Supplee’s Paradox

Supplee’s Paradox is about whether a relativistic projectile, subject to uniform gravitational acceleration, would float or sink underwater. It arises when considering the buoyant force exerted on a relativistic bullet immersed in a fluid subject to an ambient gravitational field. It has also been studied by George Matsas, who used mathematical methods from general relativity to remove Supplee’s assumptions. In particular, he modeled the situation using a Rindler chart.