What science fiction writer was a radar instructor during World War II?

Arthur C. Clarke was a radar instructor during World War II. After the war, he actually got a degree in mathematics, not English or a related field that one would think of when thinking of an author’s degree. Most of his fame comes from being a co-author for the script of the famous movie “2001: A Space Odyssey”. However, for many years afterwards, he was considered to be one of the big three of science fiction, right up there with Isaac Asimov and Robert Heinlein.

Despite being born in England, Clarke relocated to Sri Lanka in 1956. The main reason was his interest in scuba diving, but there are rumors that he moved to Sri Lanka because of relaxed laws regarding homosexuality, comparative to the rest of the world at the time.