I use a laser pointer and a globe in my workshops. The area of the laser
beam on the globe changes as the laser pointer is moved along a line of
longitude. This can be done with Earth in the summer and winter
orientations.
Note that first a student must learn why the sun's rays are parallel so that
they understand why the laser beam is a good approximation to the incident
sunlight. Note that textbooks claim that the sun's rays are parallel when
discussing the seasons, and then switch to non-parallel when discussing
eclipses: this might be somewhat confusing to a student.
Larry Woolf
General Atomics
www.sci-ed-ga.org
www.ga.com
-----Original Message-----
From: Forum for Physics Educators [mailto:PHYS-L@list1.ucc.nau.edu] On
Behalf Of John M Clement
Sent: Thursday, February 24, 2005 9:22 AM
Subject: Re: In the Private Universe
A useful thing would be to have a model of the earth where the students
could observe the amount of light intensity/area. I would propose a globe
with either a light sensor imbedded in it attached to a meter, or a
translucent section that provides light in the interior, and a peephole that
students could observe the light intensity. Then students could see the
effect of the angle. Then they could explore how the angle and the
illumination changes with the seasons.