Light

Light which travels in straight lines is also a wave. In this unit you need to be familiar with some of the really interesting effects of light, such as reflection and refraction and how these effects are useful for us.

Light Key Vocabulary - Key Words & Their Definitions.

• Incident ray - The incoming ray.
• Reflected ray - The outgoing ray.
• Normal line - From which angles are measured, at right angles to the surface.
• Angle of reflection - Between the normal and reflected ray.
• Angle of incidence - Between the normal and incident ray.
• Refraction - Change in the direction of light going from one material into another.
• Absorption - When energy is transferred from light to a material.
• Scattering - When light bounces off an object in all directions.
• Transparent - A material that allows all light to pass through it.
• Translucent - A material that allows some light to pass through it.
• Opaque - A material that allows no light to pass through it.
• Convex lens - A lens that is thicker in the middle which bends light rays towards each other.
• Concave lens- A lens that is thinner in the middle which spreads out light rays.
• Retina - Layer at the back of the eye with light detecting cells and where an image is formed.