HR: 1340h
AN: ED13C-1158    [Abstracts]
TI: The"Overhead Projector Polarizing Microscope
AU: * Kavner, A
EM: akavner@igpp.ucla.edu
AF: UCLA, 595 Charles Young Drive East, Los Angeles, CA 90095 United States
AB: The light microscope is a valuable tool for mineral identification and characterization. The overhead projector polarizing microscope was developed to help first-year mineralogy students understand the physics of light, and its propagation through transparent materials. This is a simple demonstration that can be adapted for a large lecture or for interactive learning. First, a pair of polarizing filters are placed on the overhead projector, and the top filter is rotated with respect to the bottom to demonstrate the polarized property of light. Next, single crystal calcite is placed between two polarizers that have been oriented to exclude the light. The calcite is rotated with respect to the crossed-polarizers to demonstrate 90° extinction. The demonstration can be extended to include other single crystal minerals, optically active materials such as a quarter wave plate, a color filter to mimic single wavelength behavior, and a quartz wedge to demonstrate the interference color chart. The required materials are: an overhead projector, two pieces of polarizing filters, and a piece of optical quality single crystal calcite. Optional materials include: different color filters, a quartz wedge, and other optical materials. This demonstration of the properties of light and its interactions with materials can be adapted for a range of levels of Earth science and physics instruction including primary and secondary school curriculum. The overhead projector polarizing microscope will be demonstrated at the AGU meeting.
DE: 0820 Curriculum and laboratory design
DE: 0825 Teaching methods
DE: 0845 Instructional tools
DE: 3694 Instruments and techniques
DE: 3994 Instruments and techniques
SC: Education and Human Resources [ED]
MN: Fall Meeting 2005