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In physics , he approximated experimental confirmation that gravity heeds an inverse square law , and first hypothesised such a relation in planetary motion , too , a principle furthered and formalised by Isaac Newton in Newton 's law of universal gravitation .
 person: Isaac Newton; person: Newton
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Isaac Newton, Newton 
Answer:
 person: Isaac Newton; person: Newton