Systems that regulate themselves through feedback loops
The Science of Control and Communication
Cybernetics, coined by Norbert Wiener in 1948, is the study of systems that self-regulate
through feedback. From thermostats to economies, from bodies to ecosystems—cybernetics
explains how systems maintain stability and adapt to change.
SYSTEM
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The Feedback Loop
Sense → Compare → Act → Repeat
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Interactive Thermostat
Experience a negative feedback loop in action. The system works to maintain equilibrium
(homeostasis) around your set point.
72°
Current
Set: 72°
System Balanced
What's happening:
Sensor: Reads current temperature
Comparator: Compares to set point
Controller: Activates heating/cooling
Actuator: Changes the temperature
Feedback: New temperature is sensed
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Types of Feedback Loops
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Positive (Reinforcing)
Amplifies change. Leads to exponential growth or collapse.
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Negative (Balancing)
Dampens change. Maintains stability and equilibrium.
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Oscillating
Cycles between states. Can stabilize or amplify.
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Predator-Prey Simulation
Watch how two interconnected negative feedback loops create oscillating populations (the
Lotka-Volterra model).
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Prey: 50
🐺
Predators: 10
Time →Population
The Feedback Loops:
More prey → More predators (after delay) → Less prey
Less prey → Fewer predators (after delay) → More prey
Result: Continuous oscillation
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Components of a Cybernetic System
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Sensor
Detects current state
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Comparator
Compares to goal
🧠
Controller
Decides action
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Actuator
Makes changes
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Cybernetics in the Real World
Biology: Body temperature regulation, blood sugar control, hormone
feedback
Ecology: Predator-prey dynamics, population limits, resource cycles
Economics: Supply and demand, market corrections, inflation control
Organizations: Management by objectives, quality control, performance
reviews
Technology: Cruise control, autopilot, smart home systems, AI learning