Saturday, October 3, 2009 Physics of the Dead

If your ZSP involved heading towards the mall, Science! has just validated your decision. From LiveScience via io9:

The Best Approach for Avoiding Zombies

By Mike Lucibella, Inside Science News Service
posted: 28 September 2009 05:29 pm ET

WASHINGTON -- When Woody Harrelson escapes the living dead in "Zombieland", a new movie opening this Friday, should he head for the hills or the mall? A recently published research paper suggests that he's probably better off hiding in the mall to save his delicious brain.

The world is full of things that move in zombie-like fashion, such as particles flowing through a turbulent fluid or the unpredictable price changes of the stock market, so physicists seek insight into this behavior by creating so called "random walking" models.

Physicist Davide Cassi at the Università di Parma in Italy looked at how long an entity hiding in a complex structure could survive if being pursued by predatory random walkers. Cassi's paper, recently published in the journal Physical Review E, is the first to describe a general principle of a prey’s likelihood to survive over time while hiding in an irregular structure.

Though the paper itself does not specifically refer to fleeing from zombies, it describes "the survival probability of immobile targets annihilated by random walkers." The conclusions suggest that the people trapped in a mall in "Dawn of the Dead" may be better off than the folks stuck in a farmhouse in "Night of the Living Dead."

Cassi found that the likelihood of survival when threatened by predatory random walkers is closely related to how complex the prey’s hideout is. The more twists and turns, the safer you'll be. In structures that are highly complex and irregular, the chances of the predator coming into contact with its target shrinks down to almost zero.

Cassi formulates a model to describe the behavior of randomly moving particles as they travel through maze-like networks. He said that his work could apply to a wide variety of situations including the distribution of information through the internet and medicine spreading through the human body.

"There are a lot of applications of these results in a lot of fields of sciences," Cassi said. "The most amazing field of applications of these results are in biology, biochemistry and other organisms."

So remember, when the zombies come, flee to the biggest shopping mall you can find and remember that, using zombie movies as a guide, the undead often win.

Extrapolating the findings in the paper to a zombie shopping mall scenario is a little suspect (and probably wouldn't have happened if a certain major studio picture wasn't premiering this weekend). For starters, we aren't talking about a few "random walkers" but a potential horde of predators. And the model seems to predicate that the prey is actively avoiding its hunter and not just chilling in the food court between rounds of Wii Golf. Most importantly, the model also maps the difficulty one would have tracking down any lingering zeds missed during the initial sweep of an infested mall. Which means if anything, it reveals that such an environment is much less safe than we might have thought.

It's okay, though, as we covet the post-apocalyptic mall not for the dubious protection of a maze-like interior, but for the promise of luxury goods, ample living space, and copious amenities. Which once again proves that the survivors in the Dawn of the Dead remake were prize chumps. "Yeah, it sucks staying here in comfort and safety. Let's try to fight our way through thousands of hyper, unstoppable cannibals and make for some unknown place where we'll likely starve or freeze if we don't get et first." Assholes.