PolarizationIntroduction:PART ONE: POLARIZATIONMethod 1:Two polarized disks were placed in a slotted holder with their polarization axes aligned and a bright red light-emitting diode (LED) was placed on a side and a light sensor was placed on the other side. The light intensity was measured as a function of the angle of the rotating plastic polarizer from 0 to 180 degrees. Science Workshop was used to measure the intensity for each 5 degree rotation (Fig 1). Method 2: The mineral calcite exhibits birefringence (double refraction) and therefore has two different values ​​for its refractive index. A calcite crystal was placed on top of the print and rotated to see the difference between the two rays, the ordinary ray and the extraordinary ray. A polarizer was then used to observe the images formed by the calcite. Method 3: To determine stress points in a plastic object, we used a photoelastic effect where we looked at the object through a polarizer. When the plastic was compressed together, changes in color occurred, showing spots of increased stress. Method 4: In this method, polarization by reflection from a non-metallic surface was used to help distinguish the plane of incidence and Brewster's angle. A cardboard disc with an image and a polarizer were placed in the holder, with a piece of black plastic (n=1,491) in between. The Brewster angle was determined by tan = n and =56. We then looked through the polarizer at this angle and were able to determine the direction of polarization. We also looked at the reflection of a ceiling light directly above the black plastic to determine whether it was polarized in this case. Method 5: To determine polarization by scattering, a jar was filled with water and milk powder, then a flashlight was shined directly on the top of the jar. From the side of the jar, we looked through a polarizer at the scattered light. From this we determined whether the light was horizontally polarized. PART TWO: LIGHT MEASUREMENTS Method 1: A halogen light source was placed at the end of a meter, and a light sensor was placed on the meter starting 0.1 m from the light source. Science Workshop was again used to measure light intensity between 0.1 m and 1.00 m (Fig.