[LINK]: telescope causal map

	May, 2012

Mr. P's Class • Room 213 • Meigs Magnet School • May 1-22
Telescopes: Astronomy Month 2012
•	LINKS
1	[LINK]	Telescopes From the Ground Up!
2	[LINK]	How Telescopes Work [howstuffworks.com]
3	[LINK]	Telescopes Types (Slides)
4	[LINK]	Telescopes [ece.umn.edu]
5	[PPT]	Telescopes PPT
6	[PPT]	Microscopes PPT
7	[LINK]	Anatomy of a Lens [www.physicsclassroom.com]
8	[LINK]	Light Ray Diagrams [http://hyperphysics.phy-astr.gsu.edu]
9	[LINK]	Behaviors of Waves: Refraction, Reflection, Diffraction [www.physicsclassroom.com]
10	[LINK]	Telescope Causal Map
11	[LINK]	[www.physicsclassroom.com]
12	[PIX]	Dr. Erika's Telescope Drawing (05.01.12)
•	NOTES
1		A lens is a piece of glass or other transparent material that takes a specific shape, convex or concave, to either converge (come together) to a point or appear to be diverging (go apart) from a point.
2		A lens is a grounded or molded piece of transparent (see-through) material that refracts light rays to form an image. Think of a lens as something with lots of tiny refracting prisms inside it.
3		Converging lenses [CONVEX] can be identified by their shape; they are relatively thick across their middle and thin at their upper and lower edges.
4		Diverging lenses [CONCAVE] can also be identified by their shape; they are relatively thin across their middle and thick at their upper and lower edges.
5		If a concave mirror were thought of as being a slice of a sphere, then there would be a line passing through the center of the sphere and attaching to the mirror in the exact center of the mirror. This line is known as the principal axis. The line vertically down a mirror is the vertical axis. The point on the mirror's surface where the principal axis meets the mirror is known as the vertex. The distance from the mirror to the focal point is known as the focal length.
6		Pretend a light bulb is placed in front of a concave mirror somewhere line line with the center of curvature. The light bulb will emit light in a variety of directions, some of which will strike the mirror. Each individual ray of light which strikes the mirror will reflect (bounce). After reflecting, the light will converge at a point. At the point where the light from the object converges, a replica, likeness or reproduction of the actual object is created. This replica is known as the image.
7		Reflection involves a change in direction of waves when they bounce off a barrier. Refraction of waves involves a change in the direction of waves as they pass from one medium to another. Refraction, or the bending of the path of the waves, is accompanied by a change in speed and wavelength of the waves.
•	PICTURES/DIAGRAMS
1		Look at the differences in converging (convex) and diverging (concave) lenses.
2		Notice the vertical axis (like Y) and the principal axis (like X) make a perpendicular angle. The focal point is the exact point at which the rays meet or cross. The focal length it the distance from the vertical axis to the focal point. Do you see those in the diagram?
3		After studying Diagram #4 - #7, what might you think about the reflections (bouncing rays) produced in each of these kinds of mirros?
4		Refraction (bending rays) on a converging lens make the rays cross. Notice the blue lines in and the red lines out. Notice them in this diagram and the next diagram.
5		What statements might you make about refraction on a converging lens?
6		Refraction (bending rays) on a diverging lens make the rays spread wide apart. Notice the blue lines in and the red lines out. Notice them in this diagram and the next diagram.
7		What statements might you make about refraction on a diverging lens?
8		Look at a simple model of how a telescope works.
9		Look at Dr. Erika's drawing of how a telescope lens works. (05.01.12)
•	ASSIGNMENTS
1		Study over the weblinks, PPTs, notes, and diagrams above.
2		Draw each: a) convex lens; b) concave lens; c) simple telescope with light rays
3	[LINK]	Answer each question on the google doc.