One of Irving Langmuir's classic examples of "pathological science," the so-called Allison effect, falsely claimed to use this phenomenon as the basis for a new method of spectroscopy.  
One of Irving Langmuir's classic examples of "pathological science," the so-called Allison effect, falsely claimed to use this phenomenon as the basis for a new method of spectroscopy.  In its "inverse" version the spin of certain particles can be converted into angular momentum.  It causes an amount of circular birefringence dependent on the Verdet constant of the medium, and its direction is caused by the direction of the magnetic field producing it.  FTP, identify this rotation of a light beam's plane of polarization, discovered by a British scientist who is also the namesake of the unit of capacitance.
One of Irving Langmuir's classic examples of "pathological science," the so-called Allison effect, falsely claimed to use this phenomenon as the basis for a new method of spectroscopy.  
Faraday effect or Faraday rotation (prompt on "magneto-optic effect")