“Its easy to complain about not having shoes, until you meet a man with not feet” Unknown

Lets review

• Pick one word from your reading guide. • On the left side of your paper create a drawing or

image that describes that word. YOU CAN NOT USE WORDS***

• Pass your spiral to your elbow partner.• Partners use your reading guide to try to guess

the words that go with their pictures.• Pass the spirals back and see how you did. Make

sure to explain yourself to your partner.

Essential Questions1. What are systems?

2. How do they respond to change?

A. What is system?

1. A system is a set of components that function and interact in some regular way.

Ex: human body2. Key components of a system include: inputs (aka flows or throughputs) and outputs.

B. How do systems respond to change?

Think about the word FEEDBACK… Together with your partner give develop a definition for feedback…

True definition: any process that increases or decreases a change to a system.

B. How do systems respond to change?

Two types:1. Negative Feedback loop: causes a system to

change in the opposite direction from which it is moving. Ex: thermostat

2. Positive Feedback loop: causes a system to change further in the same direction.

C. Other things to consider…

• Time Delays can occur between the input of a feedback stimulus and the response to it. (ex: Replanting a forest that has been cut down)

• Time delays can also allow a problem to build slowly until it reaches a threshold level or tipping point. (nothing else can be done)

• Synergistic interaction or synergy: occurs when two or more processes interact so that the combined effect is greater than the sum of their separate effects.

Personal Take away…

Everything we do affects someone or something in the environment in so way…

For example:

Agriculture: cut down trees, increase erosion, flooding, and loss of biodiversity.

Pick two words…

Create a riddle or an analogy for each word and put it on the opposite page of your notebook. Tomorrow we will be looking at these in class so if you don’t finish make sure you finish it for homework.