The ability to create, to imagine, invent, and improve
is a characteristic given to humankind alone. The potential for creativity
allows us to take simple, smaller pieces and combine them to make something more:
more beautiful, more inspiring, or more useful. This skill allows us to shape the world around us.
Our history books are full of men and women who used their creative abilities to design things
that would change the world. Let's explore the simple machines that left their mark on history.
There are six basic, simple machines that humans have used for thousands of years.
They are wedges, levers, inclined planes, wheels and axles, pulleys, and screws.
This tool is a wedge. Do you see how it is thick on one end and tapers to a thin edge on the other?
It can be used for tightening, splitting, or lifting objects,
and often has a handle attached to make it easier to use. Levers consist of a rigid
beam resting on and pivoting around a fulcrum. A teeter-totter on a playground is a type of lever.
Levers allow us to lift much heavier loads than we can by ourselves. The next simple machine
is called an inclined plane, but you might know it better as a ramp. This machine
allows us to move things from one height to another. Next, we come to wheels and axles.
The invention of the wheel allowed for the invention of the pulley.
A pulley is a wheel that carries a chain, rope, or belt around its rim. It can be used to lift
heavier weights than a person can lift on his or her own. Last, but not least, is a common screw.
The ridges running around the body of the screw allow us to use screws for tightening, fastening,
or lifting objects. You may think of machines as modern inventions, but they have actually
been around for a very long time, making work easier and more complex projects possible. That
is their main purpose. Machines are created to help us accomplish work. You may think that these
inventions are too common sense and uncomplicated to have made much difference in people's lives
but consider the way our lives would be different without the wheel or the screw. Would we be
able to build houses as easily and sturdily without metal screws to hold the wood together?
As another example, imagine a farmer, long ago, trying to transport his harvest to market.
One way he could get his harvest there is by carrying it himself, but one person can only
carry so much weight, and it would take the farmer a lot of trips and effort to move all of his crops
by hand. The invention of the wheel and axel, one of the most important simple machines of all time,
revolutionized the way humans moved objects and transported themselves around. This simple,
life-changing machine allowed and still allows the farmer to accomplish more work with less effort.
One area where simple machines have made a big difference is in construction. People
have been constructing buildings such as churches, tombs, homes, and palaces for thousands of years
and over time, humans have designed many machines to make the construction of these buildings
easier and safer. Can you imagine trying to build the Eiffel Tower in France
over one thousand feet tall with nothing but your hands? It would be impossible.
Or, consider the Egyptian pyramids. These massive structures couldn't have been made without the use
of tools and simple machines. The Great Pyramid of Giza alone is made of more than two million
immense stone blocks each weighing more than four thousand pounds. We don't know exactly how these
pyramids were constructed, but researchers do know that the Egyptians used simple machines such as
ramps and pulleys to get the stones into place and small tools such as chisels to shape the stones.
Chisels, ramps, and pulleys. These are all types of simple machines. Archaeologists
are still studying these sites to discover more details about this amazing feat and the
tools and machines that were used to make it possible. If you look around your house,
it's likely that you will find examples of some or all of these simple machines. Humans are
still using these inventions thousands of years after they were first created because they are
powerful tools we have to make work easier. We use simple machines every day. Sometimes, these basic
machines are combined to create a more complex machine capable of doing more work. These machines
allow us to do and build incredible things. Simple machines make the impossible possible.