Long Riddles and Answers

Question: Occurring once in a hundred years and once in thousands. But never in a day or a year or a century.

Question: A ship was travelling in a sea. What is the name of the captain? The answer is in the question.

Question: I am life without death, death without life, a world with no space, space with no world What am I?

Question: I start at the beginning and I finish at the end I fly through the middle and I return again.

Question: I don't have eyes, but once I did see. Once I had thoughts, but now I'm white and empty. What am i?