WHAT IS LIGHT? Part 1

 

Simple observation reveal some of more obvious characteristics of life the outline Shadows of in strong sunlight show that light travels in straight at least on a microscopic scale and sunshine  filtering in to a room through small opening appears to form well defined being this gives rise to ideas of rays of light a concept that is useful in appreciating some of the basic properties of light as well as operation of many optical instrument but what is light?

Now by the early 18th century scientist had found that they could explain  many optical effects in terms of general properties of waves as with sound waves and ripples of the surface of water light can be seen to undergo Section refraction,interference,  reflection and diffraction However,  what exactly constituents as a Light wave was not answer until a century letter with the work of the British physician James clerk Maxwell dream together many observation Consulting electricity and Magnetism and incorporated them in a single theory which predicted the existence of electromagnetic waves according to theory this waves travel through a vacuum at the velocity given by two constant related to electric and magnetic units and this velocity is the same as the velocity of light.

One many purpose the wave theory of light is edequate but well it comes to explaining the observation of emissions of light on the atomic scale they the wave description is not tenable light must then be described as packets of energy or particles of light called photons which interact individually with electrons in atoms this discovery of dual nature of light this Monster rating that it was wave and particles brought about the development of quantum theory and revolutionalized physics in 26th century.

 Now the speed of light  

Measuring the velocity of light in a vacuum 299,792.5 km per second is one of the fundamental constants of Physics usually denoted by the letter C as Einstein showed in this special theory of  relativity this Universal speed limit nothing can travel faster than the speed of light in  free space.