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Attack of the undead

The problem with zombies

If Zombies really existed we would have to fight back quickly and really hard to stop the destruction of the human race. The problem with Zombies is that if you are bitten, then you’ll turn into a zombie too. This would result in zombies soon outnumbering the human population. Thankfully though, zombies only exist in books, films, video games and in Cwmbran. That is, they only exist in people’s imagination! But there is some good news about zombies: scientists have studied zombie attacks so we know how to deal with them!

Zombie attack!

What's the difference between a zombie outbreak and a disease?

Zombies infect humans by biting them so that the person becomes a zombie and goes on to bite other people. The really nasty thing about zombies is that they don’t get better: once a zombie, always a zombie! So, zombieism could spread much faster than an infectious disease.

People carrying an infectious disease can fly all over the world before their symptoms can be spotted. So we end up with multiple outbreaks. This makes it very hard to deal with, as happened with the latest outbreak of swine flu. But then again, it’s unlikely that zombies would go on foreign holidays so we would only have to deal with one centre of outbreak.

But, if we did find a cure for zombieism, could the ex-zombies be re-infected or would they be immune? Could a zombie virus mutate like the flu virus?

The problem with models

Models are only representations of an idealised reality. Even Naomi Campbell is the fashion industry’s 'idea' of a perfect woman. Fashion designers use her to try out new ideas for clothes. Model aircraft are built by engineers to try out new ideas for aerodynamics. The people who designed the great cathedrals and castles of the past used small models to work out if their designs would fall down.

Supermodel Naomi Campbell

Today’s top models (Not Naomi!)

The most common type of model today is the mathematical model. It doesn’t exist at all in reality, but only in the minds of the computer programmers and the silicon chips of computers. The model is probably the most powerful idea in the whole of science.

The most powerful model in science

Probably the most powerful model in science is the atomic model. Even today no one has ever seen an atom: they are just too small. Even the largest atom is only about 500 Pico meters across (500 x 10-12m). Still, everyone knows that everything is made of atoms, right! Well, how?

The atomic model can be used to explain how chemistry works. Two pieces of hydrogen and one piece of oxygen go in; one piece of water comes out.

The atomic model

It can explain why materials expand when they are heated, why evaporation happens, why liquids freeze to become solids or why they boil to become gasses. But, it is still only a model. It is just a very powerful way of thinking about something we cannot see. We think of atoms as tiny hard balls that vibrate in solids and move around in liquids and gasses and sometimes stick together. The atomic model is so powerful that most people don’t even see it as a model.

It's cheaper than hiring a mountain climber!

Hypothermia

For example, if you want to work out how long a person would take to get hyperthermia (low-body temperature) we could take an arctic explorer, put them in a large fridge and stick a thermometer up their bum to see how long it takes for them to cool down.

By far the easiest (and least uncomfortable) way to do it would be to make a model of a person. As we are all about 70 per cent water, we can just use a big bag of water and it will behave like an arctic explorer. Of course this is much cheaper than Hiring Sir Ranulph Twisleton-Wykeham-Fiennes for the day! Besides, such experiments would never be approved!

Working out body temperature using models

You just heat up a bag of water to normal body temperature, 37C, and make sure the surface area is the same as a human, and you can do a surprisingly accurate experiment. This is how forensic pathologists work out the time of death of a recently-deceased murder victim. They take the body temperature and work out how long a body of that size would take to cool to that particular temperature. Even very simple models can be really useful.

These days a scientist would never build a real model like the water bag, but would construct a model inside a computer. All the thermal characteristics of water are so well known that a computer model would be more accurate and probably cheaper too!

Ultimate computer models

Flight simulator

Have you ever wondered how a test pilot can take a brand new £250 million airliner like the Airbus A380 and take it for a perfect maiden flight? The answer is that he has flown the aircraft for many hundreds of hours before ever sitting in the pilot’s seat. As soon as a modern aircraft is starting to be designed software engineers are working with aerodynamicists to produce a flight simulation that will mimic the characteristics of the airliner as closely as possible. Of course, being a test pilot is not all tea and buns. They will never quite know that the numbers are correct until the real thing leaves the runway!

In fact, a big part of a modern test pilot’s job is feeding information back to the software designers to get the flight simulation programme as near to perfect as possible. Today, a modern airline pilot will fly a flight simulator and can then jump straight into the cockpit of a plane full of passengers and fly! Amazing!

So what can we learn from Zombies?

An outbreak of zombieism would quite likely be fatal for humankind unless very aggressive anti-zombie tactics were used. Quarantining is a very good idea and could lead to eradication, but just like quarantining a disease, zombies are good at escaping! So in reality, it would not be very practical.

The best tactic seems to be to knock off the zombies as quickly as possible at the start of an attack!

This is a fairly way out model, but it does demonstrate how powerful models can be to get people thinking creatively about problems. Einstein was a master of the model. He won his Nobel Prize for developing a model for light that used particles instead of waves. It changed the course of history and led to all manner of inventions from the CCD camera to the electron microscope.

Models are powerful, learn to use them.

The big questions:

What is a Model?

How does science use models?

How many different types of models can you think of?

How do models help us think about problems and solve them?