bright side vs buoyancy

bright side

noun
  • A consoling aspect of a difficult situation. 

buoyancy

noun
  • Resilience or cheerfulness. 

  • The ability of an object to stay afloat in a fluid. 

  • The upward force on a body immersed or partly immersed in a fluid. 

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