Essential Questions 4.5
Once the human race discovered heat engines it was only a matter of time until we put them to work for us. Early machines were very simple but soon grew complicated. Steam engines were a challenge to build and required the development of machine techniques to produce the accurate cams required. Once electricity was put to use we adapted many of the same control features we were using with steam. As we created more complex machines they became harder to control. Early cars were relatively simple. To start you stood in front attached a handle to the engine and cranked. After enough people broke their arms, starters were invented. Today there are so many things happening in a car at once that you could not carry enough people to control it all at once.
It is getting harder to find products now that don't contain some form of computer chip. Besides automobiles, refrigerators, furnaces, even greeting cards all contain chips. These chips are forms of microcontrollers. Some of these chips are programmed once and they perform their function forever others have the ability to be erased and reprogrammed. No matter how complex they become they all serve the same function which is to make something happen when we want.