The Science of Doctor Who: s01e09-10, “The Empty Child / The Doctor Dances”
Nanobots, nanites, nanogenes: these are all science-fiction terms for microscopic robots that can repair or create materials one molecule (or atom) at a time. We dream of building super-strong metals from base elements, or sending them into our bodies to remover cancers or repair damage. We’ve already made a few very crude examples, ver basic mechanisms only a few molecules in size!
But some science-fiction writers use this as a synonym for “magic” when they’re in a hurry; though this is an excellent Who story – one of my favorite tales of the Ninth Doctor – Moffat succumbed to the temptation. In seconds, these tiny little robots scan an unknown life form, determine how it is put together, determine damage, and repair it. It’s hard to imagine how they’re doing this. We can see no visible power source or external computer support, and a nanobot has to be a *very* simple device, by basic laws of physics. For example, a real cancer-killer nanite wouldn’t be complicated enough to do much more than blindly swim through the body until it bumped into something it could recognize as cancer.
If we grant that the nanogenes are smart enough to scan a body and do major conversion work with no power or raw materials other than the body at hand, we get other problems. How were they dumb enough to think the little boy’s gas mask was his body, but not his clothing? (Would have been great to see everyone with the nanogene infection forced into short trousers.) Also, the little bots are dumb about the gas mask but smart enough to recognize different genders, heights, weights, hair colors; that’s some odd programming. Must still be in beta.
Somehow they work, though. And the Doctor literally hand waves the job of reprogramming them to repair everyone properly. Now we bump into a common sci-fi peeve of mine: where did the reprogrammed nanogenes get the information to put everyone back together again properly (again with all the different genders, heights, weights, and hair colors)? If the answer is, “they extrapolated everyone’s DNA”, well that’s great. If they could do that, the nanogenes probably should have been doing that when they scanned the little boy in the first place? I’d also love to know how the critters were able to destroy everyone’s minds, but completely restore them afterward. It would be like smashing your hard drive, buying a new one, and expecting all your data to be on it. Doctor Crusher liked to ignore this problem on the Enterprise-D, too.
One last nit to pick: I’ve lived through my body trying to rebuild just a couple of smashed bones. The physiological stress of the conversion to gas-mask zombie in the first place would kill you. Between the excrutiating pain, and the sudden changes to your biology, your body wouldn’t handle the shock. The conversion process would make more sense if everyone’s body went into a coma for weeks before emerging as a gas-masked little boy, but I’ll concede that would be lousy TV.
Next time: I’m afraid I’ll have to blow up the Earth. It obstructs my view of Raxacoricofallapatorious.
The Science of Doctor Who: s01e08, “Father’s Day”
The Doctor takes Rose Tyler back to the day when her father died, an event she was too young to witness and understand. In an impulse, Rose interferes with the death, and Time starts to unravel with fatal consequences to everyone nearby.
There aren’t many scientific concepts explored or mentioned in this episode, though Alexander Graham Bell is misquoted when cell phones start repeating “Watson, come here, I need you.” The proper quote is supposedly, “Watson, come here, I want you.” But on the other hand, Time’s damaged, so maybe it’s an alternate Bell speaking? As nitpicks go, that’s easily addressed.
I’m more interested in the way this episode treads in dangerous waters by discussing the way time travelers may interact with the world in their past and future. It’s a question that rarely bears serious examination, because things quickly don’t make sense. The show has contradicted itself many times over the decades, and will continue to do so as the seasons progress.
The Doctor tells Rose they can’t change something they’ve witnessed themselves, which fits the general tone of the show and prevents tension-killing easy answers to the many plot problems the characters have faced. But just what can we say is “witnessing”? Is a transmission over closed-circuit TV something one may change, but physical line-of-sight is not? What’s the range? If Rose looks at a star 1,000 light years away in the night sky, then visits a planet around that star 1,001 years ago, can she be certain that the supervillain won’t be able to blow the star up because she saw it perfectly healthy a “year” later?
Once again, you can figure out that there’s no way to answer these questions fairly and rationally because it makes the TV show impossible. And we don’t want that, so in the immortal words of the MST3K theme, “Just repeat to yourself, ‘It’s just a show, I should really just relax.'” But that doesn’t mean we aren’t allowed to think about the problem. We can set it aside for the duration of an episode, but entertainment doesn’t have to reflect reality perfectly. And I feel perfectly comfortable gently poking my favorite universes this way – it’s done with love, and I’m hardly going to stop watching.
The Science of Doctor Who: s01e07, “The Long Game”
It’s the year 200,000, and the Doctor, Rose, and Adam arrive on an Earth-orbiting space platform that has somehow become inhabited completely by the mid-21st century. Well, that’s not quite the plot, but it’s a sin that current sci-fi TV keeps committing over and over. Fashion, food, and entertainment are all exactly as we might expect them to be a decade or two from now, and while the plotline suggests that Earth’s cultural development’s been held back, this is a bit much.
Can’t I have just a little space fashion, space food, and holographic display tablets? I know it may come off as a bit silly, but silly beats lazy any day on Doctor Who. (Okay, “kronkburgers” are mentioned, and are an in-joke from old Doctor Who comic strips. So maybe the food is a *bit* futuristic, but the burger stand hasn’t changed in 198,000 years.)
Moving on past that, some people on Satellite 5 have dataports for high-speed super-broadband wireless data streaming directly into their brains. Sure, that’s very cyberpunk and an integral plot point; I don’t have any problem with that. However, to add “ew, ick!” factor for the eight-year-olds, they made the dataports into little doors that open up directly to the surface of the brain. Immediately, I started thinking “Well, there’s a fatal infection just aching to happen.” And why bother, given that there appears to be no hardware installed in the brain itself? You should be able to find an electromagnetic frequency that would pass through skin and bone well enough. While the transmission shows a visible beam, that would have to be a side effect: if the information is carried on visible light pulses, the brain tissue itself would block them. Brains aren’t transparent.
Now we head up to Floor 500, where we discover that the satellite is owned by a giant slug shark, managed by New Scotty, and operated by frozen zombies. Oh, dear, zombies again. Let me quote myself from “The Unquiet Dead”: “centuries of embalming technology has blinded modern humans to one fact: dead bodies decay. Shortly after death, various chemical processes in a body are no longer inhibited or controlled; it doesn’t take long at all before eyes are useless for seeing, internal organs are useless for digesting food, brain tissue cannot carry electrical charges, and muscles will no longer flex and pull.” And let me tell you that freezing the dead tissue doesn’t make it any better at doing any of these things.
Frost-encrusted dead people should have been about as useful to the operations of Satellite 5 as a frozen pack of convenience-store beef jerky, and about the same consistency, but as a culture we just can’t seem to get rid of our zombies, can we? Wouldn’t it have made just as much sense, and in fact be a delicious irony, for the Satellite operators to be alive and mind-controlled though the very dataports they were so eager to have installed?
Oh, and Adam is kind of a weasel, isn’t he? Of course, he was written that way in “Dalek”, so fair enough.
Next: an episode that will have repeated repercussions for Rose Tyler.
The Science of Doctor Who: s01e06, “Dalek”
Remember these? It’s only been a gap of nearly three years, after all, hardly a blink in the overall scheme of space and time and universes. And while my focus will remain on the science issues of the scripts, there’s likely to be commentary on plot elements too. There’s simply too much to talk about as new Who evolves. So lets talk about one of the best episodes of the Ninth Doctor, and probably the best Dalek episode since 1963.
The Dalek itself doesn’t pose too many science problems. It’s a mobile armored life-support unit for the Kaled mutant inside, and while some of the construction materials and power sources might be a little implausible, there’s nothing especially offensive there. However, I would like to know how the Dalek regenerates itself simply by “extrapolating the DNA of a time traveler”. I’m willing to accept that there’s a cloud of strange energy following time travelers around because of their exposure to the Time Vortex and the energies powering the TARDIS. I have more trouble that a simple touch from Rose could provide the Dalek’s nanomachines (of course it’s nanomachines, right?) with enough energy and raw materials to repair all the visible damage. Just how much time-zap do Rose and the Doctor carry around, anyway?
“The Dalek’s downloading the Internet!” Well, that’s great. But here’s how the Internet works: There are a bunch of files on a computer somewhere which make a game or a web page. Your computer sends a request from your home connection, to your Internet provider, to the big telecommunications networks, to the other computer’s provider, to its connection, and finally to that computer, which sends you the file(s) back over a similar path. Each part of that path can only send so much data so fast, so it doesn’t matter if your computer and your connection can download the Internet in an hour unless all the other parts of the path can.
And, well, even if super-rich guy has the special private uber-connection into the big telecoms, it doesn’t help. You still are limited by the capabilities of the local networks and computers from which you are downloading. So, sorry… no downloading the Internet in an hour, even if you are a Dalek. (And by the way, they’s why the “I own the Internet” line makes no sense whatsoever. Own all the big telecom companies? Well… maybe. Maybe. He sure as hell doesn’t own all the ISPs and the computers attached to them. Sorry, big guy.)
Oh, and could someone tell van Statten that we’ve invented all sorts of machines even in real 2005 that can scan someone’s biology without causing them excruciating pain? X-Rays, MRIs, tomography machines… van Statten’s clearly a bit of an idiot who doesn’t care how much he’s damaging the thing he’s “studying”. Hell, if he took proper care “studying” his specimens, he’d probably have learned so much that he really would own the planet.
And speaking of which, what sort of idiot kills people on a whim if they fail to amuse him? He’s a monster, and it’s played for a giggle but is really not funny. The guy’s lucky one of his own men hasn’t shot him in desperation by now if he’s been making a habit of this. And don’t tell me van Statten isn’t really having them killed: if your memory’s been wiped clean, your body may still be alive, but you are gone. You are never coming back. He’s a murderer on a whim, and I can’t say I’m sorry he gets the same done to him. (Yes, that means that Bail Organa and Owen Lars are also cold-blooded murderers, and no I’m not kidding.)
Still this is a great episode. Rarely has a Dalek been this terrifying; we can see that stairs really don’t bother them; and as someone said, this is the episode where a Time Lord acts like a Dalek, a Dalek acts like a human, and a human acts like a Time Lord. Some excellent acting all round, and this is one of my favorites. See you soon for “The Long Game”.
The Science of Doctor Who: s01e04-5, “Aliens of London / World War Three”
Okay, huge gap between the last SoDW and this one. This is mainly because I really didn’t like this episode at all. The villains’ main characteristics were that they farted and giggled constantly, and the plotline itself seemed silly and self-indulgent on the part of the writer. (Oh, had I only known.) But in no particular order, let’s look at some of the scientific and technical details of the two-parter.
UNIT’s website can order UK military submarines to launch missiles; and the password is “buffalo” – a seven-character word, one found in English computer spellcheck dictionaries. From an Internet security standpoint, this password is pretty much like leaving the keys to your house in your mailbox, hidden among ten or twelve other keys: it’s not going to slow anyone down for long. Even “buff@l0” would be better, and “Buff@l0h3rds” better still; the latter is like hiding the key in your mailbox among several thousand other keys. Most burglars would quickly give up and move on. (Hope you remember which key’s yours!) No wonder that the UNIT brass in the episode were so quickly neutralized, if their security is this sloppy.
The idea of a U.N. website being able to tell a UK submarine to launch a missile on seconds’ notice is not any better. Imagine someone, upon gaining entry into your house with that mailbox key, being able to give your local police unquestioned orders to start arresting local citizens – without warrant – from your phone line. If you’re the mayor, you might maybe be able to get away with that briefly; but the U.N. certainly isn’t the mayor of the U.K. It has to go begging hat-in-hand to the British government just to get a few thousand troops at a time. Of course, in the 1970s, the world had trusted UNIT with the launch codes for its nuclear weapons as an insurance policy, so perhaps the world’s militaries are still doing the same in 2005…
The Slitheen plan is, as happens so often in alien invasions, crap. Earth’s nukes in 2005 could certainly make the planet uninhabitable, but wouldn’t really convert the entire surface to a ‘radioactive cinder’. The contaminated soil, rock, and water would make lousy spaceship fuel: we already understand well what materials make good fuel for reaction engines, and can make keen guesses at the needs of faster-than-light engines. Converting the planet to antimatter would make more sense if one’s looking to power space battleships and cruise liners, but our nukes certainly wouldn’t do that.
As it is, our nuclear reactors produce radioactive waste that isn’t really of much use. Some of it goes into superdense armor and projectiles for our war machines (and that has its own problems), but there’s no fueling problem this waste would solve that other material doesn’t solve better. And how annoying for the Slitheen is it going to be to mine, process, and ship the radioactive soil from Earth? They sure won’t be using us as slave labor: we’re all dead.
The big problem with alien invasions is that almost anything the aliens could possibly want from us is just as easy, if not easier, to get elsewhere. It would be like flying to Paris and taking on a couple of squads of their police for the privilege of mugging a little old lady for a bag of hot dog buns. Someone (maybe the “Predators” of movie fame) might find that entertaining, I suppose, but it’s just not necessary.
The Slitheen insist they’d become ridiculously rich from the sales – why not invest a little, and buy the lion’s share of the Earth’s nukes, then use them on some easy-to-harvest asteroids? I bet the Russians would gladly rid themselves of some of their useless warheads, especially in trade for high technology they could market to the rest of us or convert into more practical weapons for Earth conquest.
Moving on: late in the two-parter, the Doctor gives Mickey a CD-ROM that will erase all mention of him from the Internet. That’s fine, except a virus that will work equally well on all the different operating systems currently composing the Internet would be a nice trick, and sure wouldn’t do much to offline digital and hardcopy storage. Future episodes suggest that it didn’t work anyway, so the Doctor may have overreached himself. It would almost have been more convincing if he had zapped Mickey’s cable modem with his sonic screwdriver and declared, “I’m no longer recorded in Earth’s computer network.” (Well, no… not really.)
Lastly, something I’ve discussed elsewhere but care to repeat here. The fictional United Nations Intelligence Taskforce was introduced to Doctor Who in the 1970s, back when SF writers still seemed to think it would be more productive for the human race to work together on world-threatening issues. Writer Russell Davies killed its senior staff in this episode, potentially implying the end of the organization (to be replaced by Torchwood, perhaps). However, it later reappeared as the “Unified” Intelligence Taskforce, with Davies claiming the the real U.N. had written him and asked for the change.
Now, the U.N. has been portrayed in fiction since its beginnings, often very unflatteringly. (In Rapture storytelling, it often becomes a tyrannical world dictatorship, for example.) The idea that after thirty-five years, someone at the U.N. suddenly objected to the organization’s positive portrayal on a slightly cheesy SF series astounds me. I find it far, far more plausible that RTD just didn’t like the idea of UNIT – wanting to switch to a more British organization – and for his own reasons chose this story to support the change. But I suppose we will never know for sure, and it’s canon now… until the next retcon.
EDIT: Actually, I just had a thought about the change: perhaps there is some weird copyright on potential merchandising of UNIT emblems, toys, and such by the BBC. This still sounds shaky… the Japanese are still labeling Macross toys ‘U.N. Spacy’ (space army), and I’d not think I’d have to ask Germany’s permission to market a “German Army Toy Soldier”, but international copyright is a strange thing. I could imagine it would be just easier to market the Unified toys without having to give the U.N. a cut, or a preview, or whatever. I’d probably believe this story if they tried it on me.
Next time: a superior episode in every way. EX-TER-MIN-ATE!
The Science of Doctor Who: s01e03, “The Unquiet Dead”
For the first time in the new series, the TARDIS heads into the viewers’ past. Because of this, there are only two science-fiction concepts in the story: a “space-time rift” and energy beings who can inhabit gas clouds and dead human bodies.
The Cardiff Rift has been described as a wormhole, a gateway, a place where disparate parts of space and time meet, allowing beings and objects to travel from one part to another. While wormholes are solid scientific theory and not seriously challenged, they are also transient, unstable, and not big enough to send a water molecule through – much less a complex construct such as a mind or a body. On the other hand, these are certainly staples of science fiction; there would be no DS9 without them, just to name one example. So it’s realistically bad science, but like FTL drives, we can probably wave that issue away.
The energy beings are another common SF trope, but one where I have trouble suspending belief. Setting aside any question of souls, here on Earth, a person’s mind needs a brain and a body to inhabit. Computer software needs hardware on which to run. A radio signal needs a transmitter to generate it, and a receiver to play it back; none of these ‘information patterns’ interface with our world without using something physical. Otherwise, it’s like trying to pull spaghetti out of the pot using the beam of a keychain laser pointer.
And a cloud of gas makes a poor carrier for information. Gas is random, disorganized, subject to disruption by currents and slight temperature variation. Try to use a gas cloud to store your financial spreadsheets, and you probably won’t be happy with the results for long. But the other option in the episode isn’t much better…
At first glimpse, the idea of the loose minds taking over corpses seems an obvious one – the original owner isn’t using it, right? But centuries of embalming technology has blinded modern humans to one fact: bodes decay. Shortly after death, various chemical processes in a body are no longer inhibited or controlled; it doesn’t take long at all before eyes are useless for seeing, internal organs are useless for digesting food, brain tissue cannot carry electrical charges, and muscles will no longer flex and pull. And embalming only disguises these processes, or sometimes makes them worse! A loose mind somehow settling into a corpse’s body would find itself extremely frustrated in short order, unable to use it for any of the most basic functions.
(Yes, this means that all zombie movies are complete BS. But no one watching a zombie flick cares, so we’re good.)
Now, it could be some sort of telekinetic puppetry, such as the Nestene Consciousness used two episodes ago. But specially designed plastic mannequins still seem to make better vehicles than decaying bodies. And again, what are the Gelth aliens using to generate the telekinetic forces? The Nestene at least had a giant organo-plastic brain to work with.
In summary, we’ve got two almost certain impossibilities. Both of them are common in SF, so not many folks are probably going to get hung up on either, but they are bad science nevertheless. And in an unrelated note, why can’t the aliens ever just ask for help? The Doctor would bend time and space to help out if they just asked nicely. Stupid aliens.
The Science of Doctor Who: s01e02, “The End of the World”
Of course, I say “every day or two” and immediately, life keeps me from paying much attention to any writing for a while. That, and I needed to find my archive copy of the episode to check out a few details.
This go-round, the main science-fiction idea is that the Doctor has taken Rose forward five billion years or thereabouts to watch the Sun engulf Earth. (It’s a little morbid, but then the death of homeworlds is weighing on the Doctor’s mind these days.)
The timing’s about right, and Rose shows off some basic science knowledge when she points out that a) this should be a slow event over epochs, not an afternoon’s happening, and b) the Earth’s continents should be wholly unrecognizable now due to plate tectonics. Good for Rose! The Doctor glibly responds that gravity satellites have been holding back the sun today, and –
Wait. Wow. The technological civilizations of five billion years from now have the ability to keep dead stars from expanding. I mean, sure, no problem, five billion years; but an understanding of physics at that level implies they can do almost anything with energy and matter that they want, to the point where the space station and shuttles displayed would have to be utterly rustic and quaint. Maybe the whole ceremony is a bit of a LARP, like visiting Colonial Williamsburg is for today’s Americans.
– and that the “Trust” put the continents back as they were five billion years ago, for some sort of aesthetic reasons. Again, I guess since those are basically the continental shapes upon which Humanity evolved and reached the stars, perhaps it’s some kind of nostalgia thing. On the other hand, Earth’s continents aren’t a sliding tile puzzle. Much of the familiar coastlines, mountain ranges, and other geographic features would have been erased by time, and the Trust would have had to reconstruct them from scratch. (But hey, they can keep dead stars from expanding, they can do that too.)
This is not really a scientific observation, but comments of the Doctor’s and Cassandra’s later imply that the economy of the galaxy is still capitalist. I can hardly say that’s impossible, but with the galaxy’s suns pumping out free energy to anyone with a solar collector, and uncounted myriads of lumps of ice and rock and mineral wealth scattered throughout the arms for the taking, and the aforementioned technology levels: well, their version of capitalism must be fairly interesting.
Back to the science. Lady Cassandra. Yeah.
It’s kind of interesting how Cassandra moves her eyes and lips without any muscle tissue. Also, it’s interesting how her eyes pass information to her brain with no detectable optic nerve. (Our optic nerves are thick, obvious things not unlike organic coaxial cable.) Also, her mouth would be useless as a speaking device, since there is no jaw, tongue or vocal cords for making sounds, and there are no lungs to move air through her mouth so those sounds would be audible. Also… also… also… yeah. Lady Cassandra is, at best, a Disney robot puppet being manipulated by the brain tissue beneath. Too bad no one thought to put an automatic misting system on the frame from which the puppet’s hung. Oh, I guess it’s possible that she has nanotech implants for all this – again, the tech levels of this episode are rightly the tech of miracles – but it wouldn’t do anything for her already shaky claim of being ‘pure human’.
That’s a pretty ridiculous claim, anyway. The episode never says how old Cassandra is and the later “New Earth” doesn’t help, but we know from “The Empty Child” that humans began eagerly copulating with the rest of the galaxy’s sentients at least by the year 5,000. From the genetic viewpoint of the year 5,000,000,000, it’s a moot difference. She’d have be ‘pure human’ by some overly-specific and arbitrary definition she made up for the purpose.
Side note: it’s mentioned in one of her two appearances that she transitioned from male to female. By the year 5,000,000,000, one would expect that procedure to be so effortless and routine that people could change bodies like designer clothes if that was their thing. In fact, you’d really expect Cassandra in this episode to look completely like a prime specimen of 21st-century humanity; such a body could be re-spun from her DNA pattern (with desired tweaks) whenever the old one wore out… or just got boring.
So, the upshot is that I find the artificial compression of a star more convincing than Lady Cassandra. In science fiction and fantasy, sometimes the high concepts work far better than the baser ones.
Next time: an episode with, really, not a lot of science in it.
The Science of Doctor Who: s01e01, “Rose”
In 2005, Russell T. Davies brought Doctor Who back to television screens, and he did a wonderful job. The show’s ratings reached unprecedented heights, and our favorite Time Lord gained fans he’d never have been able to reach in the old days. Whovians never had it so good.
But one thing hadn’t changed in the years since the old show went off the air. Back then, most of the science in this classic work of British science fiction came from the magazine articles and the uncommon TV special on new discoveries in astrophysics. And that was okay, really. But this is the 21st century: there are science cable channels, science blogs, science celebrities, and the fairly accurate and up-to-date Wikipedia. Anyone writing for TV should be able to get at least the freshman science right, if only to give it lip service before violating it.
So here, I’m going to look at the science of individual episodes of the new Doctor Who. I’ll not spend a great deal of time on character or plot concepts in an episode unless, you know, I feel like it. And I may not worry too much about core concepts of the show like the TARDIS: like warp drive in Star Trek, if it’s BS, it’s BS upon which the series is built, so it gets a pass. And just because some science may be dubious doesn’t mean it’s a bad episode… unless the plot depends on the science in question…
So, “Rose”. The main science-fictional concept here is that a giant plastic alien brain is animating shop-window mannequins to terrorize the shopping malls of London. The episode doesn’t make this clear, but the Nestene Intelligence has been to Earth twice before in older episodes. In those attempts, it uses a ‘realistic’ puppet (like Mickey this time) to take over a plastics factory (Auto Plastics the first time), which it uses to make the dummies and ship them around the city; we have no reason to assume the M.O. is different this time.
This explains how a mannequin would have a gun hidden in its hand: the Autons have them built in when they are made in the factory. But the dummies seem to be otherwise just like ones used today, perhaps with different plastics that make them easier to animate. Based on the antics of the loose arm in “Rose”, we gather that the dummies don’t need any other sort of special organs – brain, individual muscles, consumption/storage – to do their jobs.
This suggests that the main Nestene consciousness is doing all the work remotely, controlling them telepathically and physically moving them with transmitted telekinetic force, like a child playing with hundreds of action figures at once. This fits in perfectly with the episode’s plot: the Nestene needed an amplifier array to blanket the city, and once it was defeated, the entire army collapsed like abandoned fashion dolls. Plastic’s a good choice, by the way, for animated puppets. Since plastic is composed of long chains of molecules, called polymers, one can imagine the chains coiling and relaxing like animal muscle to move the puppet around.
Telekinesis is a great science-fiction tool: since we have no evidence of anything like it existing in reality, a writer can have it function however convenient. We can use the laws of physics and biology to say a few things about telekinesis and telepathy: no one has yet suggested a method for such forces to be generated and received that has held up to experiment. Also, animals do not evolve the ability to generate directed radiation in the forms we do understand, since it’s always more energy-efficient to do your work in other ways: for example, communication by sound waves, or by color and motion, takes far far less energy than producing radio waves. There isn’t an organism on Earth that doesn’t have a limited energy budget. On the other hand, an advanced organism may find a way to add those abilities artificially to itself, so we’ll let the Nestenes have that one.
Finally, I do want to touch on a new attribute of the TARDIS: the outside doors. In the past, it was often implied that the TARDIS had inner and outer doors, with a mysterious discontinuity between them – mainly due to limitations on television effects technology. And the interior doors were generally portrayed as comfortingly massive. Now, the TARDIS appears to have a simple set of flimsy wooden doors between the console room and the universe, which would concern me quite a lot as a traveler. I think we must assume, based on the Doctor’s assurance that they’d resist “the hordes of Genghis Khan”, that either those doors are far more solid than they look, or that there’s plenty of super-science reinforcing and protecting them – or both. It’s fun to now be able to look into and out of the TARDIS whenever we want, so that’s good enough.
Next time: blah blah blah… and I feel fine.
