A: Thomas Paine believed that the American army would become the strongest in the world, that America would achieve independence from Britain with a strong ar... Full Answer > Filed Under:
How DVDs Work. DVDs are of the same diameter and thickness as CDs, and they are made using some of the same materials and manufacturing methods. Like a CD, the data on a DVD is encoded in the form of small pits and bumps in the track of the disc. A DVD is composed of several layers of plastic, totaling about 1.2 millimeters thick. Each layer is created by injection molding polycarbonate plastic.
To accomplish this task, when you actually place a DVD into a Blu-ray Disc player, the Blu-ray Disc player activates the red laser assembly so that it can read the DVD. In addition, when you place a CD into a Blu-ray Disc player, the same red laser assembly that is used to read DVDs is refocused to read the CD.