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polarizationmore about polarization


  2  definitions  found 
  From  Webster's  Revised  Unabridged  Dictionary  (1913)  [web1913]: 
  Polarization  \Po`lar*i*za"tion\,  n.  [Cf.  F.  polarisation.] 
  1.  The  act  of  polarizing;  the  state  of  being  polarized,  or  of 
  having  polarity. 
  2.  (Opt.)  A  peculiar  affection  or  condition  of  the  rays  of 
  light  or  heat,  in  consequence  of  which  they  exhibit 
  different  properties  in  different  directions. 
  Note:  If  a  beam  of  light,  which  has  been  reflected  from  a 
  plate  of  unsilvered  glass  at  an  angle  of  about  56[deg], 
  be  received  upon  a  second  plate  of  glass  similar  to  the 
  former,  and  at  the  same  angle  of  incidence,  the  light 
  will  be  readily  reflected  when  the  two  planes  of 
  incidence  are  parallel  to  each  other  but  will  not  be 
  reflected  when  the  two  planes  of  incidence  are 
  perpendicular  to  each  other  The  light  has  therefore, 
  acquired  new  properties  by  reflection  from  the  first 
  plate  of  glass,  and  is  called  polarized  light,  while 
  the  modification  which  the  light  has  experienced  by 
  this  reflection  is  called  polarization.  The  plane  in 
  which  the  beam  of  light  is  reflected  from  the  first 
  mirror  is  called  the  plane  of  polarization.  The  angle 
  of  polarization  is  the  angle  at  which  a  beam  of  light 
  must  be  reflected,  in  order  that  the  polarization  may 
  be  the  most  complete.  The  term  polarization  was  derived 
  from  the  theory  of  emission,  and  it  was  conceived  that 
  each  luminous  molecule  has  two  poles  analogous  to  the 
  poles  of  a  magnet;  but  this  view  is  not  now  held. 
  According  to  the  undulatory  theory,  ordinary  light  is 
  produced  by  vibrations  transverse  or  perpendicular  to 
  the  direction  of  the  ray,  and  distributed  as  to  show  no 
  distinction  as  to  any  particular  direction.  But  when 
  by  any  means  these  vibrations  are  made  to  take  place 
  in  one  plane,  the  light  is  said  to  be  plane  polarized. 
  If  only  a  portion  of  the  vibrations  lie  in  one  plane 
  the  ray  is  said  to  be  partially  polarized.  Light  may  be 
  polarized  by  several  methods  other  than  by  reflection, 
  as  by  refraction  through  most  crystalline  media,  or  by 
  being  transmitted  obliquely  through  several  plates  of 
  glass  with  parallel  faces.  If  a  beam  of  polarized  light 
  be  transmitted  through  a  crystal  of  quartz  in  the 
  direction  of  its  axis,  the  plane  of  polarization  will 
  be  changed  by  an  angle  proportional  to  the  thickness  of 
  the  crystal.  This  phenomenon  is  called  rotatory 
  polarization.  A  beam  of  light  reflected  from  a  metallic 
  surface,  or  from  glass  surfaces  under  certain  peculiar 
  conditions,  acquires  properties  still  more  complex,  its 
  vibrations  being  no  longer  rectilinear,  but  circular, 
  or  elliptical.  This  phenomenon  is  called  circular  or 
  elliptical  polarization. 
  3.  (Elec.)  An  effect  produced  upon  the  plates  of  a  voltaic 
  battery,  or  the  electrodes  in  an  electrolytic  cell,  by  the 
  deposition  upon  them  of  the  gases  liberated  by  the  action 
  of  the  current.  It  is  chiefly  due  to  the  hydrogen,  and 
  results  in  an  increase  of  the  resistance,  and  the  setting 
  up  of  an  opposing  electro-motive  force,  both  of  which  tend 
  materially  to  weaken  the  current  of  the  battery,  or  that 
  passing  through  the  cell. 
  From  WordNet  r  1.6  [wn]: 
  n  1:  the  phenomenon  in  which  waves  of  light  or  other  radiation 
  are  restricted  in  direction  of  vibration  [syn:  {polarisation}] 
  2:  the  condition  of  having  or  giving  polarity 

more about polarization