According to the definition of time travel, the travelers journey as judged by the travelers clock takes a different amount of time than the journey does as judged by the clocks of those who do not take the journey.
Theres a way now for you to visit Sacramento in 2188 (In case of a zombie attack be sure to take this kit with you).
How long does it take to fall into a black hole?
Paradox of Free Information In 2077, time machines are invented. In 2099 Jones discovers a drug that cures cancer. Jones patents her drug in 2100. In 2121 Smith makes a copy of the patent, enters a time machine, and goes back and gives the copy to Jones in 2099 who then uses it to create a drug that cures cancer. Who had the idea first?