It's always the same with me and Professor Brian Cox – fine to start off with, less fine later. Here in The Science of Doctor Who (BBC2) he takes a spin in the actual Tardis with Matt Smith – a little dramatic introduction, to warm us up to the idea that nothing is impossible. "Space and time, time and space, locked in an intricate dance across the cosmos, and if you know the tune anything is possible," says the Doctor. Never mind the science, that's lovely; drama's easy, no problems for me here.
Then it's into the lecture hall of the Royal Institution for Prof Cox to explain whether and how it's all possible. The place is full of stars and television personalities; it's like its own mini solar system of celebrity. Brian is the sun of course, the centre of it all, around which the others circle, drawn by the pull of his mind, the light of his smile, and the Bliss of Knowledge. They applaud each other, just for being who they are ... Oh shut up! I'm just jealous, that I'm not invited. I'm just part of the black void beyond. Well, there certainly is life out here – pond life maybe, but life all the same.
Anyway, time travel: is it possible? Brian would go back to this exact place, the Royal Institute in 1860, to a lecture on the chemical history of the candle given by Michael Faraday, who was pretty much the Brian Cox of his day (though perhaps not quite so much as the charismatic Humphry Davy was, a little earlier). Then we're off, into time and longitude (got it, easy); electricity and magneticism (mmm … getting trickier, unless we're talking about Prof Cox himself, who's got an infinite amount of both); Maxwell's wave equations and relativity (forgetaboutit).
Actors, presenters, comedians [applause please] join Brian on stage to make bangs, do jokes about hair and masturbation, wear strap-on clocks, and ride skateboards with light clocks in the dark. So if Jim Al-Khalili here goes off on his skateboard at very nearly the speed of light, then returns in, say, 10 years by his watch, he'll find that more than 10 years has passed. The speed of light is constant, but time is personal, and Jim will have travelled to the future. I still more or less get it! Time travel is not just possible, it's an intrinsic part of how the universe works.
Yeah, but that doesn't take the Doctor back to anywhere or anywhen in the past, does it, or Brian back to his famous candle lecture. It gets more complicated going backwards. He's talking about "singularities", "event horizons", "future light cones" and a "sort of immortality". Suddenly I'm at that point I always get to with Brian, my own grey matter becomes a black hole. I reach my own personal event horizon, and topple over.
Perhaps that's the problem – that I'm trying to visualise everything. Like my future light cone, which is supposed to encompass not just my future, but all our futures. All I'm seeing, though, is one of those lampshades dogs have to wear when they're sick. I'm trying to bend it round (through space-time, I think) into the past but I can't, just as the dog can't in order to lick its wounds. The cone-shape is the problem. What happened? I was supposed to be a Time Lord; instead I'm a mangey labrador. Even as K-9, it's not working. I can't get back there.
It doesn't really matter. I did OK. And anyway, that's about right. It's very very hard to bend a light cone and reattach spec-time into the past. Probably impossible, though no one has proved it.
There you have it then. Doctor Who is part-science fiction, part-science fact. Forward time travel: possible, but you need a very quick skateboard. Backward time travel: too tricky. Oh and aliens? Certainly possible, but not found yet. Apart from the Weeping Angels, which are in your attic, and are just waking up right now … (Cue Doctor Who music.)
The timing for North Korea: Life Inside the Secret State (Channel 4) was grimly apposite, in a week when a South Korean paper claimed that 80 people had just been executed over the border for, among other things, watching foreign TV. Here we see a defector sneaking movies – Skyfall among them – back into a country hungry for knowledge of the outside world (as well as just hungry). Along with smuggled-out footage filmed by a network of undercover agents inside the country.
This Dispatches film is a better one than John "007" Sweeney's recent Panorama, because it doesn't have that look-at-me-fearless-journo-on-ego-minibreak element. More North Korea for – and filmed by – North Koreans then, not North Korea for John Sweeney. Which you could say is more important.
