Neil deGrasse Tyson has already assessed the science in "Interstellar," but since you're probably still confused about the movie's ending, here he is explaining things like time, space and how Coop (Matthew McConaughey) was able to enter the fifth dimension (you know, that library tesseract thing) to contact his daughter in the past. Most of Tyson's chatter is about the overall mechanics of these concepts and how they relate to black holes, but it's fairly simple to apply his explanations to Christopher Nolan's complicated conclusion. He does emphasize that it's all speculative because we don't know what's in a black hole or whether past events are actually amendable in higher dimensions. Still, maybe the Business Insider video will help you wrap your head around the movie's puzzle. If not, he pretty much says, "Oh, whatever!" at the end -- and what Neil deGrasse Tyson says goes.