Dry Cleaning, Video Baby Monitor, GeneratorDry cleaning was discovered in 1855 by accident. Frenchman Jean Baptiste Jolly noticed that a clean spot was made in his tablecloth each time his maid knocked over the kerosene lamp. It eventually dawned on him that the oil from the lamp was lifting oil stains out of the cloth. Next, the first baby monitors became popular in the 1980s. These one-way walkie-talkies allowed parents to listen in on their child from another room. Just hearing their child wasn't enough for some parents, so manufacturers figured out a way to develop a video baby monitor. Here's how it works: The lens directs the light entering the camera onto the ccd. The images are recorded by the pixels as tiny electrical charges while the microphone picks up any nearby sounds. This information is converted to a radio signal that's broadcast to the monitor. Once there, the antenna picks up the signal and sends it to the receiver. It is converted back into electrical charges that are fired at the screen. This becomes the image of your child you see sleeping in the next room. Finally, generators got their start in the mind of Michael Faraday. In 1831, the chemist and physicist discovered that mechanical energy--that is things that are moving--could be converted to electricity. He did it by passing a copper wire through a magnetic field. Thus, the electric generator was born.
