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Based upon:

Based upon: Kelly, Kevin. 1989. Simple words about the new science of complexity: A talk with George Cowan. Whole Earth Review 63 (Summer 1989): 94-97. WAYS OF LOOKING AT THE WORLD.

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  1. Based upon: Kelly, Kevin. 1989. Simple words about the new science of complexity: A talk with George Cowan. Whole Earth Review 63 (Summer 1989): 94-97.

  2. WAYS OF LOOKING AT THE WORLD • Humans tend to perceive things either holistically (as irreducible wholes) or reductionistically (as collections of simpler components) • Both views have their merits • However, we must also consider the INTERACTIONS between the components SYSTEMS THEORY

  3. SYSTEMS • ‘systēma’ (Gr.) – “organised whole” • a set of interacting or interdependent components forming an integrated whole • many types and scales of systems, from subatomic particle interactions in matter, through metabolic systems in cells, up to star systems in the universe

  4. SYSTEMS • Ludwig von Bertalanffy(1901-1972) • was frustrated by reductionist thinking • sought a unifying theory that would cover philosophy, psychology, physics, and chemistry

  5. General Systems Theory • one general organising theory to unite many different areas • central tenet: all systems, however different, have similar underlying organising principles • General Systems Theory extends from very simple nonliving systems (e.g., thermostats) to complex living systems (e.g., organisms, societies, institutions & cultures)

  6. SYSTEMS open systems: • exchange matter and energy with their surroundings -> most systems are open (living organisms, heat engines, etc.) closed systems: • exchange energy, but not matter, with their surroundings (e.g., computer programs, planet Earth)

  7. ALL SYSTEMS HAVE… Structure: components that are directly or indirectly related to each other Behavior: processes that transform inputs into outputs (material, energy or data);

  8. ALL SYSTEMS HAVE… Interconnectivity: their parts and processes are connected by structural and /or behavioral relationships Boundaries: natural or defined limits which determine which parts are inside the system and which parts are outside

  9. A PROBLEM ARISES!

  10. 1977 Apple II Desktop Mid-1980s Desktop PC

  11. ATTEMPTS TO DESCRIBE COMPLEX SYSTEMS IN TERMS OF THEIR SUBSYSTEMS, SHOWING HOW THE PROPERTIES OF THE SUBSYSTEMS ARISE FROM THE INTERACTION OF THE SUBSYSTEM “PARTS”

  12. “EMERGENT PHENOMENA” “EMERGENT PROPERTIES”

  13. e.g., • Interaction of wind with the surface of the ocean results in WAVES • interaction of lunar gravity with the surface of the ocean results in TIDES

  14. Interaction of water with the surface of the sand results in RIPPLES

  15. Interaction of win with the surface of the sand results in DUNES and RIPPLES

  16. Computer simulation: • THE FORMATION OF SAND RIPPLES BYWATER WAVES IN A UNIFORM CURRENT • The model contains: • topography • grain size distribution • grain volume • compaction • acoustic impedance • Unpublished mathematical model, 2005 • Dr. Peter Staelens (Brugge, Belgium)www: www.dotocean.eucontact: peter@dotocean.eu

  17. AN EARLY EXAMPLE (1990s) FORETELLING CURRENT SYSTEMS:

  18. Example: Seattle Traffic Flow Map • http://www.wsdot.wa.gov/traffic/seattle

  19. IMPLICATIONS:

  20. Metastable ecosystem: Freshwater marsh (e.g., Cataraqui Marsh near Kingston, ON) • Appears very stable and unchanging • Little evidence of growth or renewal except for seasonal change from summer green to winter brown • Actually one of the most productive ecosystems on the planet -> • Rapid cycles of growth, senescence, decomposition -> high energy flowsand quick cycling of materials

  21. Wetlandnutrientcycling and storage (yellow box) Wetland ecosystem components (boxes) Wetland ecosystem processes (arrows) From Hossler et al. 2011

  22. SHRIEK!!! SHRIEK!!! SHRIEK!!! SHRIEK!!! : E.g. Audio feedback – Microphone picks up sound -> Amplifier makes it louder -> Speaker broadcasts it -> Microphone picks up sound -> Amplifier makes it louder -> Speaker broadcasts it -> Microphone picks up sound -> Amplifier makes it louder -> Speaker broadcasts it ->

  23. E.g. Positive feedback in a natural system: Greenhouse gases in the atmosphere and climate change

  24. UNCHECKED POSITIVE FEEDBACK LOOPS MAY TEND TO DESTROY THE SYSTEM THAT THEY ARE A PART OF

  25. : E.g. HEATER AND THERMOSTAT • The heater kicks on, heating up a room • Heat, the output of the heater, serves as input to the thermostat. • At a certain critical temperature, the thermostat tells the heater that the room is warm enough. • The heater, receiving this feedback through an electrical connection, shuts itself off. • After a while, the thermostat notices that the room has cooled to a specific temperature, and notifies the heater. • The heater kicks on again. • The information traveling from the heater to the thermostat and back again is a negative feedback loop. Thermostat Heater

  26. E.g. Negative feedback in a natural system: Cycles in lynx and hare populations

  27. NEGATIVE FEEDBACK LOOPS MAY TEND TO STABILIZE THE SYSTEM THAT THEY ARE A PART OF

  28. INTERACTIONS BETWEEN NEGATIVE AND POSITIVE FEEDBACK LOOPS IN A SYSTEM CAN RESULT IN DYNAMIC EQULIBRIUM

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