polarisation

noun4

1. •
   The production or the condition of polarity.
2. •
   The grouping of opinions into two extremes.

   • What frazzled pollsters, surly op-ed pages, snarling cable talkfests and issue-starved candidates for office need is a fresh source of hot-eyed national polarization. — 2004
3. •
   The production of polarized light; the direction in which the electric field of an electromagnetic wave points.
4. •
   The separation of positive and negative charges in a nucleus, atom, molecule or system.