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Adaptive optics was first envisioned by Horace W. Babcock in 1953 , and was also considered in science fiction , as in Poul Anderson 's novel " Tau Zero " ( 1970 ) , but it did not come into common usage until advances in computer technology during the 1990 s made the technique practical .
 person: Horace W. Babcock; person: Poul Anderson; media: Tau Zero
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
 Entities: Horace W. Babcock, Poul Anderson, Tau Zero 
Answer:
 person: Horace W. Babcock; person: Poul Anderson; media: Tau Zero