If you left Interstellar confused and without understanding of what happened near the end, you may of wanted director Christopher Nolan’s brother (who co-wrote the script) to handle the ending rather than The Dark Knight director (which ended up being the ending used).
Warning: Spoilers Ahead
At the end of the film, we see Matthew McConaughey’s character jettison himself into the singularity of the black hole Gargantua. He makes the deadly journey in the hopes of characterizing gravity acting at the smallest scales inside, and to send that data back to Earth. He survives the descent, but then finds himself inside a 5th-dimensional “tesseract,” which he uses to peruse the timeline of his life and contact his daughter’s younger self.
According to Jonathan Nolan while speaking with the Nerdist on Thursday, his originally planned ending was more steeped in science and would’ve been more straightforward.
Nolan said that his original ending “had the Einstien-Rosen bridge [colloquially, a wormhole] collapse when Cooper tries to send the data back.” This meant no tesseract (Christopher’s idea), no time manipulation, and no return home. It would’ve meant a more bleak and darker ending than the one that Christopher added to the film.
According to the site, if the wormhole collapses, that means there is no way for Cooper to get home (though the data maybe made it back to help the dying Earth), no way to find Anne Hathaway’s character, and likely a one-way trip into a black hole.
While the ending that was put into the film was more ambiguous, it seemed like Jonathan had a different direction to the film that would’ve made much more sense to some of the critics of Interstellar.