I Light is a form of energy that enables us to see the world around us. From the time we are born, we learn to see and identify the physical world around us because light energy reflected from the object reaches the retina of our eye. In the absence of any light, we will be unable to see anything like in a dark room. Sun emits light energy. This light energy is a product of nuclear fusion of elements that is happening inside the sun.
Light is emitted in the form of small packets called photons.
Newton propounded the corpuscular theory of light. This is known as duality of light. Light photons or waves always travel in a straight line, unless they are acted upon by a medium. For example, light photons may bend due to extremely heavy mass such as a galaxy. Reflection from a plane surface 2.