Steam power works on the principle that heating water to the point of vaporization causes a build-up of pressure, because the vaporized water takes up more space than liquid water. Gases, liquids and solids are all held together by different molecular forces.Continue Reading
HowStuffWorks explains that the process of heating water to a temperature that causes it to vaporize causes a build-up of pressure in an enclosed space. One example of this is heating up a can of soup over a fire without ventilating it. As the liquid in the soup starts to evaporate, the molecules become more excited. However, since the molecules are locked in an enclosed space, there is a build-up of pressure due to the increased molecular motion. Eventually, the pressure becomes too much for the can to handle, and it explodes. This is the same force at work when dealing with steam-power machines.
Greek mathematician Hero was one of the first people to theorize the use of steam technology. Hero came up with his theory during the second half of the first century. Despite his theory, the first steam-powered engine was not built for another 1,600 years. The very first steam engine was developed to help drain water from mines and gardens.Learn more about Motion & Mechanics