Space Systems!

If you spend a few hours outside your house, you will discover that your environment is a complex collection of things that work together. Sometimes they might help to create a beautiful day. At other times, they can unleash frightening storms, lightning and tornadoes. Scientists call these things systems because, as they operate through time and space, they can also cause matter and energy to move around within the Earth, its atmosphere, and its biosphere. Like the gears in a watch, some systems can be divided into what are called 'sub-systems', which exchange energy and mass to make up the overall larger system. Every system usually has one or more inputs and one or more outputs.

Introduction: Your family car is a system of mechanical, electrician and chemical parts that work together to convert chemical energy locked up inside a fuel (gasoline) into mechanical energy (motion). Your family car can also be divided into smaller, separate parts that are also systems. These sub-systems help the car to use electricity to run its many parts (the electrical system), or keep the engine cool so that it doesn't break (the cooling system). Each of these sub-systems has its own input and output. For example, the input to the electrical system is the car's battery. The output to this system is a variety of devices that make the motor run properly ( for instance the electrical sparks in the spark plugs)

A Familiar System The most well known system to most students is the atmosphere. It receives inputs from the sun in the form of solar energy and from the ground in the form of heat. It produces as its 'output' a number of phenomena such as weather, surface erosion, winds, and evaporation. We can take one of these outputs, such as evaporation, and see how it is caused by a 'sub-system' called the Water Cycle. Ocean water is heated and evaporates into the atmosphere. This moist air condenses into precipitation (for example rain or snow) and falls to the ground, where it is returned to the ocean in rivers. We can look at each of these steps in the Water Cycle and see that they can also be further divided into even smaller systems that depend on them. Fresh water flowing on the land, for instance, is an important source of energy and sustenance for many living systems that depend on rivers and creeks for nourishment and for transportation. [Click the images to learn more about them at another web site - but please come back!!!]

Other Systems: Most natural systems tend to be hard to study because their components are usually hidden from direct view, or are invisible to the normal senses. They can be too small to see, or sometimes so big that you cannot see the whole thing all at once to see it working. A common watch looks simple from the outside, but as a system it is actually complicated.

[Left Image] A battery or spring provides the energy (input) to drive the gears that help you tell time (output). What happens inside the watch between the battery you can replace, and the dials on the front, is hidden from view.

[Right image] The electronic circuitry inside your TV set is also a 'mysterious' collection of pieces that don't tell us directly exactly what they are doing - only the engineer that designed the circuit really understands all of the details!

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