Tuesday, 30 August 2011

#26 Zombie-Proof Housing: Property Guide to the Apocalypse

With house prices taking a dip there has never been a better chance to get into the market. And with the zombie apocalypse only being a matter of time, you want to make sure your new dream home is ready for anything.

The idea of buying your very own post-apocalyptic bolt hole is a staple of science fiction satire. Back when he was good, Ben Elton wrote a novel called This Other Eden which was about a company selling personal biospheres for people to move into to live out the looming ecological breakdown.

The videogame franchise Fallout is full of hokey 50s style adverts for massive underground vaults where you and your family can move into to avoid the bombs dropping. 

It’s fertile ground for satire- the idea of society facing its looming destruction by trying to sell yet more consumer goods is just the sort of over-the-top, extreme, exaggerated metaphor for consumerism that sci-fi does so well.

So, here are some reviews of real life post-apocalyptic residences that you can actually buy with real money.
Satire is dead.
And the best part is- they will only rise in value when they’re the only structures still standing.

1: The Safe House

If you’re a zombie nut who spends any amount of time on the Internet (and according to Google analytics, you are) you’ll have probably seen this place already. Built by Polish architects KWK Promes, the safe house looks like the sort of spacious, contemporary property you would expect to see lived in by a successful movie star or cocaine dealer. However, at the flick of a switch the building transforms Tracy Island style into a locked down zombie-proof fortress of doom.
Just don't get caught in the draw bridge.
The architects say: “The innovation of this idea consists in the interference of the movable walls with the urban structure of the plot. Consequently, when the house is closed (at night for example) the safe zone is limited to the house’s outline. In the daytime, as a result of the walls opening, it extends to the garden surrounding the house.”

What we say: Okay, this place is pretty secure, you’re probably going to be living a pretty luxurious life in there and there’s room for you and your whole family. There’s the problem. It’s not all that hard to make a home secure from zombies, with a bit of work you can make a farmhouse or even a pub a secure place to hide from the zombie menace. That’s never what gets you. What gets you is the people you’re with, the tensions, and rivalries, the silent power struggles.
How long do you think you’ll last through the end of days if you’re stranded with people you can’t make it through Christmas dinner with?
It keeps the zombies out, and the sound of screaming in.
2. Vivos Shelters
Terra Vivos’s facilities- advertised here in a video heavily influenced by Battlestar Galactica’s opening credits, are probably the closest thing we have yet to Fallout’s Vault-Tec facilities.

Their website is a masterpiece of marketing- few companies selling products this high end would have the balls to actually include a “Prophecy” section on their website, as well as a list for the most “viable scenarios” for your imminent fiery death (zombies aren’t on the list, but the 2012 predictions are). It even has helpful countdown clock to the 2012 apocalypse on the left hand side, like some sort Armageddon oriented Ebay.

The service they provide is called “Life Assurance” which is a bit like “Life Insurance”, and so sounds like a real, legitimate business.

But Vivos doesn’t just offer one shelter, oh no! In this day and age where you car, mobile phone and choice of music player say so much about you, would you settle for anything less than fully personalised salvation?

They say: “At 137,000 square feet, spanning four levels, this facility will be the largest, strongest and most defensible Vivos shelter in North America, accommodating over 900 people for up to one year of autonomous, underground survival.  It will also be the first Vivos shelter to come online, in early 2011.  Due to the massive size and economies provided by the scale of this shelter, Vivos is able to offer a limited number of membership spaces at just $25,000 per person.”

We say: That’s right, you don’t want to die because of some piddly family drama. You want to go what professionals call “The full Lord of the Flies.” Still, this looks like some pretty sweet digs, kinda reminds me of the laboratory they lived in in the Andromeda strain. Of course, the stuff that’s actually been built so far looks like this:

Which is less appealing. Still according to their timer as of writing they have 478 Days, 02 Hours, 36 Minutes, 08 Seconds Remaining, so as long as there isn’t an unexpected apocalypse before then, you’re laughing. The only real problem here is the price. They quote $25,000 per person here for their Nebraska facility, but at the Indiana facility prices are already at $35,000 per person, with prices set to rise to $50,000 once the initial spaces are sold. That’s a pretty hefty investment, and even if you think that’s a small price to pay to survive the coming hell storm, if you’ve got a family you need to seriously consider whether you love them that much.

And of course, the shelter is only designed to keep your sheltered for a year. If Fallout 3 taught me anything, it’s that if you live in an underground bunker through the apocalypse only to climb out onto the surface of a blasted Earth later, you’re basically going to get your lilly-white ass handed to you by all the Mad Max types who just stood outside and took their nuclear blast like a man.

They say:“Vivos is now offering an economical shelter solution for the average person and family. A recent survey of Vivos members revealed that nearly two-thirds cannot afford to purchase a share for themselves and their family in one of our First Class shelters. With our goal being to save as many lives as possible, Vivos is reworking one of the largest facilities to accommodate 1,000 people at a very affordable rate of just $9,950 per person. Now, virtually anyone can afford a boarding pass into an impervious Vivos underground shelter to survive whatever man-made or natural cataclysms may lie ahead.”

We say: Okay, so it turns out you did love your family that much, and so rather than spend 30 grand on living it up in 5 star cursed-Earth luxury, you decided to split it three ways and get a less flashy accommodation for you, your partner and the least obnoxious of your two kids.
For that, you get... well you get four bunkbeds and a curtain:
Pro tip: For maximum domestic harmony arrange a "Wank rota" where three of you will be out of the room at pre-arranged times.
Still, at $9,950 per person? With property prices the way they are now, I’d actually be up for that if they let me move in straight away.

3. My House
It has a lockable front door, barbed wire at the rear garden fence, a wide selection of garden implements for self-defence, plus a nice old man lives next door who owns and knows how to use a machete. Plus I’ve been reliably informed by the British government that the cupboard under the stairs is a perfectly adequate fallout shelter.
Yeah, I’ll be fine.

Monday, 22 August 2011

#25 Flipped: A Dark Glimpse of Mankind's Future

This was a story I wrote for a Cabaret night at the Birdcage in Norwich. It is a story about a different kind of apocalypse, so I thought it would be in keeping with this month's non-zombie theme.

Ladies and gentleman, consider, if you will, the End of Days. There has been much talk recently of Biblical and Mayan prophecies, much debate over whether we will die at the hands of zombies, or robots, or, most recently, chimpanzees. But I am here tonight to tell you that the truth is far more startling, and more terrifying, then you could have possibly imagined.

Before I begin this tale, let me assure you that the facts presented here are 100% scientifically accurate. I know, because I looked them up on Google myself. So, if you're sitting comfortably, let me show you a glimpse of mankind's dark future...

It is the year 2036, and the world is a very different place. Meet Terry, at 25, Terry is one of the last people left who still remember the old world. The world of men. Now he’s a soldier- all surviving free humans are soldiers. Today he is crawling on his belly through the rubble of a destroyed office block, clutching his weapon to his side. The sun is setting behind the ruined crags of a once great city, and Terry, Terry is being hunted.

Still, Terry has been hunted his whole life, and nobody has caught him yet. Using stealth techniques learned from a lifetime of scavenging the wreckage of the old cities, he circles his enemy, keeps beyond the reach of its senses. Eventually, he’ll find a safe vantage point, and then the hunter will become the huntee.

He finds his spot, a still-standing concrete pillar that offers a clear line of sight to the enemy. It’ll mean leaving cover, but if he’s quick enough, it might just work. Terry risks a glance around the edge of the pillar. The enemy is there, watching with tiny black eyes. And it’s smiling. That’s the thing Terry hates most of all. The enemy is always smiling.

TRUE SCIENCE FACT: Dolphins are one of the only species known to kill for pleasure.

It was our own fault of course. We trained them. From the 1960s onwards the Soviet and US navies were known to be training dolphins to hunt out mines, and rumours abound that they were trained to plant them as well.

But that’s the thing about dolphins. They communicate. They spread the word.

The first anyone knew anything was wrong was the day that none of the tuna fleets returned to port. Not long after that the oil rigs started going down- the few survivors reported spectacular explosions that strangely managed to avert any spillages.

As we panicked over the looming energy crisis and bickered among ourselves, they struck. Nobody knows how they constructed the exo-skeletons- the strange fish bowls with mechanical limbs, armed to the teeth. Some theorised that the dolphins had evolved an advanced form of telekinesis. Others said they had crab slaves. By the time New York fell and Sheringham became a death camp, it was all academic anyway.

TRUE SCIENCE FACT: The ancestors of the dolphin had claws. As dolphins evolved they did away with the claws because they didn’t need them anymore.
Let’s return to Terry. He’s still hiding behind his pillar- the quick glimpse he stole was already a huge risk, and he doesn’t want to show himself again until he’s ready to strike.

Keeping out of sight, Terry arms his weapon.

Not long after the initial uprising, we discovered that bullets were useless against dolphin technology. For a while it looked like our cause was lost- some argued for a nuclear solution, but after the hijacking of Trident nobody wanted to risk escalating the conflict to that level.

Then, a brilliant engineer in the resistance realised we could breach the dolphin defences using a long, spear-like projectile fired with some manner of pressurised gas or spring. The ‘poon, as it became known, was soon our most valuable weapon.

Like all good soldiers, Terry loves his ‘poon. He keeps his ‘poon clean and in perfect working order, knowing that at any time the ‘poon could be his only hope.

Readying his ‘poon for action, Terry edges around his cover and takes aim. No sooner has he locked on than he notices an area of red lights dotted across his chest-plate. The dolphin’s echo-location spotted him the moment he broke cover. Terry dives for the ground as a rain of fire descends on him.

TRUE SCIENCE FACT: Based on the bodies of murdered porpoises and infant dolphins, it’s believed dolphins can use their echo-location to pinpoint the individual organs in a body.

Despite our near total defeat, even now the human race doesn’t face total extinction. Although merciless in their subjugation of our race, the dolphins seem to have a lingering affection for some of us. They have a particular affinity for pregnant females, and some children. These chosen few are given resplendent quarters and the best food rations, although they are regularly called before a court of their dolphin masters. Sometimes they are asked to perform tricks, other times the dolphins simply want their company. Some dolphins apparently find it “soothing” to swim with humans.

As for the rest, the adult males or anyone who the dolphins believe is overly grouchy, well, they are simply sent to processing camps. Humans go in, tins with smiling human faces on the labels come out. No human has yet deciphered the writing on the tins.

TRUE SCIENCE FACT: On average 37 people die a year from dolphin attacks. There are 60 reported shark attacks a year. It should be noted, sharks are not intelligent enough to cover up murders.

Terry is lying battered and bleeding in the dirt, but still alive. He’s lasted as long as he has after the dolphin apocalypse not just by being tough and being careful, he’s also made a habit of being incredibly lucky.

The dolphin is approaching now, one robotic step at a time. With every crunch of its feet against the rubble, there is a sloshing noise as the water rolls around its cockpit. The dolphin intends to find Terry’s body, and using its echo-location, determine whether his organs are still functioning.
Terry glances down, and realises his hand is still on his ‘poon. He heaves the gun into place, and takes aim. As the dolphin soldier steps into view, Terry fires the harpoon.

Laughing, Terry clambers to his feet, and stumbles over to the body of his fallen nemesis. As he stands over the crumpled exo-skeleton, there is triumph on his face. Looking at his tiny, dark eyes, and the smile that stretches from ear to ear, you could be forgiven for wondering if maybe, just maybe, mankind is the real dolphin.

Suddenly, the smile vanishes. Terry can see the twisted metal, the shattered glass, the spilled water, but he can find no sign of the dolphin pilot. Behind him, he hears a whistling, clicking sound.

TRUE SCIENCE FACT: Nobody knows for certain that dolphins can’t levitate.

Monday, 15 August 2011

#24 Rise of the Planet of the Apes: Hollywood Loves Alzheimers

In-keeping with this month's "Apocalypses that don't include zombies" theme, this week we're going to be looking at the Ape-Pocalypse.

I’ve been hurt before. It was 2001, I was 16 or 17, an innocent, almost naive soul full of hope for the future. Then one day, I recommended to a friend that we go and see a film. That film was a remake of one of my favourite classic sci-fi movies directed by someone whose other films I liked. It seemed like the perfect match. Look! I didn’t know! Okay? I was young! I didn’t know!
Fuck you forever, Tim Burton
I would never be the same again after that fateful day. The Planet of the Apes remake featured Mark Wahlberg with a face marginally less convincing than the prosthetic ape masks, the moral that racism is probably just the fault of like, one bad person, and a twist ending where... the bad ape becomes Abraham Lincoln? Or something?
More like APE-braham Lincoln! Am I right?
So you can understand, I was cautious when it was announced that yet another Planet of the Apes film was being made- Especially since there had been only one decent Planet of the Apes film made after the first one. (It was the third one).

So you can imagine my relief when it turned out that Rise of the Planet of the Apes is not in any way a remake, prequel or reboot of the Planet of the Apes series. Let me explain. From here on, there may be spoilers- although admittedly, none as bad as the bloody cover of the original Planet of the Apes DVD.
The clue is on the left
You see, Planet of the Apes is a story where science is the hero. There’s some not-very-subtle criticism of vivisection, and some light-hearted fun is poked at Darwinism, but at its bare bones Planet of the Apes is the story of some scientists eager to discover the truth about their world, against the wishes of the religious rulers of their society.

Rise of the Planet of the Apes on the other hand, is about scientists who, while trying to find a cure for Alzheimer’s disease, inadvertently make some animals super intelligent, who then turn on the humans. This is not the plot of Planet of the Apes, or the even the ill-conceived Planet of the Apes sequel/prequel Conquest of the Planet of the Apes.

This is the plot of Deep Blue Sea.
A film entirely worth it for Samuel L Jackson's death scene
Deep Blue Sea is not a film with an overriding love of science.  The reason sharks turn super smart and start killing people in that film is because they were being used to develop a cure of Alzheimer’s and the scientists “used gene therapies to increase their brain mass. A larger brain means more protein. As a side effect the sharks got smarter.” In Rise of the Planet of the Apes, the main character boasts that “Our therapy enables the brain to repair itself.”

In Planet of the Apes, Dr. Zaius, the religious leader of the ape society is shown to argue “There is no contradiction between faith and science... true science!” and when Charlton Heston goes in search of the truth, Zauis warns “Don't look for it, Taylor. You may not like what you find.” Throughout Planet of the Apes it is made clear that if somebody argues that “there are some thing man (or ape) was not meant to know” it is because there is something that they want hidden, that ignorance is being maintained for a purpose.

In Rise of the Planet of the Apes, the sensitive, hot looking veterinarian who becomes the love interest says “Some things aren't meant to be changed.” And by some things, she means Alzheimer’s disease.

In order to ensure a balanced and fair review I thought it fair to provide an Ape perspective on the film, and so I invited our blog’s favourite subhuman primate along to the film- Hello Bear bassist Tom Harvey. Tom exhibits the basic problem solving and communication skills of an untrained chimpanzee, so his views would naturally be valuable.

T: I have a degree in biomedical sciences.
He likes to fling poop!
In exchange for some bananas and dried fruit, Tom used a series of primitive hand signals to raise the following objections:

1.    Show me a life saving drug which has taken 5 years to develop, in the modern age. Please, I'm intrigued to see if any have gone to trials on non-human primates in such a short space of time.
    2.    The term "statistical significance" seemed to have been ignored - One positive result in apes, compared to several negative, would never leda to trials in humans.
    3.    You can't just wander into a lab and steal chemicals, even if you're a lead researcher.
    4.    Likewise, you can't just walk into a lab and steal animals - ask PETA.
    5.    If an animal was pregnant before or during testing, this would be spotted.
    6.    Scientists (to my knowledge) won't buy any old animal from any old criminal.
    7.    A shareholder can't just walk in to a lab and say "test on humans, to make me money".
    8.    Where were the published results of the animal trial? I'm sure the 3rd reviewer (and 1st and 2nd) would have had something to say about the methodology.
    9.    I'm pretty sure it's frowned upon to have "veterans" of testing (with regards to test subjects). The regulatory bodies might have something to say about this.
    10.    Speaking of regulatory bodies….where were they? For the lab, and the animal sanctuary.
    11.    No randomisation of the animals in the studies either - they were specifically picked out (by the CEO of the pharmaceutical company - even more ridiculous)
    12.    The scientists didn't seem to be "blinded" to the treatment groups either.
    13.    Were there control groups? No mention made.
    14.    The claim is made that apes have "much stronger immune systems than humans". This is not something I've ever heard previously.
    15.    The virus somehow manages to alter the genes in many different subtypes of cells - in the brain, the gametes, and in the cardiovascular system. Doesn't sound particularly well designed if it lacks specificity.
    16.    Also, the scientist seemed to be good at talking to women….no way.

I assume these are things he learned while researchers unsuccessfully tried to train him to release food pellet by press a button.

Still, what the hell? It’s called science fiction, not science... is... real... thing. What does it matter if they got a few details wrong while pushing a message that scientists are irresponsible, hubristic madmen who will stop at nothing to create their precious medicine?

Well, the fact is, these stories are where a lot of people get their idea of what science is. Hell- the only reason I was interested in science as kid was because I assumed my job would be pretty much the same as Doctor Emmet Brown’s.

Not pictured: The "control" DeLorean
And this has very real consequences for the way science is reported. Only last month the Daily Mail warned that a “Planet of the Apes scenario” could result from scientists researching with human-animal hybrid embryos- that live in a petri dish for 14 days before being destroyed. Some scientists believe that this could lead to a supply of stem cells that could be used to investigate debilitating and so far untreatable diseases including, among others, Alzheimer's disease.

Objections to this research come from religious groups of the Dr. Zaius variety, and from those who think movies like Rise of the Planet of the Apes are a documentary. There are important ethical questions that arise with the dawn of any new research- This is why there exist ethical committees, because believe it or not, scientists put a lot of thought into how their research can be misused. And we’re right to ask questions about that research. But films like this don’t further that discussion, all they really do is continue demonstrate just how much Hollywood loves Alzheimer’s.

Monday, 8 August 2011

Working the Time Machine: Writing Time Travel So It Makes Sense

I've got quite a busy week on this week, and the movie I wanted to blog about isn't actually out yet. So this week I'm posting something that has nothing to do with apocalypses of any kind. This was a talk I gave at a conference at the University of East Anglia a couple of years ago. So, here's my guide to writing time travel so that you don't end up with any of those annoying paradoxes.

Working the Time Machine: Writing Time Travel So It Makes Sense
When H.G Wells first conceived of the Time Machine, it must have seemed like a fairly simple conceit. If you have a character in the present day, and you want him to have an adventure with dinosaurs, or medieval knights, or futuristic robots with laser guns for hands, have him hop into the time machine and it will take him where, or when, you want him to go. These stories are usually very straightforward, the past is almost literally another country.

But it wasn't long before writers worked out that you could influence events in this other country, and by extension, alter the nature of the present. Puzzlingly, a lot of the time, the first thing people wanted to change was that their own grandfathers had never been shot. I don't know why this is, personally I like my grandfather, but once you open up that option, time travel has some mind-boggling implications. If your grandfather dies before your mother or father is conceived, they won't be born, so you won't be born, so just who's going to shoot your grandad?
Because fuck that guy
For the writer, there's clearly the potential for some good storytelling here. But from the get go you've also got some major problems. One thing causing another is pretty much the simplest definition of a story you can get. If you start mucking about with that, you better know what you're doing, because events can get tangled up in themselves, very quickly.

That's what this talk is going to be about. If you're writing a story about time travel there are various models you can use to explain how cause and effect work, and we're going to go through them. We will look at the restrictions these models place on the writer, the options they give, and the loopholes they create.

What Happens, Stays Happened
Let's start with what might be the simplest model of cause and effect. What happens, stays happened. You can't change history.
No matter how good an idea that might be
You take your DeLorean back in time, try to shoot your granddad, but you miss. You try again, but the gun jams. You get a new gun, shoot him in the head at point blank range, and it turns out he wasn't your real granddad, and if you'd asked your grandma before you set out, she would have told you that that was the way he'd always died.

This is a popular model, a lot of scientists are big fans of this model, less for any scientific reason than because of a vague feeling that anything else would just get silly. They may be right, but I intend to show they've vastly underestimated people's potential for silliness.

Often this rule will be taken even further, and someone trying to change the future will inadvertently cause the thing they wanted to prevent. You try to kill your granddad, but some hilarious slapstick sequence of events mean you actually save his life.

This is an old plot, you can date it back to before Oedipus's dad had his son left on a mountainside because he'd heard that when the kid grew up bad things would happen. This is far from the last reference to Oedipus in this paper.
Why do all my blogs end this way?
For the writer, this model of time travel can work nicely. As I said earlier, what happens, stays happened, you don't have to worry about things your character does in Chapter Twelve wiping out what they did in Chapter Three. Actions have consequences, and those consequences are permanent. There's no hope of a quick fix when your character goes back to alter history to suit themselves.

At the same time, although your story can't go back and negate itself, there is still a lot of room for plots to loop back on themselves, and often the story you end up with will be far from linear. If you're going to attempt this sort of story, it's a good idea to be good at plotting. Often, these stories will end up following the structure of a detective story, starting at the end, and spending the narrative working out how the protagonist gets there, but this is just the simplest structure this sort of story can take.

An excellent example of the use of this sort of time travel can be found in The Time Traveller's Wife.
You know, I didn't know how creepy this paper's underlying themes were until I started illustrating it
For those of you who haven't read the book or seen the movie, the Time Traveller in question is Henry DeTamble, a man who frequently finds himself hopping backwards and forwards through time, with no control over where or when he will end up, or for that matter, any clothes when he gets there. A lot of time travel seems to involve nudity. I don't know why.
Also, everyone seems to come out of time travel looking ripped
The story switches between being narrated by Henry, and his wife Clare. Henry meets Clare when he is twenty-eight and she is twenty. Clare meets Henry when she is six and Henry is thirty-six. They both experience exactly the same events, but in a different order. They also have to deal with the knowledge that their future is set and immutable. Henry regularly travels back to events in his own past he would want to change – his mother's death in a car crash, an accident he sees at the ice-rink, and the time his father walks in on him as a teenager making out with his future self. He is powerless to prevent these things from happening.

But this doesn't render Henry and Clare completely powerless. It doesn't stop them from being able to win the lottery, should they ever want to. It doesn't stop them from using information about a doctor's unborn child to manipulate him into taking on Henry's case. And it doesn't stop Henry from giving six year old Clare a list of dates, telling her exactly when and where his trips through time will bring him to her.

We'll come back to these tricks in a second, and see just what we can do to push them to breaking point, but before we start getting pleased with how clever we are, I'd just like to point out what the time travel manages to do for the part of the story we're actually supposed to care about, the relationship between Henry and Clare.

For a start, we get to see Henry and Clare's relationship from several different angles. Every time Henry and Clare meet they are different ages, knowledge of the past and future is divided up differently between them, and this affects the way the relationship works. For Clare, Henry goes from being a cross between a parental figure and an imaginary friend, to a teenage fantasy, until eventually he becomes Clare's life partner. On the other hand, when Henry meets Clare for the first time, she's a complete stranger who already knows a large part of Henry's future before he does.

The other notable use time travel has in this story, is something sci-fi has always been very good at, taking a metaphor and taking it absolutely literally. A relationship is full of metaphorical time travel, you spend a lot of it in your imagined future, with the fantasies, hopes and fears that accompany that. Equally, nostalgia, grief and regret can draw you to the past. For Henry and Clare, this isn't just flowery language, it's a physical truth.

Which is all very touching, but we're not here to talk about love stories, we're here to screw up the laws of causality, so let's focus on one of the tricks this book pulls off- going back and doing favours for yourself in the past. If you remember your future self helping you out before, you're not changing history, you're just completing a loop. Once you allow for that, we can really start to enjoy ourselves.

My personal favourite example of this trick is in Bill & Ted's Bogus Journey, probably the third greatest film about evil robots from the future ever made. The Bill & Ted movies follow the adventures of the Wyld Stallyns [sic], who will eventually become the greatest rock band who ever lived, saving the environment, bringing about world peace, and making the air guitar the standard form of greeting.
These films were so good, Keanu Reeves decided to never act again
At the climax to the second film, Bill and Ted face off against the villain who has come back in time to destroy them. It seems that Bill and Ted are doomed, until Bill comes up with a fool proof plan:

“After we get away from this guy, we use the [time machine]. We time travel back to before the concert and set up the things we need to get him now.”

At that point, it turns out a sandbag and cage have been set up to drop from the ceiling, disarming the bad guy and trapping him. The bad guy's response to this is to point out that when he has defeated Bill and Ted, he's going to go back in time and equip himself with the key to the cage and a spare gun, promptly, it turns out he has both those items. Only for it to turn out that the gun is a dud because "Only the winners are going to be able to go back and set things up!" Bill and Ted set up the key and fake gun for kicks.

Despite appearances, at no point is time changed. Bill and Ted had always gone back in time after defeating the bad guy, and the cage had always been hanging in position, waiting for the right time to drop down.

Okay, so let's see if we can push this even further to breaking point with another, entirely hypothetical example.

Supposing, just supposing, that instead of spending the last few weeks studiously researching and preparing this paper, I instead spend the last few weeks playing Halo 3 and watching reruns of The Gilmore Girls. When today comes round, somehow I sleep in until three in the afternoon, and only just have time to get to campus. We've all been there.
It's like a hug for your eyes!
Luckily, as I'm on my way out of the house, I find an envelope on the doormat. I look outside, but there's no-one there, just a couple of flaming tire tracks and a number plate spinning in the road. The envelope, rather handily, contains this very paper. I deliver the paper, and it's a huge success, then slip I out of the building, climb into my DeLorean (did I mention I have a DeLorean?) and travel back in time to this morning. I put the paper in an envelope, push it through my own letterbox, then hop back in the car and disappear.
Then I use my DeLorean to pick up chicks, because Relativity says the DeLorean is the sexiest of cars
Again, this series of events is entirely consistent with itself, past present and future form a neat little mobius strip. But I'm sure some of you are wondering, if that's the case, who actually wrote my paper?

Well, until anyone else steps forward, I'm still going to take the credit.

Robert Heinlein was a big fan of this sort of loop, and pushed it about as far as you possibly can with his story All You Zombies. In that story, a girl grows up in an orphanage, is impregnated by a mysterious stranger, who later turns out to be her transexual future self. The transexual future self then steals the baby, takes it back in time, and drops it off at the orphanage. The girl is her own mother and father, begging all sorts of questions. I told you that wasn't the last Oedipus reference, didn't I?

There are all kinds of tricks and paradoxes you can pull without altering so much as a second of history. However, handled poorly, the unchangeable history has its own pitfalls.

For a start, it can lead to your characters having to behave unnaturally just to keep the plot consistent with itself.

I think it's fair to say that a lot of people, finding themselves in the past, would try to alter history just to see what happened, even if they didn't have a motive for doing so. We're just spiteful like that. If the writer acknowledges that, they will often find themselves creating ever more contrived sets of circumstances and coincidences to keep time on the correct path. You can only keep this up for so long before it begins to stink of deus ex machina, and maybe even end up with people talking about “Time” as an anthropomorphic entity, which I've always felt borders on cheating.
Plus, let's face it, the laws of causality would have to work pretty hard to keep this guy alive
But what if you can change history?

“The future is not set.”
That's a quote from The Terminator, a film that, at first glance seems to follow the standard plot of “go back in time, try to prevent something, inadvertently cause it to happen.” Arnold Swarzenegger goes back in time to prevent John Connor from ever being born, and in the process, accidentally introduces Sarah Connor to John's father. There are even deleted scenes to show how the mangled remains of the Terminator end up inspiring the creation of the computer that will eventually become Skynet and kill us all. It seems like a perfect loop.

But in the first film, James Cameron keeps dropping hints that history can be changed. There's the above quote, from John Connor of the future, there's Kyle Reese insisting that he's from “one possible future”

Then, in the second film, John, Sarah and another Terminator track down the man responsible for building Skynet, blow up all the information relating to it and prevent Skynet from ever coming into being. From a storytelling point of view, this serves several purposes. It handily explains why we didn't all die in a nuclear holocaust in 1997. It allows John and Sarah Connor to have a happy ending, which they couldn't have had if the future was set . And it means we can all pretend Terminator's 3 and 4 never happened.
Wiped from history
For those of you keeping count, Terminators 1 and 2 are the second and first best evil time travelling robot films ever made, and two more examples of time travelling nudity.

Now, in the name of full disclosure I should point out here that I prefer this sort of story. I feel like the stakes are higher if the future is changeable, and it’s easier to become invested in characters who can take full credit or blame for their actions. Of course, having said that, I should point out that if history is changeable, that doesn't automatically imply free will exists. It could just mean determinism is really badly organised.

A Matter of Perspective
Writing a time travel story with a changeable history does give you a lot of options, but it also confronts you with a brand new set of problems. Perspective, for example, now has to be a much more precise tool.  If you can't change history, you can view the story from any angle you like, the actual events will always be the same. If history is changing, that isn't the case.

The easiest solution is to keep your perspective nailed to your time traveller. After all, your time traveller is likely to be the only person to actually notice history changing, so they will probably be in the best position to watch events. They will know how history has changed, what history was like before, and what caused it to change.

Another solution is to place your perspective with a character from the past that's being travelled back to – this is pretty much how the Terminator films work. Again, this is reasonably straightforward. You don't see history changing, you only see events unfold, and how the time traveller is influencing them. The time traveller might explain how history originally unfolded, and you might be able to guess at how things would have turned out if the time traveller wasn't there, but for all intents and purposes you only see the one version of events.

The other alternative is a lot more tricky, and that is to tell the story from the perspective of the future that is being altered. If you're going to do this, you've obviously set yourself quite the challenge, as character's memories will be changing from one scene to another and the reader will often be the only one who can see what's really going on. If you're going to write your time travel story this way, you're going to have be very good at getting information to the reader subtly, and often you'll have to depend on them to fill in the blanks for you.

Of course, it's possible to switch between these perspectives, but if you do you will risk confusing your reader for the sheer hell of it.

Photoshopping Through Time
Regardless of what point of view you're watching from when history gets changed, we're still back at our original question – what's going to happen when you shoot granddad?

One option is you shoot your granddad, and then mysteriously fade away as you've erased yourself from history.

Many of you will remember this version of cause and effect from that other great example of an Oedipal time travel plot, Back to the Future. For those of you who haven't seen this masterpiece of modern cinema, Marty McFly travels back to 1955, and accidentally disrupts his parents' first meeting, causing his teenage mother to develop a crush on him, and negating his own existence.
Having sex with Lea Thompson is widely considered one of the better ways to negate your own existence
We know he's negated his own existence, because on a photograph he's brought from the future he can see his older siblings fading away, one by one, until eventually his guitar playing hand also begins to disappear.
Changing the fabric of causality is just slightly less efficient than using photoshop
Now if we're going to start picking holes in the logic here, there are rich pickings, and that's without even touching the sequels. For starters, you have to wonder what George McFly thought when his third born child came out looking exactly like the guy his wife used to fancy in High School.
It's telling that an earlier timeline, Marty McFly looked more like Eric Stoltz
But aside from that, the biggest problem with the fadey-photograph method of showing how history changes is that when Marty changes something in 1955, it seems to change in 1985 at the same time. You can get this problem quite often when writers think of the past as literally another country. You can trace this right back to H.G. Wells' Time Machine, when his narrator suggests that “even now” the Time Traveller is on some “on some plesiosaurus-haunted [...] coral reef.”

We're going to give Back to the Future some slack here though, and not just because nobody has yet designed a time machine that looks cooler than the DeLorean. Back to the Future is, as the title suggests, ostensibly about Marty trying to return to a time period that hasn't happened yet. Since the plot demands he have some difficulty doing that, he can't keep nipping forward thirty years to see how his actions have affected 1985. Even if he could, it would make for a fairly unwieldy plot. The fading photographs give the audience a shorthand for how events are going to play out.

And despite the title of the film, the central pillar of Back to the Future's plot isn't Marty's attempt to get home. The main story arc is arguably George McFly's. The film is the story of a wimp's struggle to get the courage to stand up to the bully and ask out the girl. Marty is there partly as a catalyst for setting events in motion, and partly to raise the stakes, and make George McFly's teenage concerns a matter of a life and death (or at least, life and not life).

Branching Out
Still, if you want to have a time travel story where history is mutable but your plot still stays internally consistent and there's no “meanwhile, in the future” nonsense, we can do that too. The way we do this, is quite simply, to cheat.

So, let's get our gun, climb into our DeLorean and head back in time to a nice little cafe where your grandfather's just sitting down for lunch. Your gun's in perfect condition, you're going to be firing it at point blank range, and you've performed extensive DNA testing to prove he is in fact your biological grandfather, we have all our bases covered. You walk in, pull the trigger, and before you know it there are granddad brains dripping off the walls.
"And that's what happens when you only put a five pounds in my birthday card, bitch."
At this point, the time line splits in two. There is the first time line, where your granddad finishes his lunch in peace and goes on to have grandchildren who harbour some sort of unspecified resentment towards him, and then there's the new time line, where he doesn't. You're not about to disappear, you're fine, because you're from time line number one, but in time line number two, you will never be born. When you return to the future, it won't be a future you recognise, and nobody's going to recognise you.
For an insanely complicated version of this, see the movie Primer
This version of time travel helps us resolve a whole lot of other paradoxes. Remember the mystery of who wrote my paper? Well now we can solve that one. At some point, there was a time line where Chris wasn't conveniently saved by a postal delivery from the future, and went on to look really quite silly. Unable to live the humiliation down, he decides to actually write the paper, then take his DeLorean and post the paper to his past self. Rather than altering his own past however, that version of Chris ends up creating a new time line, which we've already described. After that, the loop becomes self sustaining, spreading out across various alternate time lines.
Of course, when I tried to redraft it, things got kinda complicated
If you put your mind to it, you could probably even create a loop of the kind seen in All You Zombies, although after a few different time lines, that baby would be seriously inbred.

Of course, even this model of cause and effect has some problems. For example, stories that use this model rarely, if ever, explain what happens to the original time line. Does it break down and disappear as soon as our time traveller leaves? Does it keep going on without him? If it keeps going on without him, then just what is the point of Skynet sending the Terminator back to kill John Connor, and why bother sending Kyle Reese back to stop him? In time line one, Skynet's already beaten. If you think about it too long, it also makes you wonder, just who was John Connor's real dad in the original time line?
He wasn't originally John Connor's father, he was just aiming for the best "Your mum" zinger in history
Your time traveller will also have to be careful not to do anything that will prevent their past self from going back in time. If their past self doesn't get in the time machine, it won't cause anyone to fade away, but now there are two versions of your time traveller.

If you're telling your story from the perspective of the past that's being travelled to, things can get even more complicated. Kyle Reese says he's from “one possible future”. Implying there is more than one possible future. You could feasibly get time travellers from several possible futures, or even the same time traveller coming from several possible futures. Personally I'm still waiting for Terminator/Planet of the Apes crossover, where the hyper evolved apes duke it out with robots to see who gets to overthrow humanity. Basically I want to make Arnold Swarzenegger fight a gorilla.
Come on! I know you've still got it!
We've looked at various different ways of portraying time travel over the course of this paper, but the important thing to remember is that time travel is a story-telling device, it can't make the story on its own. The stories we've looked at have been about a complicated romance, a dweeb trying to get the girl, and killer robots (which can make a story on their own). Time travel allows us to do things with those stories we otherwise wouldn't be able to. We can see relationships you otherwise wouldn't get to portray – how a parent and child might get on when they're the same age, how an ageing conservative might get on with his hippyish, lefty younger self. We can see how characters react to seeing their own future, or how their lives might have turned out differently. But the thing to remember is, if your characters are convincing and compelling enough, your time travel logic can be as sloppy as you like.