Sounds like Futurama to me. I bet the world would probably be like Futurama by like 2250, if we discover how to travel in relativistic dimensons and speeds. Then again, if we ever did get FTL, would it change the world that much?
Technically, if time travel has changed our past, it has already happened.
In other words, if someone in 2500 decided to go to the roman empire and change something, those changes would have already been manifested in the history of the roman empire we know today. It's not like someone changes something, then the entire world history is changed, those changes have already happened in the past
Think about it.