Light
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Princess story:
Once upon a time, there was a Princess who lived in the Kingdom of Light. Everything was beautiful there. It was bright, and full of color, and magic. One terrible day, some evil villains captured her, and took all of the magical light away from the kingdom. She was put in a lonely cell at the back of the dungeon, and locked up with nothing but her mirror. The evil villains wrote the code for her lock on the wall of the dungeon, but she could not see it from her cell. As the princess wasted away, she began to think of ways to get out. Using scraps of bread from her meals, She trained a dungeon rat to come to her. The princess gave the rat her mirror, and she lured it out to the middle of the room. The mirror was able to reflect the code back to the princesses view. She read the numbers, and unlocked herself from the cell. Her triumph returned all of the light and magic to the Kingdom, and banished evil forces forever!
Where do you think the rat should put the mirror in order for the princess to see the secret code?
Cell
Code
Explore:
Turn the lights off, lay a mirror flat on a table, and point a laser pointer at it. Experiment with changing the angle of the mirror and the laser.
What are some things you notice about light and reflections?
Explain
These are two basic properties of light that are helpful to understand.
Light travels in a straight line
You cannot see something when something else is blocking it. Light cannot travel through or around the obstruction.
Mirrors reflect light out at an angle equal to the angle it went in
If light goes in the mirror at 90 angle, it will reflect out at a 90 angle.
Expand: Creating Periscopes!
Step 1- Plan
First create a plan for how the periscope will work. The goal is to be able to see over a wall. The two mirrors must work together to reflect the subject to the viewer.
How should they be angled?
What kind of structure will hold them in place?
Keep in mind what we observed about light and reflection!
Step 2- Build
1) Create the structure of the periscope. This can be done with anything, including recycled materials like cardboard, wire,or plastic.
2) Decide, measure, and mark where the mirrors will go
3) Attach Mirrors with glue/ tape
4) Test the periscope and adjust mirrors as necessary to be sure it is functional!