Since we're on it, there's actually a book about the science of interstellar.

https://www.amazon.com/Science-Interstellar-Kip-Thorne/dp/03...

Side note - there's a really neat write-up by someone who realistically rendered a rotating black hole in 1979, partly by computer and partly by hand [0]. He goes through all the important visual effects, like GR ray tracing, disk brightness, and Doppler shift. The final image is pretty cool.

[0] - https://blogs.futura-sciences.com/e-luminet/2015/02/18/black...

If I recall this correctly, the movie intentionally simplified the rendering of the black hole (by eliminating the Doppler shift) to make it more visually appealing.

Pity, really. Then again, there were other things that made no sense in the movie...