For years, I knew fiber optic cables works by transmitting light (instead of electricity), which travels at speed of light and probably the future of all cables. Well, for those of you who don’t understand the ins and outs of fiber optics, here’s a great demo by the Engineer guy who shows you how light can travel in liquid, similar to how fiber optics work.
Also see Wikipedia:
An optical fiber is a flexible, transparent fiber made of very pure glass (silica) not much bigger than a human hair that acts as a waveguide, or “light pipe”, to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of optical fibers is known as fiber optics. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication. Fibers are used instead of metal wires because signals travel along them with less loss and are also immune to electromagnetic interference. Fibers are also used for illumination, and are wrapped in bundles so they can be used to carry images, thus allowing viewing in tight spaces. Specially designed fibers are used for a variety of other applications, including sensors and fiber lasers.