11488
Despite the importance of this thought experiment in the history of quantum mechanics ( for example , see the discussion on Einstein 's version of this experiment ) , technically feasible realizations of this experiment were not proposed until the 1970 s .
 person: Einstein
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: Einstein