#... First. Theoretically, humans can never reach the speed of light, only infinitely close. Second, by normal logic.... Earth would have lived many, many years, although the man had only lived one year. But there is a paradox here, I don't know if you've heard of the twin paradox, I won't go into the details, it's the same situation as your question, if you take the earth as a reference, then there will be a time difference as mentioned before, but if you take the spacecraft as a reference, the situation will be the opposite...
There is a paradox here, I don't know if you've ever heard of the twin paradox, I won't go into the details.