discontinuity vs separation

discontinuity

noun
  • A lack of continuity, regularity or sequence; a break or gap. 

  • a subterranean interface at which seismic velocities change 

  • A point in the range of a function at which it is undefined or discontinuous. 

separation

noun
  • An interval, gap or space that separates things or people. 

  • Departure from active duty, while not necessarily leaving the service entirely. 

  • An agreement legalizing such an arrangement. 

  • An object that separates two spaces. 

  • The act of disuniting two or more things, or the condition of being separated. 

  • The act or condition of two or more people being separated from one another. 

  • The place at which a division occurs. 

  • The act or condition of a married couple living in separate homes while remaining legally married. 

How often have the words discontinuity and separation occurred in a corpus of books? (source: Google Ngram Viewer )