Chris Peterson wrote:Giant magnets? They were never considered to act like magnets.ta152h0 wrote:
one more, considering this is Sunday. Are black holes still considered singularities acting as giant magnets ?
- Perhaps you are thinking of a magnetar or a Dirac string:
http://en.wikipedia.org/wiki/Dirac_string wrote:
<<A Dirac string is a hypothetical one-dimensional curve in space, conceived of by the physicist Paul Dirac, stretching between two Dirac magnetic monopoles with opposite magnetic charges, or from one magnetic monopole out to infinity. The gauge potential cannot be defined on the Dirac string, but it is defined everywhere else. The Dirac string acts as the solenoid in the Aharonov–Bohm effect, and the requirement that the position of the Dirac string should not be observable implies the Dirac quantization rule: the product of a magnetic charge and an electric charge must always be an integer multiple of 2π. The Dirac string is the only way to incorporate magnetic monopoles into Maxwell's equations, since the magnetic flux running along the interior of the string maintains their validity.>>
- However, black holes may possibly have a little "hair":
http://www.scientificamerican.com/article/black-holes-may-have-hair/ wrote: Black Holes May Have "Hair"
Oct 21, 2013 |By Megan Gannon and SPACE.com
<<Astronomer John Wheeler, who coined the term "black hole" nearly 50 years ago, famously said that "black holes have no hair" because of their simplicity. Now "hair" is used as a colloquial term among physicists as a stand-in for any other measure needed to describe a black hole that departs from: their mass, their angular momentum (how fast they spin) and their electric charge. [However,] Thomas Sotiriou, a physicist at the International School for Advanced Studies of Trieste and his colleagues looked at black holes in the context of the equations of scalar-tensor theories of gravity. The researchers found that [such non-Einsteinian] black holes [may] develop scalar "hair" when ordinary matter surrounds them.>>
See: http://www.scientificamerican.com/artic ... have-hair/