I am not a good man! I'm not a bad man. I'm not a hero. I'm definitely not a president, and no, I'm not an officer. You know who I am? I… am… an idiot! With a box and a screwdriver.
Why it is hard sci-fi
Soft. Doctor Who is on this list as a cultural anchor and as the longest-running science fiction series on television. The shows physics is opportunistic. What it commits to is a consistent grammar of fixed points in time, the laws of time that the Doctors people enforce, and a non-violent epistemology in which problems are usually solved by understanding rather than firepower.
Science inside it
Time travel as a working device with self-imposed rules, regeneration as a physiological cycle that resets a Time Lords body, dimensional transcendentalism in the TARDIS, and a sonic screwdriver that is admitted in-show to be a plot device. The shows rule about fixed points is the closest it has to a hard physics constraint and is followed.