If anyone asks me "What is light?" - I am in the dark. Scientists still don’t know precisely what light is. Experiments conducted for over a hundred years has only shown that ilight strikes our eyes in packets of energy known as photons. Until recently it was thought of as either a wave or a particle, but recent experiments have shown that it is both a particle and a wave simultaneously.
Optics is a branch of physics involving the behaviour of light and its properties, including its interactions with matter. Optics usually involves the behaviour of visible, ultraviolet, and infrared light; however, light being a part of the electromagnetic spectrum, other forms of radiation such as radio waves, X-rays and gamma rays also exhibit same properties as light. Optical science and engineering has been the foundation of of scientific and technical advances of the past hundred years.
"Harnessing Light" means exactly what it says - we control and make use of this natural resource in whatever way we can, for the benefit of mankind. Like we have harnessed the wind energy, and we have harnessed solar energy, we have always been harnessing light. From the days of Edison's incandescent lamp with the familiar tungsten filament to the LEDs of today, we light up our homes. Just a few years ago, we thought of LEDs as nothing more than the tiny red lights used as indicators in equipment, but times have changed! With more and more people realizing the energy-efficiency benefits of LED lighting, it seems that everything from headlights to homes and TVs are now being lit up by the versatile light emiting diodes.