Few inventions in modern times have had as powerful an impact on our lives as automobiles. They reshaped cities, transformed the design of homes and businesses, reshaped shopping and dining habits, and made possible vacation travel in ways that would have been impossible without them. They brought about new social and recreational activities, such as camping and hunting, that could not have been done before. They allowed people to travel to work and school in cities and towns far from their home, opening up large areas of the country for development and expanding the opportunities available to people to live where they wanted. And they led to the development of mass production techniques that have influenced many other industries.
The scientific and technical building blocks of the automobile date back several hundred years. The first cars were essentially horse-drawn carriages with engines added. During the late nineteenth century, engineers and inventors struggled to find ways to make them more reliable and economical.
Today, most automobiles are powered by a liquid fuel called gasoline or electric motors. The engine converts chemical energy from the fuel into mechanical energy that drives the wheels of the car, which turn and move the vehicle forward or in reverse. The wheels are connected to the axles by suspension systems that allow the car to respond to road conditions, while the chassis and body (analogous to the skeletal structure in the human body) provide support for the different parts of the car and provide safety and comfort for the passengers.