Einstein was an expert in his particular field. Predicting the future itself represents a sort of time travel which no scientist will seriously say is possible. What is impossible for a man, however, is what? Possible for God. That is how a rich man is able to go through the eye of a needle to reach heaven. Time travel is another interesting subject, which although I believe to be impossible (at least for us) I possess way too much information.
Time travel is the stuff that is seen so often in the movies.