Physics 122 Week 8
Light Properties
Linear Light
Use the special FX "canned fog" to show that a laser beam is straight. (Also... who wouldn't want to play with fog and lasers???)
Pinhole Projector
A clear 500-watt light bulb is enclosed in a box with an iris diaphragm. Adjust the size of the iris to show image of the light bulb filament on the wall or ceiling. You may want to project this to your students using a document camera.
Refraction
Simple Refraction
Darken your classroom and get the canned fog handy. Fog up the area, and shine the laser into the acrylic block. Then, slowly begin changing the incident angle!
Water Refraction
A wooden dowel is placed half-way into a tank of water and observed.
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Disappearing Glass (Same "n")
When an object is placed in a medium with the same index of refraction it seems to disappear! Use this demonstration to help walk your students through the ray diagram of why this happens.
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Interference
Two Source Interference
Two transparencies, representing circular wave fronts, are superimposed on overhead projector or document camera. By slowly sliding them over each other you will demonstrate an 2-D interference pattern.
N-Slit Interference
A Cornell slide consists of multiple slit configurations. Rotate the slide to the desired location, and the shine the accompanying laser through it to show how changing the number of slits effects light interference.
Newton's Rings
When looking at the Newton's Rings apparatus you can visually identify interference patterns. You can put this under a document camera or use a mercury light source and reflect it off the Newton's ring apparatus to show the interference to students. **Do Not Adjust The Screws** (No video available)
Diffraction
Single Slit Diffraction Slides
An adjustable Cornell Slide and laser are set on a track. Chose the slit width that you want, and turn the laser on. This works best when the laser is as close as possible to the aperture.
Adjustable Single Slit Diffraction
In order to show your students how slit width affects diffraction send a laser beam is sent through an adjustable single slit. You adjust the slit width by rotating the knob on top of the aperture.
Color Spectrum with Diffraction Gratings
Either pass out diffraction gratings to your students and allow them to look at different light sources, or set up different light sources behind our large diffraction grating.
Spectrum Tubes
When students view these energized gas emission tubes through a diffraction grating they will be able to see the Balmer series for each element. **Do Not Touch The Exposed Leads, and be aware that the emission tubes heat up rapidly if left energized for too long.**
Diffraction Gratings
Here is an assortment of the diffraction gratings we have in the demo room.
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Compact Disk Diffraction
When you shine a laser on a CD it diffracts! Show your students that a CD does in fact have microscopic texture.