“The big one, though, is that representation matters: a female Doctor will tell little girls they can play the lead, just as Wonder Woman told them they could be a superhero. There’s a video going round Twitter at the moment of a girl, perhaps nine years old, watching the BBC as the casting is revealed, completely silent until the very end. Only then does she turn to the camera with the biggest grin you’ve ever seen and scream, “The new Doctor’s a girl!” That is why this is a great day, right there.”