activity, contributed with original reference by Gary Tomlinson, is an adaptation of an activity written by Robert Mitchell. See The Physics Teacher, May 1991, pp. 318-319.
GLPA Proceedings, 1999, pp. 36-36.
[Note: This activity is included in the Paper Plate Astronomy video/DVD/streaming video.]
Copyright ©2012 Chuck Bueter. All rights reserved.