Scientists Discover Two Competing Memories in Matter

Penn State researchers found that a non-Brownian particle suspension can store two competing memories at once: stirring direction and later rocking strength.

Gentle rocking preserved both memories, while stronger rocking erased the directional memory.

At even higher rocking intensity, the suspension formed a new memory of the later motion.

The study, published in Physical Review Letters and highlighted as an editors’ suggestion, offers a simple testbed for responsive materials.