1.2: Systems and Models Flashcards
What is a system?
a set of components that function together and form an interconnected, complex whole
open systems
exchange energy and matter with their surroundings
open system examples
- Your cells
- Forest ecosystems
- Every natural system below the level of Earth itself
Closed systems
exchange energy but not matter with their surroundings
closed systems examples
- Global systems
(hydrological, carbon and nitrogen cycles) - mesocosms (artificial systems)
- Biosphere 2
Isolated systems
exchange neither energy nor matter with their surroundings
Isolated system examples
Don’t really exist but…
The entire universe as technically an isolated system
What is a model?
What is the purpose of a model?
Models are simplified versions of reality
To let us better understand and predict the behaviour of systems
Issues of a model
All models are imperfect; the only perfect model is reality itself:
1. You can never have enough data
2. Our understanding of processes will always be incomplete because reality is complicated
3. All models are simplifications and compress info
4. models can have major impacts on the way we view the world
5. The outputs of models are dependent on the quality of data that is fed into them - GIGO
(Garbage IN = Garbage OUT)
What do all systems have?
Storages
Flows
Inputs
Outputs
Boundaries
Processes
what can stores be?
matter, energy or information
What 2 things do processes do?
they transfer or transform stores from storage to storage
(the stores can be energy, matter of information)
What is the Gaia Hypothesis?
It was created by James Lovelock in 1972
It proposes that life on Earth is a self-regulating system that controls global parameters
(such as temperature, concentrations of gases in the atmosphere and the salinity of seawater)
Essentially, it says that the Earth is like a singular living organism.
What is the main input of a system?
Solar radiation
What is the main output of a system?
Heat (coming from respiration and combustion)
