The Eötvös effect refers to the phenomenon where the weight of an object changes depending on its motion through a gravitational field. Named after the Hungarian physicist Lóránd Eötvös, this effect is particularly noticeable in rotating systems, such as the Earth. As an object moves, its weight can appear to decrease due to the influence of centrifugal forces. This effect is significant in fields like geophysics and engineering, as it helps scientists understand variations in gravitational forces. By studying the Eötvös effect, researchers can gain insights into the Earth's structure and the distribution of mass within it.