We explain how the iconic and enigmatic TARDIS of Doctor Who really works.
While Star Trek and Star Wars are the new hotness now, a major Doctor Who revival is just around the corner. In addition to getting a brand new Doctor, we’re also getting a few more episodes with fan-favorite David Tennant doing his timey-wimey thing. And now that the BBC is working so closely with Disney to bring this series to America, we decided to tackle the big question: just how does the TARDIS work in Doctor Who?
On the show, the basic idea behind the TARDIS is simple. The name itself is an acronym for Time And Relative Dimension In Space. In short, rather than having to get someone like Mr. Spock to time travel by slingshotting around the sun, the Doctor can simply travel to any point in space and time that he (or she) chooses.
But how does this actually work? Ages ago, the powerful Time Lords created countless wormholes throughout the known universe. These wormholes are collectively known as the time vortex, and when the Doctor travels through time and space, the character is actually taking the TARDIS through this vortex.
However, when you stop to consider the sheer physics of how everything works with the TARDIS, it gets really complex, really quickly. For example, the tiny blue box that we see is not really the TARDIS itself. This is tied to why “it’s bigger on the inside” (more on this soon), but right now, it’s most important to know that the tiny box we see is really just a shell disguising a much larger vessel.
At any given point, the TARDIS effectively occupies two different points. The first point is an area in space-time that allows our characters to occupy the vessel and eventually travel to another destination. But at the same time, the TARDIS is also occupying another point in the vortex, and when the Doctor takes that big blue box somewhere else, it is effectively moving from one point in space-time to another using the aforementioned time vortex.
Here’s one thing about the TARDIS that might freak out longtime viewers: despite all those times we’ve seen the TARDIS fly, it’s not actually flying or even moving during most trips through space-time the way Harrison Ford flies the Millennium Falcon in Star Wars. Remember when we mentioned that the vessel is connected to the time vortex at all times? Once the Doctor gets the coordinates punched in, the TARDIS simply accesses the time vortex and shifts from one location to the next.
What’s going on, then, when we do see the TARDIS flying? When the vessel is doing things like flying alongside a car in the episode “Runaway Bride,” the Doctor is essentially forcing the TARDIS to change its space-time position on the fly, allowing it to physically move rather than simply shift from one place to another. Of course, the Doctor sometimes has difficulty getting the TARDIS to do as it’s told for an unexpected reason: the vessel is actually alive.
The Time Lords never build a TARDIS; rather, they grow them, and the fact that these vessels are both living organisms and highly intelligent helps them to navigate the time vortex. In the episode “The Doctor’s Wife,” the Matrix of the TARDIS is put into a woman, allowing the Doctor to speak to his vessel for the first time.
There, she revealed two unexpected facts: that it was she who chose the Doctor and not the other way around, and that she often used her knowledge of space-time to always take the Doctor where he needed to go (even if it wasn’t where he wanted to go).
All of that brings us to the question of how and why the TARDIS is famously “bigger on the inside,” and the short answer is that the interior of the vessel occupies its own separate dimension. It’s a 4D shape that is more complex in design even than a tesseract, and as characters move through it, their brains perceive everything as so big because the mind can’t really comprehend walking through time like this.
Kind of like if you were to become unstuck in time and could move backward and forward in it, things would likely look very different from our boring and linear reality.
As a franchise, Doctor Who has been around longer than Star Trek and Star Wars, and both the creators of the show and fans have had a long time to work out exactly how the fantastic TARDIS is supposed to work. But the show is still full of many contradictions (if you want to start a fight at the Doctor Who convention, go ahead and ask if the Doctor is half-human) and never takes itself too seriously. So if you want to throw out all the science and just enjoy the adventures of a madman with a box, we won’t hold it against you.