Doctor Who director reveals the mathematical equations that helped make a fan-favourite episode

Rachel Talalay has unearthed a document that shows the thought that goes into Doctor Who’s various stunts


If you’re the sort of person who argues about the representation of parsecs in Star Wars, the relative raven speed in the latest Game of Thrones episodes and the multiple time paradoxes of Harry Potter and the Cursed Child, you’ll be pleased to know that there’s one beloved fan franchise that doesn’t skimp on the science – Doctor Who.


You see, while we’ve long known that Doctor Who is a series that takes science (relatively) seriously – that time dilation storyline in the last series totally checks out, for instance – a new piece of evidence has emerged to show that detailed calculation goes into the most fantastical of setpieces.

See that effort? Regular series director Racehl Talalay tweeted this document from the production of fan-favourite episode Heaven Sent (where Peter Capaldi’s Doctor is trapped in a puzzle prison with a monster), showing that a scene where the Doctor dives from a high window into a lake (or moat) had a LOT of thought put into it.

Drawing from physics and real-life examples of skydivers, the note estimates that it would take the Time Lord just 3 seconds to reach 50% of his terminal velocity (about 61mph out of 122), with 15 seconds passing before he reached the full speed and the end results presumably being factored into the finished scene.

It’s a rare insight into just how much mental exertion goes into working out the nuts and bolts of a show as complicated as Doctor Who – and given how well-received Heaven Sent turned out to be, we’d say it was well worth it.


Doctor Who returns to BBC1 this Christmas