 Kinematic dynamo theory was mainly a matter of trying different flow geometries and testing whether such geometries could sustain a dynamo.The first "self-consistent" dynamo models, ones that determine both the fluid motions and the magnetic field, were developed by two groups in 1995, one in Japan and one in the United States.The latter received attention because it successfully reproduced some of the characteristics of the Earth's field, including geomagnetic reversals.