Light & Optics

Color-01

Color

Black Box

Show that aperture looks black even using box with white interior.

2 boxes with small aperture

Inside of arbitrary color

Color-02

Dispersion

Diffraction Glasses +
Spectrum tube carousel

Show the spectral lines that make up the various colors.

Diffraction glasses

Spectrum tube carousel and power supply

Color-03

Dispersion

Diffraction Glasses +
Incandescent Lamp

Put on glasses, look around, and see rainbows.
Look at lamp to see complete rainbows.
Look at flourescent lights to see incomplete rainbows.
White light is made up of lots of colors.

Diffraction glasses

Incandescent lamp

Color-04

Filters

Diffraction Glasses and Filters

Place filter on overhead.

Use paper to mask all but a narrow vertical stripe.
Use diffraction glasses to see the colors transmitted by the filter.
Works great for cyan and yellow, less well for magenta.
Need to show students what they are looking at.

Diffraction glasses

Color filters (cyan, yellow and magenta)

Color-05

Filters

Laser and Filters

Shine red laser through red filter onto screen in dark room. (Some is reflected, some is transmitted)
Shine red laser through blue filter onto screen in dark room. It is absorbed.
Try other combinations.

Red and green lasers

Red, grean, and blue filters (eg: red food coloring in water in glass, same for green and blue)

Color filters (cyan, yellow and magenta)

Color-06

ColorAddition

3 Color Lamps

TEST SPOTLIGHTS BEFORE USING FOR COLOR BALANCE!
TEST OBJECTS TO SEE HOW THEY APPEAR IN THE VARIOUS LIGHTS!
Follow Hewitt's skit for showing color addition (see instructor manual).
Start with white light, then show single colors, and pairs of colors.
Show different color shadows.
Show colors of different objects in the spotlights.
Show colors of C, Y, and M filters in the spotlights (both reflected and transmitted).

RGB spotlights

Various colored objects

Color filters (cyan, yellow and magenta)

Color-07

Persistance of Vision

Color Wheel

Spin it and see white.

Color wheel

Cordless drill

Color-08

Persistance of Vision

Flashing Pendant

Pendant appears white.
Swing it around and you see RGB
Demonstrates:

A) Color persistence

B) Color addition

Flashing pendant

Color-09

Fluorescence

Fluorescent Dyes

Add several drops of flourescent dyes to water.

Show how they glow under a UV lamp.

UV lamp

Flashlight

Various flourescent dyes

Beakers

Water

Persistance of Vision

Benham's Disk

Spin and watch as the black bars appear to have color.

As it slows down the colors will change.

Benham's disk

Reflection-01

Reflectionfrom Flat Surface

Standing Mirror

1 volunteer stands at mirror and adjusts slides until the second vol can see there entire height.
Vol 2 now moves a lot closer (or further).
How much mirror do they need now?

Standing mirror

2 volunteers

Reflection-02

Reflectionfrom Flat Surface

Small Planar Mirrors

Hand them out.
Look at self in mirror.
Close one eye.

How much of head do you see?
You want to see more. Move mirror?

Small planar mirrors

Reflection-03

Reflection from Curved Surface

Curved Mirrors

Hand them out.

Look at self.

Curved mirrors

Reflection-04

Reflection

Mirrors Reverse?

Ask class: What direction do mirrors reverse?
Face mirror.
Hold out left arm. Is it on the audience's right?
Hold out right arm. Is it on the audience's left?
Do same for top/bottom.
Point into mirror. Which way does the image point? Out!

Dark rear projection screen

Reflection-05

Internal Reflection

Optical Fibers

Shine laser through.

Green laser

Optical fiber

Reflection-06

Internal Reflection

Optical Fiber Toy

Light it up.

Optical fiber toy

Reflection-07

Internal Reflection

Lucite Spiral

Shine through.

Lucite spiral

Lucite curved bar

Laser

Reflection-08

Internal Reflection

Laser Waterfall

Support laser on lab stand so it shines on the plug in the waterfall tube.
Fill tube with water.
Darken room.
Turn on laser.
Pull plug.
Makes sure the water lands in the catch basin.

Laser waterfall

Green laser

Water

Bucket

Lab stand

Reflection-09

Internal Reflection

Flashlight Waterfall

Cover the pickle jar with dark paper so the paper extends below the bottom.
Fill with water and screw on the lid.
Hold the flashlight pointing at the (unmasked) bottom.
Tilt and let the water pour out.

Pickle jar with large hole in side and smaller hole in the lid

Flashlight

Bucket

Reflection from Curved Surface

Large Concave and Convex Mirrors

Use the two mirrors to discuss reflections from a curved surface.

2 foot diameter concave and convex mirrors

Reflection from Flat Surface

Right Angled Mirrors

Setups using 2 or 3 mirrors at right angles to each other.

Reflection from Flat Surface

Mirror Tracing

Place the paper on the bottom section of the box.

Use the shelf to block the view of their hand.

Have the volunteer attempt to trace the shape while watching their reflection.

Box with a flat mirror and shelf

Printed out shapes to trace

Pencil

Reflection from Flat Surface

Infinity Mirror

Turn on the lights.

Infinity mirror

Refraction-01

Refraction

Rod in Beaker

See 'break' in rod.

Rod

Beaker of water
(Several to pass around)

Refraction-02

Refraction

Coins in Beaker

Look directly down at coins.
Hold hand by side of glass at the same perceived depth.
Compare to actual depth.

Coin

Beaker of water
(Several to pass around)

Refraction

Laser Refraction Tank

Move the laser around the perimeter to show how the angle of refraction changes.

Can be used with prisms or with water.

Laser refraction tank

Water

Prisms

Human Anatomy

Human Eye

Use the models to discuss how the human eye works to see visible light.

Models of the anatomy of the human eye

Lenses-01

Lenses

Various Lenses

Pass them around.

Various lenses

Lenses-02

Lenses

Wall Image

Place mask on spotlight.
Shine on screen.
Place lens between to focus the image on the screen.
Will covering half the lens block half the image? Which half?

Spotlight

Mask with asymmetric hole

Lens

Screen

Diffraction-01

Diffraction

Slit Diffraction

Shine laser through slide onto far wall.
Darken room.

Laser

Lab stand

Slide with single slits, double slits, and diffraction grating

Polarization-01

Polarized Light

Polarizing Sheets

A) Show one blocks some light.

B) Show a second blocks from 0-100% additional light.
C) Show crossed polarizers pass no light.
D) Show adding a third sheet between crossed polarizers lets light through.
E) Hold filter in front of computer projector.

Show different colors are polarized differently.

3 polarizing sheets

Polarization-02

Polarization

Large Scale Polarization

Tie one end of rope down.
Get volunteer to hold cooling rack.
Shake rope

Only 1 direction of shake gets through.
Crossed racks let nothing through.

Thin rope

Two oven cooling racks

Radiant Flux

Radiometer

Turn on the flashlight and watch the radiometer spin.

Ask why it spins one directions versus the other.

Turn on the bright setting and it will spin faster.

Radiometer

Flashlight with different settings