Friction without contact discovered as magnetic forces break a 300-year-old law

Researchers at the University of Konstanz have identified a completely new type of sliding friction. In this case, resistance to motion occurs without any physical contact, arising instead from the collective behavior of magnetic elements. Their findings show that friction does not always increase steadily with load, as described by Amontons' law -- one of the oldest and most widely accepted empirical laws in physics -- but can reach a clear peak when magnetic ordering inside the s...