Teachers can teach students about LCD light with a few materials and a dark classroom. Students will hold a polarized sheet in front of an open window and rotate it. Hold up a second sheet with the other hand and rotate both sheets in the same direction at the same time. Repeat the experiment, but rotate sheets in opposite directions. Instructors will turn on an LCD projector and instruct students to repeat the three experiment steps. Discuss the results with the class.
Original television sets were lit using cathode ray tubes, but LCD and plasma televisions are present in nearly every home today. Mechanics and engineering instructors need to provide three television sets, each using the different lighting systems, to examine the differences between them. Ask students to predict which unit produces the most heat, brightest lighting and highest amount of energy consumption. Students should test theories by plugging in the units and turning them on to make observations and collect data that will support or refute each hypothesis.
Advanced biology students will observe the effects of the field of optogenetics. Obtain freely moving worms and place five in a control tank with regular lighting. Place another group of five worms under an LCD projector and watch what happens when the worms or subjected to red, blue or green lighting. Encourage students to formulate theories as to why LCD lights affect the neurons and muscles of tiny organisms and propose possible implications this may bear on human neural and muscular systems.
Elementary and intermediate teachers can introduce the complex concept of light polarization with a quick, inexpensive experiment. Ask students what will happen when they wear sunglasses and look at a computer screen. Have students test their theory. They will observe that the light from the screen dims when they wear sunglasses. Instruct students to hold the sunglasses out and slowly rotate them, carefully watching the screen through the lens. At one point during the rotation, the screen view will completely disappear in the lens. Discuss why this happens in accordance with scientific principles regarding the linearly polarized light produced by the LCD screen and the polarizing filters contained in sunglasses.