the last time earth's magnetic field reversed was 780,000 years ago.
how long ago was the last time earth's magnetic field reversed?
780,000 years ago
earth's magnetic field is not constant—the strength of the field and the location of its poles vary. moreover, the poles periodically reverse their orientation in a process called geomagnetic reversal. the most recent reversal occurred 780,000 years ago.









































section::::important uses and examples of magnetic field.:record-high fields.









































the largest magnetic field produced over a macroscopic volume is 2.8 kt 









































(vniief in sarov, russia, 1998).









































magnetars have the strongest known magnetic fields of any naturally occurring object, ranging from 0.1 to 100 gt (10 to 10 t). see orders of magnitude (magnetic field).









































section::::important uses and examples of magnetic field.:rotating magnetic fields.
magnetic field
bullet::::- "spheromak:" very similar to a field reversed configuration, a semi-stable plasma structure made by using the plasmas' own self-generated magnetic field. a spheromak has both a toroidal and poloidal fields, while a field reversed configuration only has no toroidal field.









































bullet::::- "reversed field pinch:" here the plasma moves inside a ring. it has an internal magnetic field. moving out from the center of this ring, the magnetic field reverses direction.









































section::::methods.:inertial confinement.
fusion power