If in the future people are able to time travel...?

[EnglishGirl]

then why hasn't anyone seen a person from the future in the past? or...
If time travel is going to be possible would the people be 'invisible' to us?

I appreciate that this question has no proof yet, but what have you heard from scientists?
Thanks

 

[charleneq86]

nobody will ever be able to travel in time, its just a fantasy.