The Simple Six Machines are an elementary concept in mechanical physics. Each of these machines, some with truly antique origins, is a basic means of multiplying force. Although the concept is somewhat dated, it is still illustrative of basic mechanical concepts, and virtually every machine in use today is, in reality, an assembly of simple machines.
Identification
A simple machine is a device that changes either the direction or magnitude of applied force. The term is commonly used to describe six devices known to Renaissance mechanical physics. In theory, all complicated machines are composed of parts derived from the Simple Six. However, not all simple machines were included. The hydraulic press, for example, is strictly speaking a simple machine, but not part of the Simple Six.
Types
The Six Simple Machines are the inclined plane, lever, pulley, screw, wedge and the wheel and axle. The lever, pulley and wheel all work through the equilibrium of torques (or twisting). For example, a pulley uses rotational motion to change the direction of force (twisting it), gaining efficiency. The plane, wedge and screw are dependent on the vector resolution of forces. An example would be the inclined plane, where one trades the amount of energy required to lift an object for increasing the distance it must travel.
Function
What simple machines all have in common is that they create mechanical advantage. They can all be used to increase the output of force. None of these devices actually create energy, but instead transforms it into more usable directions.
History
The idea of the simple machine began with the famous Greek philosopher Archimedes, who discovered the principle of mechanical advantage as applied to the lever, and also studied the screw and pulley. Heron of Alexandria later added the wedge to the ultimate list of six. During the Renaissance, the plane, lever, screw, pulley and wheel and axle were studied. It was Galileo who added the wedge back to the list to form the Simple Six.
Considerations
There is a lot of dispute about whether the Simple Six machines are even six in the first place, aside from the lack of inclusion of hydraulic devices. For example, some scientists insist that the wedge is merely a moving inclined plane.
