1.2 Systems and Models

Question 1

Model

Answer 1

a set of components that function together and form and interconnected complex whole

Question 2

Systems

Answer 2

• On many scales; from single cells to the entire biosphere.
• Tangible or abstract
• ‘Natural’ or human-made

Question 3

Open systems

Answer 3

Exchange of energy AND matter with surroundings
Eg.
- Cells (co2-o2)
Forest ecosystems (h2o –> 02 released)
Every natural system below the level of Earth itself

Question 4

Closed system

Answer 4

Exchange of energy but NOT matter with surroundings.
Eg.
- Global systems (Hydrological , Carbon and Nitrogen cycles, asteroids)
- Artificial systems (Mesocosmos)
- Biosphere 2 (Arizona)

Question 5

Isolated system

Answer 5

Exchange of neither energy or matter
- doesn’t exist
- Except maybe the whole universe.

Question 6

Modelling systems

Answer 6

The purposes of enabling us to better understand and predict the behaviour of systems:

Understanding is gained by varying inputs, changing processes, and observing outputs.
- Can’t do in reality (Geological systems)
- More efficient (Genetic inheritance)

Predictions are made by inputting data, simulating processes, and recording the outputs.
- Weather

Question 7

Issues with models

Answer 7

All models are imperfect
1. Never have sufficient data
2. Understanding of processes (Reality is MAD complicated) (Unpredictable)

Chaos

All models are simplifications
1. compress information
2. exclude information

Models we build limits define how we understand
1. create a lens
2. impact the way we view the world (maps)

Question 8

Inputs

Answer 8

Flows enter
eg. Physical –> water entering an ecosystem/ –> Solar energy for photosynthesis

Question 9

Processes

Answer 9

Act on inputs
- chemical energy into heat energy (respiration)
- the process of teaching = Information to the student.

Question 10

Outputs

Answer 10

Flows leave
Animals eat –> release energy –> heat waste

Question 11

The Gaia Hypothesis

Answer 11

James Lovelock 1972
- Life on Earth creates a self-regulating system.
- Adopted as a model
- Oxygen supporting life
- Methane regulating temp
Human activity have exceeded the global parameters in which the Earth can self-regulate.

Question 12

Transfers

Answer 12

Movement without a change in form, state, or chemical composition.

Eg.
- water flowing down a river (matter)
- ocean current (heat + energy)
- animal migration (matter + energy)

Question 13

Transformations

Answer 13

Involves form state, and chemical composition.

Eg.
- combustion of fossil fuels (heat –> chemical energy)
- photosynthesis (light –> chemical)
- respiration
- methane production
- decomposition.