First principles and reflection

Description: Episode of Series “Light”. Demonstrates how light is invisible and how light travels in straight lines. Beams of light are used to show the formation of shadows, both umbra and penumbra. Solar and lunar eclipses are illustrated by diagrams and actual photographs. Explains the laws of reflection at a plan surface, the equality of angles of incidence and reflection being compared with the movement of a billiard ball. Practical examples are used to illustrate the formation of images in plane mirrors and the lateral inversion of these.