A biologist signs up for a dangerous, secret expedition into a mysterious zone where the laws of nature don't apply.
Movies in the vein of 'Limitless': contemporary mystery films made especially labyrinthine by the introduction of space-age tech, extraterrestrial interlopers, and time travel.
Movies in the vein of Interstellar: These cerebral sci-fi masterpieces are guaranteed to get you thinking about time, space, destiny, free-will, and pretty much every other insoluble existential mystery. The thinking man's blockbusters!
Webster's English Dictionary defines hard science fiction as being 'characterized by an emphasis on scientific accuracy or technical detail or both' (just kidding it's Wikipedia). So, basically sci-fi that would satisfy 'Comic Book Guy' from The Simpsons.