the fiber optic industry is based on the fact that information can be transmitted on a beam of light. although the speed of light through free space 3*10^8 meters per second, or approximately 186000 miles per second,its speed will be reduced by encounters with other media,causing reflection and refraction. when light information is passed through a fiber optic cable,it is expected to bounce off the walls of the cable.However of the angle at which the light is injected into the cable is critical,as is the actual design of the cable. in Fig 7.69, the basic elements of a fiber optic cable are. the glass or plastic core of