Time travel is a scientific fantasy activity, which means that people leave the present and stay in the future or the past. Time travel is one of the most exciting ideas in science fiction. When boarding the time machine, a person can use the control system to determine any date (past or future), and then the time machine can instantly take him to that era. Scientists believe that even if this becomes a reality, people can only be tourists and cannot change history. In a time machine, a person's age will be the same as when he entered the machine. Scientists believe that time travel cannot become a reality. After all, we haven't seen visitors from the future on the time machine.

Under the existing scientific system, time is strictly one-way. Of all the physical laws, only the second law of thermodynamics has an arrow pointing to time, giving people the feeling that time is flowing and disappearing. Therefore, whether looking back on the past or looking forward to the future has become an eternal dream of mankind.