Inquiry starter descriptions.

1. Pinholes
Set-up:
- three pinhole boxes of varying sizes
  + each pinhole box is created from a cardboard box that starts with
  six good sides (i.e. it has a lid or closable flaps).  We used
  large (~3 feet per side) boxes, but any size will work. 
  1. In the bottom of the box, carve a hole that is large enough to
  fit a human head through. Put the hole near the back side of the box, and
  centered along it's width.  
  2. In the back side of the box, above the head-hole, carve a small
  square or circle (about 2 inches across). This small hole should be
  high enough up on the back side of the box that it is not obstructed
  by the head that will be sticking through the head hole. 
  3. Cover the small hole with aluminum foil or cinefoil, taped down
  to the outside of the box. Poke a pinhole in the foil with a pin or
  toothpick. 
  4. Before sealing up the box, tape down white paper on the inner
  face of the front side, opposite the pinhole you just made.  
  5. Seal up the box with tape. Tape over any cracks or holes.
  6. Attach some black cloth around the head hole. This will drape
  over the shoulders that are attached to the head, keeping light from
  entering through the head hole.

     (top view)                       (side view)         
   +-----------------+  	    +-----------------+  
   |        white -> |		    |        white -> |	
   | __     paper    |		    |        paper    |	
   |/  \             |		    |                 |	
B  |    |<- head     | F	    @ <-pinhole       | 
a  |\__/    hole     | r	    |  ___            | 
c  |                 | o      back  | /  _\  <-head   | front
k  |                 | n	    || (   >          | 
   +-----------------+ t	    +-\___/-----------+ 
                                    _/     \_ <- shoulder drape


   NOTE : if you are using a smaller box, you can carve a hole just
   big enough for the user's eyes, instead of the whole head. In this
   case, the hole should be cut into the back side of the box, so the
   user can look through directly at the white paper on the inside of
   the front.

Procedure:
- Briefly explain how the pinhole box was made. You may want to
  emphasize that it is simply a pinhole poked with a toothpick and
  white paper inside of a dark box. i.e. no tricky lenses or mirrors.
- ask the students to put their heads inside the boxes and look at the
  white paper
- have a second student stand behind the one with his/her head in the
  box and jump around while waving arms
- ask the students to try different boxes (of different sizes)

  NOTE: the inverted images are easiest to see when you stand outside
  in the daylight. To emphasize the left-right inversion, you can use
  a large sign with clear writing on it, or ask a student outside of
  the box to "wave your left arm...wave your right arm"
  You can use boxes with different pinhole sizes to show the
  differences in image clarity and brightness, but many students will
  come up with this idea on their own, so it can be left for the
  investigation stage.
  When students are devising questions from this starter, you can
  suggest that they consider similarities or differences between the
  different boxes.

2. Lenses
Set-up: 
Light source, convex lenses, screen.

Procedure:
- Show the students optics and ask them to inspect them (look through,
feel, investigate shape).

- Show that the light source, 1 convex lens, and the screen placed at
the proper distances will create an image of the light source on the
screen.  Show that moving the screen will make an out of focus image.

- Show that blocking part of the light source will obscure part of the
image (inversely - i.e., image inversion).

- Show that blocking part of the lens will simply dim the image, but
the image is still clear and the entire source is still imaged.

  - You can also image the overhead lights onto the table, if you want.

- Tell the students they can use multiple optics to create different
images.

- Let them play with the materials and formulate questions.

3. Mirrors
Set-up: 
-Red light bulb in power strip, black paper screen, and various concave spherical mirrors
-Two identical mirrors are pre-aligned, set up in clay, and covered with a folded index card

Procedure:
-Demonstrate making an image of the red filament on the paper screen (move in and out of focus)

-Show students a smaller diameter mirror (with a longer focal length)
-Ask students where they think this mirror needs to be placed (relative to the previous, larger diameter mirror) to make an in-focus image on the screen
-Show students that the mirror needs to be further away from the screen
-Make an image with both mirrors at once and allow students to compare images

-Uncover two mirrors set in clay to reveal apparently single image
-Cover/uncover one mirror at a time from various directions and have students observe what happens to image

-Let students experiment with the variety of spherical mirrors and formulate questions