Not all of the science needs to be fictional... presumably gravity will comtinue operating as it does today, tomorrow. Black holes will operate the same as well

Not all of the science needs to be fictional... presumably gravity will comtinue operating as it does today, tomorrow. Black holes will operate the same as well, unless the story gives it reason not to (black hole combobulators). The "fiction" is only necessary for the stuff that doesn't exist today.