emptiness vs empty space

emptiness

noun
  • The state or feeling of being empty. 

  • A void; a nothingness; something lacking existence. 

  • A nonexistence; a lack of existence. 

empty space

noun
  • A feeling of longing for someone or something that is gone; a sense of a thing's absence. 

  • Vacuum; a space containing nothing at all 

  • An unoccupied space where something may be stored 

  • An unoccupied area or volume. 

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