73850
Descartes discovered an early form of the law of conservation of momentum ( a measure of the motion of an object ) , and envisioned it as pertaining to motion in a straight line , as opposed to perfect circular motion , as Galileo had envisioned it .
 person: Descartes; person: Galileo
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: Descartes, Galileo 
Answer:
 person: Descartes; person: Galileo