# Homeostasis Walter Cannon 1932 The Wisdom of the Body Jame Lovelock ~1969 Gaia hypothesis (Lovelock, J.E.; Margulis, L. (1974). "Atmospheric homeostasis.

## Presentation on theme: "Homeostasis Walter Cannon 1932 The Wisdom of the Body Jame Lovelock ~1969 Gaia hypothesis (Lovelock, J.E.; Margulis, L. (1974). "Atmospheric homeostasis."— Presentation transcript:

Homeostasis Walter Cannon 1932 The Wisdom of the Body Jame Lovelock ~1969 Gaia hypothesis (Lovelock, J.E.; Margulis, L. (1974). "Atmospheric homeostasis by and for the biosphere- The Gaia hypothesis". Tellus 26 (1): 2–10.GaiaTellus

Draw a causal lop diagram describing a self regulating component of the human body.

Example Draw a causal loop diagram to describe the following: The sun becomes brighter causing Earth to warm to a new equilibrium temperature. sunlight Earths mean Temperature Emitted infrared energy + - - +

Coffee System Tc TRTR The hotter the coffee is The faster it cools Tc-T R Cooling Rate The higher the cooling rate The colder the coffee Cooling Rate Tc-T R + -

Coffee System Tc TRTR The hotter the coffee is The faster it cools Tc-T R Cooling Rate The higher the cooling rate The colder the coffee - + - = -

Negative connection The higher the cooling rate The colder the coffee Cooling Rate Tc-T R - Tc TRTR

Positive connection The hotter the coffee is The faster it cools Tc-T R Cooling Rate + Tc TRTR

Negative feedback loop Tc TRTR The hotter the coffee is The faster it cools Tc-T R Cooling Rate The higher the cooling rate The colder the coffee - + - = -

Cools with a characteristic time constant, minutes

Homeostasis is internal balance

Equilibrium

Stable equilibrium (negative feedback)

Unstable equilibrium (positive feedback),

Perturbations Small changes that disturb a system from its equilibrium state. Hot Plate

A simple Earth Heating rate TETE

A simple Earth Heating rate TETE Albedo Absorbed solar Complete the system diagram

Daisy World simulation

Daisy World Average surface Temp Daisy coverage TsDaisies Ts Daisies Albedo

Daisy World Average surface Temp Ts Daisies Daisy coverage TsDaisies

Daisy World Average surface Temp Ts Daisies Daisy coverage TsDaisies albedo P1P1 P1P1 Ts Daisies albedo P2P2 P2P2

Daisy World Model

Download ppt "Homeostasis Walter Cannon 1932 The Wisdom of the Body Jame Lovelock ~1969 Gaia hypothesis (Lovelock, J.E.; Margulis, L. (1974). "Atmospheric homeostasis."

Similar presentations