[withinboredom]

A rocket engine (in its entirety) is probably not something you'd patent, probably because of precisely this issue. A sensor that can detect light is also likely not patentable, even if how it does so is novel. That seems ridiculous to me; there needs to be a point at which a patent, no matter how novel, shouldn't be possible.

Maybe I'm wrong, but I'd love to be on that jury.