Friday, 10 June 2011

The Earnest Importance Of Zombie Plans

I was in the Scout association for fourteen years, and learned a lot about self-reliance, teamwork and initiative.  From day one a Scout's motto has been the famous "Be Prepared".  Prepared for what?  Just about anything is the point.  We were expected to look after the younger kids on camp, lead patrols on mountain expeditions, even run messages for the emergency services in the event of a major disaster.  It's an ethos that has served me well in the last thirty-odd years, and one that is frequently recognised by employers and the like as being a Good Thing.  Despite the whole boys-in-shorts image you have to remember that Baden-Powell based the training on the principles of a specialist military unit.

So where do zombie uprisings come in?  Well, zombie attacks are very close to being a worst case scenario for modern civilization.  The combination of a highly lethal viral style epidemic and violent civil uprising make them very difficult to deal with.  I'll have to admit at this point that I don't believe we'll ever actually see a Romero style Day Of The Dead, but the point is that if you can deal with zombies you can deal with anything short of a direct nuclear strike.  Be Prepared for the undead and you'll Be Prepared for most eventualities.

"Official" attitudes are slowly coming round to this point of view too.  The US Centers for Disease Control recently posted a slightly tongue-in-cheek guide to preparing for a zombie apocalypse which outlines their approach to a large scale outbreak and gives good advice on general disaster preparation.  "If you're ready for a zombie apocalypse," they say, "you're ready for any emergency."  And that's official government advice for US citizens.

In the UK we tend to be a little more reserved in our Armageddon preparations, but zombies are starting to pop up on the radar.  After a freedom of information request Leicester City Council recently admitted that they are "unaware of any specific reference to a zombie attack in the council's emergency plan", a situation that will hopefully be rectified as a result of the publicity generated.

Political bodies aren't the only ones waking up to the very real usefulness of preparing for Z-day.  In 2009 the prestigious journal Infectious Disease Modelling Research Progress published a paper entitled "When Zombies Attack!: Mathematical Modelling Of An Outbreak Of Zombie Infection".  (Munz, Hudea, Imad & Smith).  This perfectly serious (if lighthearted) paper uses proper epidemiological methods to simulate the effects of an uprising and concludes that quarantine and cures do very little to help - swift and aggressive action is required if we're going to stand a chance.  The models used have also found real world applications which do not require the undead roaming the streets:

The key difference between the models presented here and other models of infectious disease is that the dead can come back to life. Clearly, this is an unlikely scenario if taken literally, but possible real-life applications may include allegiance to political parties, or diseases with a dormant infection.
- Munz et al (2009)
The Munz et al paper also holds the distinction of being the only peer reviewed work I've seen which references Bainov and Simeonov's Impulsive Differential Equations: Asymptotic Properties of the Solutions (1995) alongside Frost and Pegg's Shaun Of The Dead (2002).

So apart from disaster management, bio/political mathematical models and some very entertaining films and computer games, what have the undead ever done for us?  I've got one more idea up my sleeve...

There are some mathematical questions which are very difficult to solve, the travelling salesman problem being a classic example.  One way to find an answer quickly is called ant colony optimisation, it simulates the way ants find their way around to find what is probably the right answer (note the "probably" - it's not a proof, just a good estimate).  I firmly believe that software zombie simulants can be used to perform a variation on ant colony optimisation - in fact, if we had a real zombie uprising in a major city we could use careful placements of unprepared people (or "bait") to find optimal taxi routes.  And that's something that's useful to everybody.

Wednesday, 8 June 2011

How Plastic Bags Will Save The Planet

A couple of years ago a bandwagon started rolling through the UK.  Led by newspapers, and with the supermarkets and the government as the main passengers, a large proportion of the public jumped on board.  The target of this bandwagon was the humble plastic bag, provided for free by almost every shop in the country.

Plastic bags, you see, are evil.  They come from oil, and as we all know we should be using less of that.  Plus they choke turtles and strangle swans.

So shops started discouraging their use - customers were charged for them, asked if they really needed one, and offered bigger, tougher reusable bags.  But I think we've missed a trick here.

We need to look at what the evils actually are.  Let's take the turtles and swans for starters.  Plastic bags don't have to harm them.  I've got a bunch of them in the cupboard above the cooker and I've never discovered a dead swan in there.  It's not the bags themselves that cause the problem, it's their disposal.  Jamie, our venerable 16 year old Jack Russell once got into the Christmas chocolate and ended up with some serious kidney problems for his trouble, but that's not Cadbury's fault, it was ours for leaving it in his reach.  Wildlife deaths are a littering problem, not a plastic bag problem.

So is using oil an evil?  Well, this is where things get interesting.  You can do lots of things with oil:

  1. Leave it in the ground.
  2. Turn it into fuel and burn it.
  3. Turn it into plastics.
Option one is clearly the most environmentally friendly, but I think I can suggest that's a fairly unlikely outcome.  The second is probably the worst as far as things go - if the anthropogenic global warming theories are correct then this option is the one causing most of the problems.  That leaves the third option, turning it into plastics.

As we all know, plastic doesn't break down easily.  Hundreds of years is the number you'll hear bandied around - but what's wrong with that?  It means your supermarket carrier bag, if disposed of in landfill, will sit there for centuries, doing precisely nothing.  It won't break into carbon compounds and interfere with atmospheric chemistry, it will just be in the ground.  It's a very roundabout and inefficient way of doing option one, leaving the oil in the ground in the first place.  Plus, once oil becomes scarce enough, mining landfill for plastics will become profitable, and cheaper than drilling kilometres under the ocean for the raw material.

So we've got two reasonable options open to us: use the oil for fuel, or use it for plastics.  As far as I can see, the environmentally friendly option is to go for plastics.  Lots of them.  So many that when we run out of oil we've got something to show for it: plastic bags galore.  A little more atmospheric carbon is slightly less useful to the average person regardless of environmental effects, plastic mines on the other hand...well if you want to be cynical about it, there's money in plastic mines.

What about the people who need fuel, which is most of us?  Well, we're hideously bad at using it.  We burn oil in car engines, which are horribly inefficient, only around 20% of the energy in the fuel actually gets used for something practical (unless you regularly cook steak on your engine casing).  Burn it in a power station on the other hand, and you get around 33%.  Use that to charge fuel cells and you've got a bit more bang for your buck, and some leftover oil to turn into useful and environmentally friendly plastic bags.  In time, of course, we'll run out of oil and be forced to find alternatives - why shouldn't we be doing that sooner rather than later?  Use plastic bags and bring the future a little closer.

And plastic itself can be used for transport - paragliders for example, even small ones...