Blue Skies and Parallax Day

If you missed today, this is what we accomplished:  In 2013-2014 we had the power out all of period 1 and most of period 2 and all science teachers were pulled periods 7th and 8th with substitutes so periods 7 & 8 were shown how to do the lab yesterday so everyone actually completed the lab (Images, Images, Images) today.  Most turned in the lab today but it is due tomorrow for 8 points in Mr. Konichek's classes.  I am looking for all labeling done in the first sketch (image, object, image distance S sub o and object distance S sub i measured and labeled, and the angle of incidence and angle of reflection measured and labeled, AND arrows showing the path the ray of light took from the object to the mirror and then the reflection to your eye also labeled.

1.  We broke up into our lab groups from yesterday and finished yesterdays lab (images images images) but with understanding the Physics behind each part:

Part 1 Discovering the path a ray of light would have to take to see one point of the image.  Note the following part 1 diagram done on the Smart Board period 1:  Part 1 Diagram  note the brain takes the light it sees straight to the image so that line has to be drawn from the eye to the image in back of the mirror first.  Then a ray of light has to be coming from the object to the spot on the mirror where the line you just drew (from the eye to the image) intersected the mirror.  This ray from the object reflected off the mirror to your eye.  Now drawing a perpendicular (a normal) you measure the two angles noticing the angle of incidence (between the normal and the ray from the object to the mirror) equals the angle of reflection (between the normal and the ray to your eye).  You also connect a point on the object to the corresponding point on the image (I connected the centers of the object and image) and notice the shortest (perpendicular) distance to the mirror from the object point and the image point are equal.  Thus the two laws of reflectiion:  distance of object = distance of image and angle of incidence = angle of reflection.

Part 2 Note the diagram for part 2: from period 1 smart board notes.  When two mirrors are at right angles you see three images in the two mirrors.  One image comes from each of the two mirrors like in part 1 (distance of object = distance of image for each mirror) but where does that 3rd image come from.  Note I placed an eye, traced a ray from the eye to the 3rd image, reflected the spot the ray hit the mirror (so the angle r = angle i)and hit the 2nd mirror, then traced a ray from the object to this spot on the 2nd mirror.  Note the path now for the 3rd image goes from the object to one mirror, reflects from this 1st mirror to the 2nd mirror, and reflects a 2nd time to your eye, and your brain takes this ray straight back to make the 3rd image.  Note also that angle i = angle r for both reflections.

You do NOT have to draw this diagram but do need to draw the 2nd mirrors position as you decrease the angle made with the 1st mirror in getting from 3 images, to 4 images, to 5 images, etc. to at least 8 images.  I do need you to fill in the table for part 2 that indicates the number of images and the angle between the mirrors.  Also need the diagram with the right angle and the three images marked.

Part 3 smart board notes period 1:  Note the previous diagram.   When you draw your face in the mirror you'll notice that the distance between your eyes on the drawing you traced on the mirror is half the true distance between your eyes.  The diagram shows a person (object) looking at the image of their feet in a mirror.  Note the two triangles formed that are similar and the Geometry behind why the ratio is 2:1 for each of the three sides of the similar triangles..

2.  Watch this video to answer the question on the homework sheet of

                Why the Sky is Blue and the Sunset Red??

3.  We found our dominate eye two ways:  1).  Made a triangle with our hands in front of our eyes by our nose, with both eyes open and with an object in the distance in the center of the triangle.  As you shut one eye and then the other, the eye that moves the object the least is your dominant eye.   2).  We held empty paper towel tubes up against each eye looking at objects on two different walls.  If you look harder at the object down one tube and cannot make out the object in the other tube but can kind of see it, then that's your dominant eye as if you stare down your non-dominate eye tube, you cannot make out anything in the other tube.