There are four major ideas in the study of light that are of particular interest to primary scientists:
1. Light comes from a source and travels in straight lines.
2. When it encounters a new material or object, light may be transmitted, scattered absorbed, reflected or refracted,
3. Light can vary in brightness and frequency (colour).
4. Light can be detected by our eyes,
Teaching Concepts
Click on each concept to see Subject facts, Why you need to know these, Vocabulary, Amazing facts, Common misconceptions, Questions and Teaching Ideas
It is important to be aware of how these concepts can be developed in teaching. The following is one way in which the progression can be described. It goes up to Key Stage 3, because it is necessary to know where the children will be going next.To demonstrate your own understanding of the concepts, it is useful to produce your own concept chain.
Things that produce fight are called light sources. The Sun is one of many light sources, We see things with our eyes, We see things either because they produce light or because light bounces off them, You can see things through transparent materials,
Light passes through translucent materials, but you cannot see •through them. Darkness is the absence of light. Opaque materials block light.
Light travels in a straight line from a source. Light sources can be seen when light from them enters the eye. Where light is blocked, shadows are formed. Shadows are the shape of the abject causing them, Light bounces off (is scattered from) objects, allowing them to be seen. Light travels in straight lines from a source to an object to the eye. More light is scattered from bright objects than from dark ones. Very bright, shiny surfaces allow images to be reflected, White tight can be separated into a spectrum using a prism. Red, blue and green are the primary colours of light, and can be combined to produce white light.
Where light is not scattered by an opaque object it is absorbed, Human sight is based on the ability to see red, blue and green light. The colour of an object depends an the colours of light that it absorbs and scatters. Light travels at (metres per second); nothing can travel faster. The path that fight takes can be bent (refracted) when it passes from one transparent material to another. Transparent materials can be shaped into lenses and prisms to alter the path of light by refraction. Curving the face of a mirror will alter the reflection, Concave mirrors and convex can magnify images. Convex mirrors and concave lenses can reduce images.