Convection as physical process

• Simple mechanism:
  Self-sustained heat transport by macroscopic motion of matter
  in a gravitationally stratified environment
  
• Complex details:
  E.g. on Earth: clouds, weather, climate

Stellar convection

• Heat transport -> temperature stratification
• Transport of matter -> mixing, abundances
• Motion -> broadening and shift of spectral lines,
  Motion -> pressure stratification
• Heat engine -> kinetic energy, waves
• Non-linearity -> structure formation, chaos
• Interaction with magnetic fields (+ rotation) -> dynamo