8 Iconic Doctor Who Things That Scientists Say Are Real

4. Bigger On The Inside

Speaking of TARDISes, lets talk about its most striking feature - its bigger-on-the-insidedness. It is heavily implied in the show that the interior of the TARDIS exists in a different dimension to the exterior, which would not only offer an explanation for how it can be bigger on the inside, but also tie in with the whole time travel thang. If the interior of the TARDIS actually exists in four-dimensional space, we'll call it the Time Vortex, then the exterior would be a three-dimensional projection of this four-dimensional object at different points in space and time. It represents the "true" TARDIS in the same way a muddy footprint represents a boot. In order to access the fourth dimension, you have to be able to travel at 90 degrees to our three-dimensional reality - that is, in a direction other than up, down, left, right, forwards and backward. Alternatively, you could always flag down The Doctor and simply walk through the blue doors. Another possibility hinted at in the show is that the TARDIS has some kind of artificial compression field on it. This would presumably remove some of the empty space out of all the atoms that make up the interior and squeezing it, and the people who inhabit it, into the little blue box. Squeezing lots of matter into a small space, however, massively ramps up the density which, in turn, causes spacetime to bend much more dramatically around it. In fact, considering the heavy hints that the TARDIS interior is actually infinite, this is how you end up with black hole-like objects. Incidentally, the TARDIS is supposedly powered by a black hole, so perhaps we're on to something?