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Physical Sciences
Thermodynamics
1822
Intermediate

Heat Equation

ut=α2u\frac{\partial u}{\partial t} = \alpha \nabla^2 u

Temperature changes proportionally to how curved the temperature distribution is—heat flows from hot to cold.

By Joseph Fourier

Physical Sciences
Heat Equation
1822 · Joseph Fourier
Human Reviewed
84%

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Why it matters: Enabled thermal engineering, climate modeling, and financial mathematics (Brownian motion).

Discoverers: Joseph Fourier (1822)

What does it mean?

Temperature changes proportionally to how curved the temperature distribution is—heat flows from hot to cold.

Why should I care?

Enabled thermal engineering, climate modeling, and financial mathematics (Brownian motion).

Equation Compass

West — History

South — Derivations

Variables & Units

SymbolNameUnitMeaning
uuTemperatureTemperature field
ααDiffusivitym²/sThermal diffusivity
ttTimeTime

Worked Example

Rod ends at 0°C and 100°C reach steady linear temperature profile.

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Equation Universe

Heat Equation

ut=α2u\frac{\partial u}{\partial t} = \alpha \nabla^2 u

Real-world impact

Life sciences

Mathematical models drive medicine and biotech.

Photo: Unsplash — laboratory

Temperature changes proportionally to how curved the temperature distribution is—heat flows from hot to cold.

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