Diffusion is a time-dependent random process causing a spread in space.

Diffusion may also refer to:

Physical sciences

• Molecular diffusion, spontaneous dispersion of mass (distinct from migration, caused by an external force)

• Conduction of heat

• Momentum diffusion

Diffusion equation

• Heat equation

• Schrödinger equation

• Eddy diffusion

More specific meanings

• Anomalous diffusion, the movement of particles from a region of lower concentration to a region of higher concentration

• Diffusion MRI

• Diffusion (acoustics), sound waves

• Atomic diffusion

• Brownian motion

• Collective diffusion

• Facilitated diffusion

• Effusion of a gas through small holes

• Gaseous diffusion

• Itō diffusion

• Knudsen diffusion of particles from very small containers

• Osmosis, the movement of molecules through a membrane

• Reverse osmosis, a process to separate unwanted particles from a fluid

Photon diffusion, an optical effect

• Diffuse reflection, the reflection of light from an uneven or granular surface

• Reverse diffusion, the movement of particles from a region of lower concentration to a region of higher concentration

• Rotational diffusion

• Self-diffusion

• Surface diffusion

• Thermodiffusion

Social sciences

• Demic diffusion of a population to a new area (uninhabited or already inhabited by others)

Cultural diffusion of culture ideas and items within a single culture or from one to another

• Diffusion of innovations between cultures or societies, or within one

• Lexical diffusion of sound changes across a language

Technology

• Diffusion (cryptography), the spreading of influence of bits in a cipher

• Error diffusion in image processing

• Diffusion model in machine learning media or text generation.

Other uses

• Diffusion (business), the process by which a new idea or new product is accepted by the market

• Diffusion line, a secondary line of merchandise created by a high-end fashion designer

• Diffusion Pharmaceuticals, a drug development company

• Diffusion process, in probability theory the solution to a stochastic differential equation

• Diffusion of responsibility

• Society for the Diffusion of Useful Knowledge

• Diffusion Science Radio Show, a science radio show and podcast on 2SER in Sydney

• Diffusion Records, an independent record label

• Sound diffusion, a performance practice in electronic music

See also

• Diffuser (disambiguation)

• Diffuse nebula

• Migration (disambiguation)