centripetal vs perceptible

centripetal

adj
  • Directed or moving towards a centre. 

  • Directed towards the central nervous system; afferent. 

  • Of, relating to, or operated by centripetal force. 

perceptible

adj
  • Able to be perceived, sensed, or discerned. 

noun
  • Anything that can be perceived. 

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