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.
These discs are distinguished from standard DVDs as DVD+R DL or DVD-R DL. Dual-layer DVDs are engineered with two separate layers of recording space on one side of the disc. The first layer is semitransparent so that the laser can shine through to access the second layer.