Patterns found in laboratory spark insight into nature and society

Patterns found in laboratory spark insight into nature and society: Epstein says non-linear dynamics and exotic reactions like oscillating chemical reactions are quite rare in chemistry but very important in biology, because every living system is full of reactions in which concentrations increase and decrease, typically on a daily cycle. Unraveling this phenomenon in chemistry is offering insights into pattern formation in other systems, such as human and animal populations.
 To better understand diffusion, cross-diffusion and oscillatory chemical reactions, Epstein revisits a science demo popular with the elementary school set: The glass of water and drop of food coloring...
“Chemists and physicists have largely ignored cross-diffusion,” says Epstein. “When you study diffusion in an introductory chemistry or physics course, the standard treatment completely ignores the possibility that if there are two different chemicals present one might influence the diffusion of the other..."

“Instead of having blue molecules and red molecules, maybe you have populations of two different ethnic groups that either like to be near each other or prefer to avoid each other,” says Epstein. “This might affect population patterns in a city or region.”