Hopping

Hopping is a form of locomotion in which a person or animal moves by pushing off the ground with one or both feet, generating a sequence of short aerial moves. It is used by humans in athletic drills and dances, and by many animals, including rabbits and rodents that hop on their hind legs and larger marsupials such as kangaroos that rely on strong hind limbs and a balancing tail.

In biomechanics, hopping differs from jumping and leaping in its rhythm and ground contact pattern. It can involve alternating feet or single-foot contacts, with varying speed and height. In animals such as kangaroos, hopping is an efficient locomotion mode, aided by elastic energy storage in tendons and a brief stance phase that reduces muscular work per distance traveled.

Frequency hopping is a method in wireless communications where a signal rapidly changes carrier frequency according to a predefined sequence. This spread-spectrum technique, used in systems such as Bluetooth Classic and some military radio networks, helps reduce interference and eavesdropping and can improve resilience in crowded radio environments.

In brewing, hopping refers to the addition of hops to beer to impart bitterness, aroma, and flavor. Hops are the flowers of Humulus lupulus. The timing of hop additions—early for bittering, late for aroma, or during fermentation in dry hopping—shapes the beer’s profile and stability.