Interstellar Is a Terrible Movie. Matthew McConaughey is terrible.

Famous physicist Kip Thorne is a producer on Interstellar, and worked to ensure that nothing in the film disobeys accepted laws of science, and among other things that the black hole visuals were based on sciencey equations. That's great, but there were not nearly enough awe-inspiring scenes of science to save the film.

Kip Thorne probably knows more about relativity than I know about anything. In his book The Science of Interstellar, he writes

I suggested [...] two guidelines for the science of Interstellar:
1. Nothing in the film will violate firmly established laws of physics, or our firmly established knowledge of the universe.
2. Speculations (often wild) about ill-understood physical laws and the universe will spring from real science, from ideas that at least some “respectable” scientists regard as possible.

However, there is a great divide between what can be predicted by physical laws, and what silly speculations technically avoid disobeying them. Interstellar does nothing to separate what is science from what is fantasy that might not yet be known to be impossible. I don't think Interstellar could be called a science movie. It's not even nearly plausible science fiction. At best it is science fantasy that is speculatively not proven to be completely impossible according to "some 'respectable' scientists".

SPOILER WARNING...

That's what made the film not great. Here are some of the things that made it bad:

• The whole "average farmer/world's greatest pilot gets to fly the space shuttle and save the planet" trope. Why go from "even his kids' teachers don't respect him" to "he's flying manoeuvres that none of the scientists or flight computers knew were possible," over the length of the film? Why does there have to be a single space cowboy superhero who outdoes everyone else in existence and is constantly impressing everyone (and us!) by doing the implausible? In a real scientific movie, such as Apollo 13, great feats were pulled off by teams of cowboys and engineers, with no super-human individuals, but achieving superhuman greatness by all working together as a sum of parts. Why do we need the unlikely "every human is useless except the chosen one" crap?
• Matthew McConaughey. Props to the filmmakers for hiring someone with such a disabling speech impediment, but anyone else would have been a better choice.
• Square robots. Someone really liked the shape of the 2001 A Space Odyssey monoliths, but for robots and TV panel display cases they are entirely inconvenient. The robots are awkward and ungainly. Worse, where they could have showed off how a well-designed robot might adapt to handle different situations, the filmmakers instead get to show off how a poorly designed robot might be (implausibly!) forced to do so, and in doing so become a superhero too, eg. conveniently forming a self-propelled paddle wheel out of its inconvenient big-metal-box components.
• "Dudes, let's surf this gravitational wave!" The science of black holes and junk is fascinating on its own. It doesn't have to be turned into an adventure sport to hold our interest.

Overall I give it a 4/10 thumbs up and would recommend watching it for the visuals and the rare moments of interesting science. If you are not able to easily switch your brain off for the rest of the film to enjoy it despite the dumbness, then I'd avoid this film because it might cause brain damage.