The Doctor Who Theory That Connects It To The Hitchhiker's Guide To The Galaxy
Fans of "Doctor Who" have been conjuring up their own theories, backstories, and fan fiction related to the show's titular star for over six decades now, many of which connect the iconic BBC series to other famous works and characters, like James Bond. Another one of the show's other long-rumored links is actually one that a lot of people may not know about, involving Douglas Adams' 1979 novel "The Hitchhiker's Guide to the Galaxy" and one of its most pivotal moments. Shown in both the book and 2005 film, the scene involves what is a seemingly strong connection to Adams' subject material.
Once serving as a script editor for "Doctor Who," Adams made sure to reference a number of different characters and items from the legendary series in "Hitchhiker's Guide," as did future writers of "Doctor Who" with his book. For example, the Altairian dollar is a form of currency in both mediums (via Tardis Fandom). Vogons, an alien species from "The Hitchhiker's Guide," are also mentioned in Doctor Who stories. But it's the theorized connection we discuss below that is perhaps the biggest and most noticeable.
The Doctor's Name Is '42,' as is the answer to life in Hitchhiker's Guide to the Galaxy
As seen on Reddit, fans believe that "Doctor Who" and "Hitchhiker's Guide" are both directly connected and existing in the same universe on account of them each sharing a search for life's "ultimate" and "oldest" question.
In "Doctor Who," the Oldest Question in the Universe is posed during the show's sixth season starring David Tennant. While it must never be uttered or talked about, viewers eventually learn that the question is simply "Doctor Who?" (via Tardis Fandom). In "Hitchhiker's Guide," the answer to the Ultimate Question of Life turns out to be the number 42, but we never actually find out what the question is.
While it may seem like a stretch, fans believe that BBC's famous Doctor could in fact be known as "42" to his fellow Time Lords on Gallifrey, who had initially sent out the "Doctor Who?" message from Season 6 which turned out to be the Oldest Question. In the show, the Time Lords had been searching for Tennant's titular hero while trapped in a pocket universe. They sent out their message as a way to prove it was safe for them to reappear through the Doctor uttering his true name.