Interesting Facts About Simple Machines

All machines, no matter how complex, are built out of combinations of the six simple machines, like the pulley.

One of the most striking differences between humans and other animals is the human use of machines. Trains, cars and airplanes enable travel over great distances. Gigantic construction machines help to build enormous buildings and bridges. Subtle complicated machines like clocks keep track of time. Human lives in almost every way either depend upon or involve interacting with machines. Yet despite their great variety, all of these different machines are just different combinations of the six simple machines.

Types

The lever is a simple bar attached to a pivot point that it is able to rest on. The see-saw is an example of a lever, as is the crowbar. The inclined plane, a scientific term for a ramp, is another simple machine. The wedge is basically a moving inclined plane. It is a hunk of strong material thick at one end and thin at the other. Chisels, axes, knives and doorstops are all wedges. A screw is a sort of circular inclined plane. It is a plane that spirals around a cylinder. Screws are often used to hold wooden objects in place. Wheels are simple machines. Pulleys are wheels with ropes around their rims.

Archimedes

Archimedes of Syracuse was an ancient Greek scientist and inventor. Though he did not invent the simple machines, he did much of the early research and development of them. The lord of Syracuse challenged him to move a ship, by himself, that normally took many laborers to move. Using a large collection of levers and pulleys, he succeeded. He also used levers and pulleys to create a weapon called the Claw of Archimedes to protect his home city. It was a primitive crane that upended the ships of attacking navies. Besides these accomplishments, he used simple machines to irrigate crops and supply cities with fresh water.

Simple Machines as Milestones in History

The wheel is one of the biggest technological innovations in human history, according to John H. Lienhard of the University of Houston. Prior to about 3500 B.C.E., all machines were capable only of linear motion: After traveling a certain distance, they had to stop and be reset. With the near-simultaneous invention of the potter's wheel and the vehicle wheel, technology was changed forever. Stone axes, a very primitive form of wedge, are amongst the oldest inventions of humankind. It is thought that the giant blocks used to build the pyramids of Egypt were lifted into place by inclined planes.

Function

All simple machines either alter the directions of forces applied to them or multiply their effects. A lever can be used to lift great weights. Pushing a great distance down on a long lever arm can allow you to lift a great weight up on the other arm if it is closer to the pivot than you are. Pulleys can allow you to pull on a rope in one direction and move a load along a different direction. Ramps do most of the work of holding heavy objects up. Wheels transform turning motions into straight line motion. Wedges turn a force pushing them down into a force that spreads things to the sides. Screws lift things they bite into up over themselves.

Significance

Simple machines are most significant for the modern world because they form complex machines. It was by the development of the six simple machines that the creation of all of the modern world's devices became possible. Without simple machines, the existence of important sciences like modern medicine would be impossible.

References

• California State University Northridge: Simple Machines
• Drexel University: Archimedes
• Vigyan Prasar Science Portal: Archimedes
• Minnesota State University: Stone Axes
• California State University Long Beach: Simple Machines

Resources

• University of Virginia: Compound Machines