Scientists find that “perfect” systems may be surprisingly fragile

Complex systems may work better when their parts are not perfectly alike. Northwestern physicists found that carefully balanced variation, or “disorder,” can make networks such as power grids, ecosystems, neurons, and materials more stable. Even random differences sometimes improved stability compared with completely uniform systems.

The discovery could help researchers design more resilient technologies and explain why natural systems are so rarely perfectly uniform. Scientists find that “perfect” systems may be surprisingly fragile. Scientists find that “perfect” systems may be surprisingly fragile Science News from research organizations Scientists find that “perfect” systems may be surprisingly fragile Scientists found that a surprising dose of disorder can make complex systems more stable, turning “imperfections” into a potential design advantage.

For years, researchers often worked from the assumption that networks should perform more reliably when their individual parts behave as similarly as possible. Real systems, however, rarely look that tidy. Power generators operate differently from one another, neurons vary in form and behavior, species occupy different roles in ecosystems, and the components inside engineered materials are not always perfectly uniform.

Physicists at Northwestern University now say those differences may sometimes be an advantage rather than a defect.