dynamo

(noun)

A mechanism by which a celestial body such as Earth or a star generates a magnetic field over astronomical timescales via a rotating, convecting, and electrically conducting fluid.

Examples of dynamo in the following topics:

  • Geomagnetism

    • If Earth's dynamo shut off, the dipole part would disappear in a few tens of thousands of years.
    • Electric currents induced in the ionosphere generate magnetic fields (ionospheric dynamo region).
    • Shorter time scales mostly arise from currents in the ionosphere (ionospheric dynamo region) and magnetosphere, and some changes can be traced to geomagnetic storms or daily variations in currents.

  • Different Types of Currents

    • Direct current is produced by sources such as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type.

  • Dunkirk and Vichy France

    • The Dunkirk evacuation, code-named Operation Dynamo, also known as the Miracle of Dunkirk, was the evacuation of Allied soldiers from the beaches and harbour of Dunkirk, France, between 26 May and 4 June 1940, during World War II.