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Because it demonstrates the fundamental limitation of the ability of the observer to predict experimental results , Richard Feynman called it " a phenomenon which is impossible [ … ] to explain in any classical way , and which has in it the heart of quantum mechanics .
 person: Richard Feynman
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 person: Richard Feynman