The Nature of Light.

Scientist have always been puzzled by the nature of light. In the seventeenth century there were two schools of thought concerning it. Sir Isaac Newton regarded light as a stream of corpuscles or tiny particles travelling in a straight line. The Ductch physicist, Huygens, held that light consisted of waves in a substance called the ether, which he supposed filled the whole of space, including that between the atoms of matter, and which could not be removed even from a vacuum. As time went on and more became known about the behavior of light, Huygen’s wave came to be accepted as the better one. At the present day, however we have reason to believe that light consists of stream of tiny wave-like packets of energy called “photons”, which travel at a speed of 3 x 10⁸ m/s  or 3 x 10⁵ Km/s.

Atoms emit light at the high temperatures produced by chemical reaction in a flame, by the heating of thin tungsten wire in the ordinary electric lap or by the bombardment of gas molecules by electrons in a discharge lamp tube.

The sun and sources as described above are said to be self-luminous, since they emit light of their own accord. The common objects around us are not self-luminous, but we are able to see them because they reflect light from the sun or other sources in all directions. Mirrors and highly polished surfaces reflect light strongly, and we shall now deal with the laws governing the reflection.

Original Article on Scienceplaza