The document discusses the history and evolution of artificial light sources from their inception to modern times. It begins by distinguishing natural light sources like sunlight from artificial ones invented by humans. The first artificial light source was the incandescent light bulb invented by Thomas Edison in 1879, which used a heated filament to produce light but was inefficient. Fluorescent lights were developed later and were more efficient. Compact fluorescent lights and various discharge lamps further increased efficiency. Recently, LED lights have become most efficient due to lower energy consumption and longer lifespan than other alternatives. The document traces the technological progression of artificial lighting over time to become more sustainable.

1. The Discovery of Artificial Light
Presented by
Arpan Mandal
Ankita Chakrawarti
Moumita Sadhukhan
Koustabh Sengupta
Anal Mandal

2. Index
 Introduction to light sources
 History of artificial light types
 Evolution of light
 BULB
 Fluorescent Light
 CFL
 Discharge Lamp
 LED
 Conclusion

3. Light Sources
Light Sources
Natural
Sunlight
Moonlight
and
Lightning
Artificial
Incandescent
Bulbs
Fluorescent
lamps, LED
lamps, etc.

4. What is Artificial lighting?
 Man made lighting
 For human to function properly
 All artificial light can be turned
on and off with a switch

6. Evolution of Artificial Light
1. Incandescent Light (BULB)
 Thomas Alva Edison invented the
first electric light bulbs in
1879AD
 Filament heated by an electric
current produces light rays
 Less energy efficient

7. Evolution of Artificial Light
1. Incandescent Light (BULB)
 Contains Nitrogen or Argon gas
 Tungsten filament with lead wires burns when
electricity is passed
 Also called as tungsten filament bulb
 Advantage-light quality and color are very
consistent
 Disadvantage- requires lot of energy and faster
degradation of filament leading to shorter
lifespan

8. 2. Fluorescent Lights
 Low pressure mercury-vapor gas-
discharge lamp that uses fluorescence
to produce visible light.
 More Energy efficient than
incandescent light
 Peter Cooper Hewitt, Edmund Germer
invented mercury vapor lamp
 Firstly, fluorescent tube lights were
invented and improved in 1934 AD
by George Inman and Richard Thayer
Evolution of Artificial Light

9. Evolution of Artificial Light
 In a CFL, an electric current is driven
through a tube containing Argon and a
small amount of Mercury vapor. This
generates invisible ultraviolet light that
excites a fluorescent coating
(called phosphor) on the inside of the
tube, which then emits visible light.
3. Compact Fluorescent Lights

10. Evolution of Artificial Light
4. Discharge Lamps
 Discharge lamps provide high luminous efficiency combined with long
life, resulting in the most economical light source available
Types of gas-discharge lamps:
A- Low pressure discharge lamps
B- High pressure discharge lamps
C- High-intensity discharge lamp

11. Evolution of Artificial Light
5. LED (light emitting diode)
LED is high intensity discharge light, it uses
semi-conductors to convert electrical energy
directly into light.
 Colorful LED indicators were
invented at the time of CFLinvention
 LED began just as indicator in
calculators, traffic signs, etc.
 White LED lights were invented by
Nick Holonyack in 2006
 Become most efficient light sources as it
consumes less energy and lifespan is
higher than other
Advantage: colorful
lights and highly
efficient

12. Conclusion
 Natural and artificial lights both are important for daily life
 There are different types of artificial light and basic lighting types
 Artificial Lighting properties can vary the use of light in different
areas
 Energy consumptions of artificial lights are reduced by evolution
 In the end artificial lights are useful in any purpose

13. References
• Thomas Edison facts. (n.d.). Retrieved from
http://thomasedisonfacts.com/
• Lebednik, C. (2009, November 11). How has the Light bulb changed over the years?
https://sciencing.com/lightbulb-changed-over-years-5631574.html
• Enchanted Learning. (2010). The Invention of the Light Bulb: Davy, Swan and Edison
https://www.enchantedlearning.com/inventors/edison/lightbulb.shtml
• Blank, C. (2009, August 13). What Elements Are in Light Bulbs?
https://sciencing.com/elements-light-bulbs-7615670.html

14. THANK YOU !