Even if we could go back 120 years, just knowing it's possible to create aircraft doesn't do much without the domain knowledge to build one. FTL may or may not

Even if we could go back 120 years, just knowing it's possible to create aircraft doesn't do much without the domain knowledge to build one. FTL may or may not be possible via physics we don't understand. Until we have that physics and a system to exploit it FTL is a very real constraint to work around. Don't mistake "Nothing we can do" for "nothing we can ever do".