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Not sure what to make of this image, which gets the title “She is coming.” It turned up on twitter via #DoctorWho. Has anyone else come across it?
Mark Gatiss is, surely, showing-off a Lethbridge-Stewart moustache.
@nerys Insignificance Terrific movie! As well as the explanation of relativity, it also carries a very powerful punch and moral message at the end. Here’s Marilyn (played brilliantly by Theresa Russell) explaining special relativity to Albert:
@mudlark @thane15 @nick @ichabod As I understand it (but my physics is now rusty), given the size of the time-dilation effects that are in play, the tidal forces acting on the ship and the inhabitants would have ripped the inhabitants apart provided the black hole does not contain too much mass. That is, the difference between the gravitational force acting on someone’s head compared to the force acting on their feet would have led to what’s been called above spagettification. But if the black hole contains enough mass, then someone could make it alive into the event horizon. See the stuff pasted in below for more information (courtesy the University of California, Riverside). The key sentence is perhaps this one: “So for black holes larger than about 1000 solar masses I could probably fall in alive, and for still larger ones I might not even notice the tidal forces until I’m through the horizon and doomed.” So if the engines on the ship fail, or if they are turned off (by a very wicked Time Lord??), the ship could enter the event horizon, and then all bets are off, and to get out the Doctor will really have to do something extra-special that we’d all applaud.
The 1979 movie The Black Hole begins with the U.S.S. Palamino chancing upon a spaceship so near to a black hole that it should have been ripped apart and destroyed long before. So the starting point for the movie is, how has the spaceship defied the laws of physics?
On time being reversed, as @tardigrade pointed out above and I believe this is right, the direction of the time flow does not change between the top and bottom of the ship. But it seems to me there’s ‘Doctor Who Physics’ and ‘Real Physics.’ So in Doctor Who Physics we get time dilation and no tidal forces (but perhaps the black hole the ship is trying to pull away from has a mass rather greater than 1,000 solar masses!), and, quite possibly, in Doctor Who Physics, we’re about to get time reversal in a very powerful gravitational field. But to this point, as I read it, the set-up in terms of general relativity has been o.k. in principle provided the black hole is massive enough. Its also Moffat and so surely all the really weird time-wimey stuff ain’t over!
Here’s some directly relevant stuff from a site I’ve found useful before (from the University of California, Riverside): http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/fall_in.html
Suppose that, possessing a proper spacecraft and a self-destructive urge, I decide to go black-hole jumping and head for an uncharged, nonrotating (“Schwarzschild”) black hole. In this and other kinds of hole, I won’t, before I fall in, be able to see anything within the event horizon. But there’s nothing locally special about the event horizon; when I get there it won’t seem like a particularly unusual place, except that I will see strange optical distortions of the sky around me from all the bending of light that goes on. But as soon as I fall through, I’m doomed. No bungee will help me, since bungees can’t keep Sunday from turning into Monday. I have to hit the singularity eventually, and before I get there there will be enormous tidal forces—forces due to the curvature of spacetime—which will squash me and my spaceship in some directions and stretch them in another until I look like a piece of spaghetti. At the singularity all of present physics is mute as to what will happen, but I won’t care. I’ll be dead.
For ordinary black holes of a few solar masses, there are actually large tidal forces well outside the event horizon, so I probably wouldn’t even make it into the hole alive and unstretched. For a black hole of 8 solar masses, for instance, the value of r at which tides become fatal is about 400 km, and the Schwarzschild radius is just 24 km. But tidal stresses are proportional to M/r cubed. Therefore the fatal r goes as the cube root of the mass, whereas the Schwarzschild radius of the black hole is proportional to the mass. So for black holes larger than about 1000 solar masses I could probably fall in alive, and for still larger ones I might not even notice the tidal forces until I’m through the horizon and doomed.
A fun romp with some serious themes also in play. Hammer horror meets Zulu. And a good change of pace from the Monks (sort of) Trilogy. If we’d not known the writer, I think we’d have all picked Mark Gatiss.
Greatly enjoyed what I take was a visual reference to Tomb of the Cyberman.
Bill’s right. Everybody loves The Thing.
I’m with @scaryb, @missrori and @winston on Missy. It’s surely a question of time and not if she reverts to type.
A great pity the Queen Victoria portrait showed Pauline Collins; a portrait of Clara as Queen Victoria would have have been a wonderful stimulus to bonkerising….
@missy By this point, my own money too is firmly on an alien race running alone, but have a lingering hope for a connection! The red habits of the Monks are a bit suggestive with red being such a Time Lord colour. For fun, I took the Doctor’s advice, went to Google Images and spent ten minutes entering various search terms such as `Doctor Who and Evil Time Lords.’ Taking @missrori‘s advice and ignoring the Rani and the Valeyard (and ignoring other surely too obscure ones like Morbius), got to Omega, who I’d forgotten needed two Time Lords to defeat him. Get Missy out of the Vault! Also, the Peter Pratt and Anthony Beevor version of the Master in The Deadly Assassin & Keeper of Traken appear, if you squint, a little Monk like, though he has clearly been to a better dentist than the Monks.
