Light and Applications of Optics

Unit at a Glance (p272) (don't copy) What is light and how is it produced? How does light interact with objects to give them colour? How can you mix colours to make different colours? What is the law of reflection and how do mirrors form images? What is refraction and how can it be used? What are lenses and what are some of their applications? try the "Get Ready" questions on p.274

Producing Light (p.278) Luminous Non-luminous ( ) ( )

Producing Light (p.278) Luminous Non-luminous (produce light) (reflect light) e.g. e.g.

Producing Light (p.278) Luminous Non-luminous (produce light) (reflect light) e.g. e.g. sun moon lightbulb you

Ways of Producing Light Incandescence (burning, bulbs) Fluorescence (CFLs) Phosphorescence Chemiluminescence Bioluminescence Triboluminescence Light Emitting Diodes (LEDs) Electric Discharge

Incandescence - so hot it glows! 3min how it's made 5 min 1min

Fluorescence (CFLs) - release light when hit by UV rays 1.5 min 8min

Phosphorescence "glow in the dark" - glows after hit by radiation (light) 22 sec

Chemiluminescence - light released during a chemical reaction 3min elephant toothpaste 1min

Bioluminescence - living chemiluminescence 13 sec 2min 3min

Tribouminescence Light from rubbing, scratching or similar friction

Electric Discharge - a gas emits light when electrons pass through 4min 8min

LED Light Emitting Diode/Device an LED produces light when electrons move around within its semiconductor structure Electroluminescence