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 Additional
Workshop Activities
Introduction
Water In A Cup
Card Game Systems
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INTRODUCTION
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It is most desirable to do activities that are found in EarthComm
chapters and illustrate key concepts, lesson design features,
and other aspects of the program using those activities as examples.
However, in that the concept of systems may be new to some teachers,
it may be useful to illustrate that idea using even simpler and
more common examples than are found in EarthComm activities. To
a degree, this will depend on the workshop presenter's comfort
level with the concept as well.
Below are two system analogies that are very much simplified
and use common materials so that the general components of a system
can be illustrated effectively.
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WATER
IN A CUP
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Materials
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Two plastic cups
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Small plastic tub
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Marker
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Plastic wrap Pin
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Procedure
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Fill the plastic cup half full with water, cover it with
the plastic wrap and place it in the small plastic tub.
Also mark the location of the water level with a marker
or piece of tape. The small tub will catch the water flowing
out in the next two steps so it does not spill on the floor.
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System Analogy
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Characteristic parts and properties of the system:
The plastic cup, plastic wrap, and the water. A property
of this system that can be measured is the water level.
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Boundaries of the system: The boundaries of this
system are easily defined. The boundaries are: the sides
of the glass and the plastic wrap.
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Input and Output: There is no input or output. It
is a closed system with respect to the addition or subtraction
of matter, which is water in this example.
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Remove the plastic wrap and use the pin to poke a small
hole in the side of the cup about one-quarter of the way
up the cup. Water should come out of the small hole. You
have now created an open system, i.e., matter (water) can
be exchanged with the surroundings.
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System Analogy
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Characteristic parts and properties of the system:
The plastic cup, plastic wrap, and the water. The properties
of the cup have been modified. A property of this system
that can be measured is the water level.
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Boundaries of the system: The boundaries are: the
sides of the glass and the plastic wrap.
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Input and Output: There is no input. Because placing
a pinhole in the cup has modified the system, output occurs.
Output is greater than input. As a result the system changes.
The response of the system is for the water level to go
down in the cup. The system is open in that matter (water)
is being removed from the glass and added to the surroundings.
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Fill the second plastic cup with water. Remove the plastic
wrap from the first cup and add water to it to bring the
water level up to the initial starting level.
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System Analogy
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Characteristic parts and properties of the system:
The plastic cup and the water. The plastic wrap has been
removed. A property of this system that can be measured
is the water level.
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Boundaries of the system: The boundaries are: the
sides of the glass.
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Input and Output: There is input and output. Because
placing a pinhole in the cup has modified the system, output
occurs. The water that is being added to the cup is considered
input. To bring the water level back up, the amount of water
being added into the system has to exceed the amount leaving
the system. Input is greater than output.
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Continue to add water to the system so that the water level
does not change.
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System Analogy
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Characteristic parts and properties of the system:
The plastic cup and the water. The plastic wrap has been
removed. A property of this system that can be measured
is the water level.
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Boundaries of the system: The boundaries are the
sides of the glass.
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Input and Output: There is input and output. Because
placing a pinhole in the cup has modified the system, output
occurs. The water that is being added to the cup is considered
input. To keep the water level from changing, the amount
of water leaving the system is equal to the amount of water
entering the system. Output is equal to input. This is an
example of dynamic equilibrium in which the a system is
changing (i.e., water is entering and leaving), yet the
measurable characteristic of the system (i.e., the water
level) remains the same or about the same within limits.
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An Earth System Example: The Earth's atmosphere.
It is in dynamic equilibrium because the energy received
by the Earth from the Sun equals the energy emitted into
space. As long as the energy from the sun is constant, and
the composition of the atmosphere does not change, the Earth's
atmosphere will remain in dynamic equilibrium, and the average
temperature at the surface will remain about the same.
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Poke at least five more holes into the cup.
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System Analogy
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Characteristic parts and properties of the system:
The plastic cup and the water. The plastic wrap has been
removed. The characteristics of the system (plastic cup)
have been significantly altered by the addition of the five
holes. A property of this system that can be measured is
the water level.
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Boundaries of the system: The boundaries are the
sides of the glass.
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Input and Output: There is input and output. Because
placing additional pinholes in the cup has modified the
system, the potential for output has increased. The water
that is being added to the cup is considered input. The
output has been significantly increased and the water level
is changing. Our dynamic equilibrium has been altered which
could lead to detrimental effects.
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An Earth System Example: Continuing with our example
from step 4, if there is a change to the Earth system such
as a change in the Sun's brightness, or in the composition
of the atmosphere, the Earth's dynamic equilibrium could
change, bringing about a change in global climate.
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Alternative Setup: This analogy can also be done
using a large, clear plastic funnel set in a large glass,
which will serve to catch the water. The bottom of the funnel
could be initially closed with plastic wrap and holes could
be punched into the plastic wrap as was done to the plastic
glass.
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CARD
GAME SYSTEMS
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Card games that are familiar to the participants can be used as
analogies to illustrate the attributes of systems. The attributes
of a system and the comparison with card games in general and
with specific examples are given below.
Characteristic parts and properties of the system: In
most card games, there are a certain number of cards that are
dealt to each player and there are usually a specific number of
players. The total number of cards and the players are considered
the system. Each player and the cards they hold are considered
subsystems.
Boundaries of the system: Defining the boundaries of the
system for a card will be specific to the game being played. Examples
of boundaries include: number of cards in the deck; number of
card dealt to each player; the number of points being pursued
in the card game.
Input and Output: Once a card game starts, it is a closed
system. The number of players and cards do not change. However,
at the subsystem level, there is input and output. For example,
in the game 31 each player is given three cards then it is up
to the player to obtain three cards in the same suit whose sum
is 31. To accomplish the task of getting 31, each player systematically
selects one card at a time. This card is added or input into their
hand. Because the system is characterized and defined by the boundary
of three cards, the player must discard or output one card from
their hand. This is an example of dynamic equilibrium card game
in which the a system is changing (i.e., cards are being input
and output), yet the characteristics of the system stay the same
(i.e., three cards).
In the game "Crazy Eights", eight cards characterize
the players' subsystem. The primary goal is to get rid of all
your cards through a process of sequentially playing a card that
matches those on a discard pile. If the player does not have an
appropriate card to play, then they are required to draw from
a pile until they obtain a card they can play. Using a systems
analogy, the overall goal of the game is for the output to exceed
the input of cards. The discard process is the output of cards
from the hand. Drawing from the pile represents the input of cards
into the system. Throughout the game the system or number of cards
is constantly changing. In some cases, the input can greatly exceed
the output so that the player cannot hold all the cards in their
hand. The card system is stressed to the point where it exceeds
the card-holding capacity of the player and cards fall to the
floor.
Feedback: In many card games, the subsystems (players
hands) do not exist in isolation. The way in which the cards are
played are linked or coupled. For example, in a game of gin rummy,
when one player discards a card, the next player reacts to the
action of the first player. Their reaction now becomes an action,
and the first player reacts to that action. As a result of these
couplings, there is feedback between the subsystems. Feedback
is a self-perpetuating mechanism of change and response to that
change. In terms of change and response, natural and social systems
behave in a similar manner.
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AGI's professional development programs for teachers are supported
by generous contributions from corporate contributors of the American Geosciences Institute Foundation, the American
Association of Petroleum Geologists Foundation, and ChevronTexaco.
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