The Light Bulb: One of the Most Useful Inventions in the World

People need light to be able to see. In the morning, there is sunlight. But in the night, people use electric light made from light bulbs. Without light bulbs, people would not be able to see and would have to rely on their other senses to do tasks. Without light bulbs, our lives would be very different. The light bulb is a very useful invention that people all over the world use every day. The creation of the light bulb can be traced back to the 19th century. In 1800, Humphrey Davy made the arc lamp (â€Å"Lighting†). But the arc lamp was very dangerous because light was made by sparks, increasing the chance of fire (Burnie 52). In 1860, Joseph Swan made an incandescent light bulb. But the light bulb had many disadvantages. The light bulb burned out in an hour and it cost a lot of money (Burnie 52). Also, the filament was made of pure carbon, so when the carbon burnt, it filed the bulb with soot (â€Å"Lighting†). Then in 1879, Thomas Edison made a better incandescent (a term for heat-driven light emissions) light bulb. Time News reported, â€Å"Thomas Edison is the creator of the first commercially viable light bulb. † His incandescent light bulb was efficient, affordable, and safe (Fletcher). It took Edison years to make an incandescent light bulb. First he used a platinum filament and used a vacuum pump to reduce the oxygen level in the bulb, so it would be harder for a fire to start (Mintz 83). Later, he coated the filament with magnesium. He tested the bulb. Its electrical resistance was only 3 ohms, meaning that it doesn’t glow brightly. But it did glow for 13 hours and 38 minutes, proving it’s possible to keep a filament lit for long periods of time. Then he decided to use carbon because it was cheap and had a high melting point (Mintz 86). He used a fat piece of carbon, but its electrical resistance was only 2 ohms (Mintz 88). Then he made the piece thinner and longer, so the electrical resistance increased to 113 ohms (Mintz 89). Mintz said, â€Å"For example, if the same amount of water was put in a straw and a big water pipe, the pressure of the water in the straw would be a lot more† (90). Electrical resistance works the same way. Because he made the filament smaller, its electrical resistance increased, but it burned out in a few seconds. Finally, he made a filament that gave the best results. He used a piece of carbon, boiled in sugar and alcohol, and then baked in an over. Its electrical resistance was 107 ohms and it lasted 170 hours. Thomas Edison wrote in his diary, â€Å"My light is perfected† (Mintz 90). Thomas Edison created an incandescent light bulb, but now there are many others. One of them is a standard light bulb. It is an incandescent light bulb with 20 inches of filament made by tungsten (a metal discovered in 1912) surrounded by gases. It makes yellow-white light, but its efficiency is only 8%, meaning that only 8% of the electricity input is used to make light. The other 92% is used as heat or is passed to the other end of the filament. A daylight bulb is an incandescent light bulb, but is made to give the color and feel of daylight. It is made of many colors (Burnie 53). A fluorescent bulb works by passing current through a tube, producing ultraviolet radiation. The radiation hits the phosphorous coating, making light through chemical process. The bulb lasts about 10,000 hours. There is also a compact fluorescent bulb. They work like normal fluorescent bulbs, but are smaller and screw into sockets like incandescent light bulbs. Compact fluorescent bulbs also last about 10,000 hours (Kremer). Another type of bulb is low-pressure sodium lamp. It contains a little sodium, so it takes a few minutes to light up. The light it makes is almost pure yellow. A high-pressure sodium lamp contains sodium and aluminum. It makes pink-blue light. It is very efficient (Burnie 53). Another type of light is LED (light emitting diode). Compared to all the other types of light bulbs, LEDs are very unique and different. They have no filament, have a long life span, produce no heat, are very efficient, and one bulb is less than an inch long and about a centimeter wide. Unfortunately, they are very expensive. For under-the-cabinet lighting in a kitchen, one strip of it costs about $100 (Kremer). Overall, there are many different light bulbs now, and more will be invented in the future. There are many different light bulbs for different uses. Each light bulb can be used in at least one way or another. For example, daylight bulbs are used inside of buildings (Burnie 53). So are incandescent bulbs, fluorescent, compact fluorescent, and LED (Kremer). Low-pressure and high-pressure sodium lamps are used outside. More specifically, low-pressure sodium lamps are used in less populated areas, such as driveways. High-pressure sodium lamps are used in more populated ideas, such as streets. Incandescent bulbs, compact fluorescent, and LED bulbs are used in appliances and household objects, such as microwaves, flashlights, and cars (Burnie 53). All these bulbs help us see. Bulbs used inside buildings help us find objects in the night. Street lights make it safer to go bike riding, walk, or drive a car outside when it is dark. Bulbs used in household objects and appliances help us in many ways. For example, the bulb inside a refrigerator enables us to see food. The light in a flashlight helps us see in places where there is no light. All in all, light bulbs have many uses. The invention of the light bulb is very useful and everyone uses it. Without the light bulb, our lives would be very different. We would either have to use candles and risk the chance of fire, or not use candles and not be able to see at all in the night. I think that light bulbs help us every day, day and night, and are less dangerous than fire and candles.