My favorite invention is the light bulb invented by Thomas Alva Edison.The modern world is an electrified world.The light bulb,in particular,profoundly changed human existence by illuminating the night and making it hospitable to a wide range of human activity.The electric light,one of the everyday conveniences that most affects our lives,was invented in 1879 by Thomas Alva Edison.He was neither the first nor the only person trying to invent an incandescent light bulb.But what I like most about the invention is the story behind Edison's attempts to improve the useful life of the bulb.He tested
more than 6,000 types of plant materials along with every other filament he could think of,including tungsten,the most common component of modern filaments.Eventually,he tried a carbonized cotton thread,which burned for 15 hours.He continued to improve on that filament until,by late 1880,he had a marketable 16-watt bulb that would burn for 1,500 hours.Now,that's something for an invention.