The Best Approach for Avoiding Zombies

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.

Inside Science News Service is supported by the American Institute of Physics.