Why does a gyroscope resist changes in orientation?

A fast-spinning gyroscope has significant angular momentum, which means it strongly resists changes to the direction of its spin axis. If you try to tilt it, the applied torque does not simply make it fall; instead, it causes the axis to move sideways in precession. This behavior follows directly from conservation of angular momentum, a core principle of physics. Gyroscopes are used in navigation systems, phones, and spacecraft because they help measure rotation and maintain orientation. Early practical gyroscopes were developed in the 19th century, notably by Léon Foucault in the 1850s.