When you were a child, did you discover anything that made you curious? 그리고 어른이 설명을 해주었을 때, 그 대답을 듣고 새로운 질문에 대한 답을 더 찾아보게 된 적이 있나요? This is what happened to Carl Sagan when, as a child, he wondered what the stars were.