Description
Set up a He-Ne laser pointer or laboratory laser to shine into a (very weak) solution of milky water or a cloud of chalk dust.
- Before creating chalk dust cloud (generated by slapping two "dirty" erasers together), be aware that some students may be asthmatic. Make sure cloud is not too large to affect even the front row.
- The chalk cloud is very effective (pedagogically), if you extend its scope all the way across the front of the classroom.
NOTE: Make sure that beam is not directed toward any space in the room that students might walk into, e.g. do not direct beam onto a door, above students heads, etc.

Pedagogy:
- Before generating the chalk cloud, ask student if there is light between the laser itself and the red spot that they see on the opposite wall.
- Ask students why they are able to see the laser beam with the chalk dust.

Equipment
Laser, two dirty erasers or a weak solution of milky water in a large rectangular flask

Description
Blackboard optics with single or multiple rays and a plane mirror.
- The PASCO "Blackboard Optics" Chalkboard Set-Up (with magnetic mounts): Draw in normal lines, etc. directly onto the chalkboard. Make sure all is set up precisely before class, equipment’s magnetic mounts are not easy to manipulate during lecture.
- The PASCO "Blackboard Optics" Lecture Counter Set-Up (directly below overhead document camera): Lay equipment on top of butcher paper (available in front office mail room) and use a marker to draw in normal lines, etc. This method is a bit more flexible classroom set-up, as it allows for equipment to be easily changed out for other demos (e.g., Reflection from a Curved Mirror) and can be more easily viewed by class.

NOTE: Do not leave equipment light sources on for very long, mounts can become very hot. Handle with care!

Equipment
Blackboard Optics set, multiple-ray projector, transformer
Support Equipment
Optional: Butcher paper and marker

Description

Equipment

Support Equipment

Description
A full view mirror is shaded/ covered from the bottom until a minimum height for a full view mirror is determined.
Before class: Make sure that the mirror (and its stand) is "perfectly" vertical.
In class:
- Have a volunteer student come up to the front, ask her/ his height, and have class predict the siae of mirror that she/ he will need in order to see her/ his full image.
- Move mirror up or down until student can see the top of his/ her head. (Recheck mirror’s vertical positioning)
- Cover up as much as possible of the mirror’s bottom portion, without covering up their view of their feet. Compare the height of the remaining portion of the mirror with class’s predictions.
- Optional: Ask students if the volunteer will still be able to see her/ his feet if they moved toward (or away from) the mirror. NOTE: Have volunteer be careful with their close-up observations – She/ He will have to look down into the mirror in order to see their feet.

Pedagogy: Have student hold up a brightly colored string to their eyes and direct your placement of the other end of the string at their image’s head’s position and then their image’s feet position

Equipment

Support Equipment

Description
Blackboard optics with multiple rays and a curved mirror.
- The PASCO "Blackboard Optics" Chalkboard Set-Up (with magnetic mounts): Draw in normal lines, etc. directly onto the chalkboard. Make sure all is set up precisely before class, equipment’s magnetic mounts are not easy to manipulate during lecture.
- The PASCO "Blackboard Optics" Lecture Counter Set-Up (directly below overhead document camera): Lay equipment on top of butcher paper (available in front office mail room) and use a marker to draw in normal lines, etc. This method is a bit more flexible classroom set-up, as it allows for equipment to be easily changed out for other demos (e.g., Reflection from a Flat Mirror) and can be more easily viewed by class.

NOTE: Do not leave equipment light sources on for very long, mounts can become very hot. Handle with care!

Equipment
Blackboard Optics set, multiple ray projector, transformer
Support Equipment
Optional: Butcher paper and marker

Description

Equipment
Large concave, convex mirror

Support Equipment

Description

Equipment
Auto Collimating Mirror

Support Equipment
Light Source

Description

Equipment
Support Equipment

Description
Blackboard optics with a single beam and a large rectangle prism of plexiglass.

Equipment
Blackboard optics set, multiple ray projector, transformer

Support Equipment

Description

Equipment

Support Equipment

Description
A helium-neon laser beam is directed through a light pipe to demonstrate total internal reflection. Dim class lights as much as possible.

Equipment
Light Pipe
Support Equipment
He-Ne Laser

Description
Pinholes are pricked in a black paper covering a long filament bulb. Bring the multiple images into one image with a converging lens.

Equipment
Support Equipment

Description

Equipment
Support Equipment

Description

Equipment
Fresnel Lens
Support Equipment

Description
Shine a laser beam through single slits of various sizes.

Equipment
Slides with slits of varying width
Support Equipment
Laser and overhead screen

Description
Have each student look through two fingers at the light from a vertical filament lamp or a discharge tube. Students two fingers form a slit when held close together. The classroom’s overhead fluorescent lights works well for this demonstration.

Equipment
Students and fluorescent lighting

Description

Equipment
Support Equipment

Description
Shine a laser beam through double slits of different widths and spacings.

Equipment
Support Equipment
Laser

Description
Using an overhead projector, pass a beam of light through a very weak of cream or milk and water.
1. Place tall beaker (containing water only at this point) on the overhead projector. A solid matting (with a hole cut out for the base of the beaker) can be placed underneath the beaker to block out the extra light.
2. With the room lights dimmed and overhead projector turned on, have students note the white color of the circle (representing the sun) on the screen.
3. Add a tiny bit of already diluted cream or milk to the water and stir. (You will want to add the smallest amounts of "large" particles as possible, a bit at a time.)
4. Note any changes in the color of the "sun" beam on the screen and any changes in the color of the light scattered from the sides of the solution. Continue adding the cream solution, bit by bit, noting color changes until you have obtained a yellow/ orange sun beam on the screen and a blue "sky" about the beaker.

Equipment
Sunset Package: Diluted cream or milk, tall beaker/ cylinder, long spoon, overhead projector cover w/ cut-out hole
Support Equipment

Description
Pass a beam of light through a solution of sodium thiosulfate and gradually add a diluted HCl solution.
1. Place tall beaker (containing sodium thiosulfate solution only at this point) on the overhead projector. A solid matting (with a hole cut out for the base of the beaker) can be placed underneath the beaker to block out the extra projector light.
2. With the room lights dimmed and overhead projector turned on, have students note the white color of the circle (representing the sun) on the screen.
3. Add a tiny bit of diluted HCl solution to the sodium thiosulfate solution and stir. A chemical reaction will take place in which larger particles are formed.
4. Note any changes in the color of the "sun" beam on the screen and any changes in the color of the light scattered from the sides of the solution. Within a few seconds more and more of these are formed and the white "sun" beam will gradually change from white to light yellow to yellow and then to an orangish yellow. Continue observations until you have obtained a yellow/ orange sun beam on the screen and a blue "sky" about the beaker.

Equipment
Sunset Package: diluted HCl, Sodium Thiosulfate, tall cylinder, long spoon, black overhead projector

cover w/ hole
Support Equipment
Overhead projector

Description
On the overhead, rotate one of two Polaroid sheets.

Equipment
Polarizing sheets

Support Equipment
Overhead projector

Description

Equipment
Eye model
Support Equipment