A flash light is placed at the end of the row of the index cards and lit, after switching off the lights in the experimental room. The light can be seen passing through all the holes.
It can be concluded that light travels in a straight line. In the same way, the holes are in alignment and that since light travels in a straight line; it was observed passing through all the holes. The property of light travelling in a straight line is known as rectilinear propagation. Considering that the sizes of the holes are to be reduces, the light will continue travelling in a straight line but in a more restricted. When the cards were shifted a shadow is formed since the path of light is a straight line and does not bend around the object (Avison 2). Another direct effect of light’s path being a straight line is the casting of shadows by opaque objects.
The concept of the path of light being a straight line is applicable in various areas including the manufacture of mirrors both for domestic and industrial use, movie theaters that use projectors where light is restricted, cameras, human vision, and the casting of a shadow by light on opaque objects explains the formation of day and nights, as well as