swirling nebula, - a huge cloud of gas and dust was formed. Eventually this cloud contracted and grew into a central molten mass that became our sun. At first the sun was a molten glow. As the core pressure increased, and the temperature rose to millions of degrees - a star was born. Through the process of thermonuclear hydrogen fusion, the sun began to shine.
THE SUN - (c 4 Billion BC)Our sun is an atomic furnace that turns mass into energy. Every second it converts over 657 million tons of hydrogen into 653 tons of helium. The missing 4 million tons of mass are discharged into space as energy. The earth receives only about one two-billionths of this. Scientists calculate that the sun should keep burning for another 10 to 30 billion years. It has been estimated that in 15 minutes our sun radiates as much energy as mankind consumes in all forms, during an entire year.The sun is approximately 93,000,000 miles from the earth, 864,000 miles in diameter, and is only an 'average' star in size, brilliance and age. There are more than 100 billion other stars in our sun's own galaxy, the Milky Way. Energy, with a color temperature of approximately 6500 degrees Kelvin, is received on earth, from the sun. It takes light from the sun approximately 8 minutes to reach the earth. The illumination on the earth's surface by the sun may exceed 100,000 lux, (10,000 fc) in mid summer.
The first lamp was invented around 70,000 BC. A hollow rock, shell or other natural found object was filled with moss or a similar material that was soaked with animal fat and ignited. Humans began imitating the natural shapes with manmade pottery, alabaster, and metal lamps.
Wicks were later added to control the rate of burning. Around the 7th century BC, the Greeks began making terra cotta lamps to replace handheld torches. The word lamp is derived from the Greek word lampas, meaning torch. Oil Lamps
In the 18th century, the central burner was invented, a major improvement in lamp design. The fuel source was now tightly enclosed in metal, and a adjustable metal tube was used to control the intensityof the fuel burning and intensity of the light. Around the same time, small glass chimneys were added to lamps to both protect the flame and control the flow of air to the flame. Ami Argand, a Swiss chemist is credited with first developing the principal of using an oil lamp with a hollow circular wick surrounded by a glass chimney in 1783.
Lighting Fuels
Early lighting fuels consisted of olive oil, beeswax, fish oil, whale oil, sesame oil, nut oil, and similar substances. These were the most commonly used fuels until the late 18th century. However, the ancient Chinese collected natural gas in skins that was used for illumination.
In 1859, drilling for petroleum oil began and the kerosene (a petroleum derivative) lamp grew popular, first introduced in 1853 in Germany. Coal and natural gas lamps were also becoming wide-spread. Coal gas was first used as a lighting fuel as early as 1784.
Gas Lights
In 1792, the first commercial use of gas lighting began when William Murdoch used coal gas for lighting his house in Redruth, Cornwall. German inventor Freidrich Winzer (Winsor) was the first person to patent coal gas lighting in 1804 and a "thermolampe" using gas distilled from 
wood was patented in 1799. David Melville received the first U.S. gas light patent in 1810.
Early in the 19th century, most cities in the United States and Europe had streets that were gaslight. Gas lighting for streets gave way to low pressure sodium and high pressure mercury lighting in the 1930s and the development of the electric lighting at the turn of the 19th century replaced gas lighting in homes.
Electric Arc Lamps
Sir Humphrey Davy of England invented the first electric carbon arc lamp in 1801.
· How Arc Lamps WorkA carbon arc lamp works by hooking two carbon rods to a source of electricity. With the other ends of the rods spaced at the right distance, electrical current will flow through an "arc" of vaporizing carbon creating an intense white light.
All arc lamps use current running through different kinds of gas plasma. A.E. Becquerel of France theorized about the fluorescent lamp in 1857. Low pressure arc lights use a big tube of low pressure gas plasma and include: fluorescent lights and neon signs.
First Electric Incandescent Lamps
Sir Joseph Swann of England and Thomas Edison both invented the first electric incandescent lamps during the 1870s.
· How Incandescent Lamps WorkIncandescent lightbulbs work in this way: electricity flows through the filament that is inside the bulb; the filament has resistance to the electricity; the resistance makes the filament heat to a high temperature; the heated filament then radiates light. All incandescent lamps work by using a physical filament.
Thomas A. Edison's lamp became the first commercially successful incandescent lamp (circa 1879). Edison received U.S. Patent 223,898 for his incandescent lamp in 1880. Incandescent lamps are still in regularly use in our homes, today. 
This bulb keep us lighted more than one hundred years
Lightbulbs
Contrary to popular belief, Thomas Alva Edison did not "invent" the first lightbulb, but rather he improved upon a 50-year-old idea. For example: two inventors that patented an incandescent lightbulb before Thomas Edison did were Henry Woodward and Matthew Evan. According to the National Research Council of Canada:
"Henry Woodward of Toronto, who along with Matthew Evans patented a light bulb in 1875. Unfortunately, the two entrepreneurs could not raise the financing to commercialize their invention. The enterprising American Thomas Edison, who had been working on the same idea, bought the rights to their patent. Capital was not a problem for Edison: he had the backing of a syndicate of industrial interests with $50,000 to invest - a sizable sum at the time. Using lower current, a small carbonized filament, and an improved vacuum inside the globe, Edison successfully demonstrated the light bulb in 1879 and, as they say, the rest is history."
See - Timeline of Lightbulbs
First Street Lamps
Charles F. Brush of the United States invented the carbon arc street lamp in 1879.
Gas Discharge or Vapor Lamps
American, Peter Cooper Hewitt patented the mercury vapor lamp in 1901. This was an arc lamp that used mercury vapor enclosed in glass bulb. Mercury vapor lamps were the forerunners to fluorescent lamps. High pressure arc lights use a small bulb of high pressure gas and include: mercury vapor lamps, high pressure sodium arc lamps, and metal halide arc lamps. Neon Signs Georges Claude of France invented the neon lamp in 1911.
Tungsten Filaments Replace Carbon Filaments American, Irving Langmuir invented an electric gas-filled tungsten lamp in 1915. This was a incandescent lamp that used tungsten rather than carbon or other metals as a filament inside the lightbulb and became the standard. Earlier lamps with carbon filaments were both inefficient and fragile and were soon replaced by tungsten filament lamps after their invention. See - Tungsten Wire History
Fluorescent Lamps
Friedrich Meyer, Hans Spanner, and Edmund Germer patented a fluorescent lamp in 1927.
One difference between mercury vapor and fluorescent lamps is that fluorescent bulbs are coated on the inside to increase efficiency. At first beryllium was used as a coating however, beryllium was too toxic and was replaced with safer florescent chemicals.
Halogen Lights
U.S. Patent 2,883,571 was granted to Elmer Fridrich and Emmett Wiley for a tungsten halogen lamp - an improved type of incandescent lamp - in 1959. A better halogen light lamp was invented in 1960 by General Electric engineer Fredrick Moby. Moby was granted U.S. Patent 3,243,634 for his tungsten halogen A-lamp that could fit into a standard lightbulb socket. During the early 1970s, General Electric research engineers invented improved ways to manufacture tungsten halogen lamps.
In 1962, General Electric patented an arc lamp called a "Multi Vapor Metal Halide" lamp.
The next generation of illumination world. LED
In next article ,we will introduce the history of LED .
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