Science
Magnetic reconnection refers to the merging and separation of magnetic field lines that can occur at neutral points of magnetic fields as those fields change over time. Alternatively, magnetic reconnection refers to changes over time in the topology of magnetic field lines.
Although magnetic reconnection is a simple consequence of
Maxwell's equations, it is usually discussed in connection with plasma physics. Magnetic reconnection has been observed in space plasma and in laboratory experiments. Magnetic reconnection is now known to be responsible for
rapid movements and bursts of light in the aurora borealis, and is believed to be responsible for similar phenomena seen in
solar flares. Magnetic reconnection may also play some role in heating the solar corona.
Pseudoscience
The reality of magnetic reconnection is denied by a motley group of folklorists and amateur physicists who promote an Electric Universe based on
Immanuel Velikovsky's speculations combined with long-refuted scientific conjectures put forth by notable scientists such as
Kristian Birkeland and
Hannes Alfvén. By
misinterpreting some unfortunate remarks by Alfvén, these pseudoscientists denounce magnetic reconnection as pseudoscience.
In particular, the Electric Universe folk often declare that magnetic reconnection violates Maxwell's equations, specifically
Gauss's law for magnetism.
Their argument is based upon the following over-simplification of Gauss's law for magnetism, which is widely repeated even by people who should know better:
Gauss's law for magnetism is equivalent to the statement that the field lines have neither a beginning nor an end: Each one either forms a closed loop, winds around forever without ever quite joining back up to itself exactly, or extends to infinity.
-- Wikipedia's article on
Gauss's law for magnetism, retrieved 12 November 2011.
Although that's a useful white lie when we try to explain magnetic field lines to humanities or engineering majors, it isn't quite true:
Gauss's law for magnetism allows magnetic field lines to begin or to end at neutral points of a magnetic field.