1. OPTICS
PHYSICS UNIT

2. SOURCES of LIGHT

3. The production of light
Objects that PRODUCE light are LUMINOUS
EX. light bulbs
NON-LUMINOUS objects DO NOT produce their own light
EX. moon

4. Types of light Incandescence:
heating a substance to a very high temperature
Ex. Light bulb has metal wire (tungsten) that gets heated to 2200oC
HowStuffWorks "How Light Bulbs Work“
Nelson Science

5. 2. Fluorescence high UV radiation gets absorbed
ex. highlighter markers
Fluorescent and Compact Fluorescent Lights (CFLs):
mixture of mercury and argon gases
releases less heat

6. Optical Illusions Who Do You See?
20 Incredible Optical Illusions | DailyCognition.com

7. 3. LED (light-emitting diode)
pass electrical current through them
don’t heat up so stay cool
most energy efficient
ex. ‘new’ Christmas lights, digital clocks…
HowStuffWorks "How Light Emitting Diodes Work"

8. 4. Phosphorescence like fluorescence, energy gets absorbed
however, gets released slowly over time
ex. glow in the dark materials
YouTube - IAI Presentations Famous People Players
Steve Spangler Science - Tools and tips that make learning science fun!

9. 5. Chemiluminescence 6. Bioluminescence
chemical reaction that produces light
ex. glow stick
6. Bioluminescence
chemiluminescence in livng organisms
ex. fireflies, jellyfish…
HowStuffWorks Videos "Cool Underwater Creatures"

10. 7. Triboluminescence
light produced when certain crystals rubbed together or crused
ex. eating Wintogreen Lifesavers in the dark!

11. 8. Electrical Discharge
Produced by electrical current passing through a gas causing gas to glow
ex. neon lights, lightning

12. Optical Illusions Who Do You See?
20 Incredible Optical Illusions | DailyCognition.com