Thousands of years ago someone tried to answer the question: Does light travel always in a straight line, even if in a transparent medium, or can it follow its curvature? Using a bucket of water with a hole at the bottom, he discovered the latterhow simple!
Sunlight rays crossing the morning dew droplets formed a rainbow of colors. Thus the sun rays, composed of many colors, were demystified-what a simple observation! Sun rays, when reflected with shining bronze shields, were redirected to selected points called estiai or foci. Furthermore, concentrated rays had so much energy that they could warm up things or burn them. Soon thereafter, the glassy optical lens was produced.
It was found that rays passing through a spherical lens did not create the best focal point; today, this imperfection is known as lens sphericity. It was also discovered that shapes based on hyperbolas or parabolas were better suited to optical applications than those based on circles or spheres.
Simple experiments and observations of the past have helped our understanding about the nature of things. Yesterday's science fiction is today's reality. The electronic properties of conductors and semiconductors help to create or detect light. Three crystals, each with different impurities and fused together, created a transistor, which within a few years revolutionized the way we live. The wrist-size communicator is no longer just fantasy in comic books. Pocket-size powerful computers and credit-card-size communication devices are a reality. Low earth orbit satellite (LEOS) communication networks are not "pie in the sky," but they are roaming the silent skies. At the click of a button, one can access virtuallyany part of the globe and hear and see events as they happen. Optical fiber has wrapped around the globe like a ball of yam connecting all continents and transporting data at the speed of light. Direct-to-satellite communication enables anytime-wireless connectivity between any two places in the world, as well as providing global positioning services with accuracy of a few feet or inches! A single optical fiber can transport the information of hundreds of thousands of volumes within a second.