Course 4 Astrophysical dynamos

摘要: Publisher Summary This chapter reviews that the dynamo theory is relatively young: ability of a flow conducting fluid to maintain magnetic field was conjectured 90 years ago. Both physical and mathematical aspects are often complicated may seem unnatural an excessively sceptical observer. However, need for action fields Earth Sun so evident paradigm has been very widely accepted planets stars. The situation different with other astrophysical objects—accretion discs, galaxies galaxy clusters. It discusses any recent developments in arise from extensive numerical simulations whose complexity approaches, many respects, laboratory experiment. Therefore, experiments be interpreted same care caution as or astronomical observations. also describes approach quantifying morphology structures based on Minkowski functionals. difficult understand outcome models, experiments, observations without range simplified analytical models. explosive development approaches dynamos, growth computing power available, resulted reduced interest turbulent flows can drive large small-scale but produced by them controlled mechanism rather than initial field. In this sense, properties system unimportant long it provide suitable seed dynamo.