On the Equilibrium of Magic Stones

This paper considers the stone towers that have recently attracted attention at that, at first glance, seem impossible. It is shown that a body with three points of support (tripod) on an uneven surface, such as, in particular, an inclined plane, can serve as the base model of such a system. The necessary and sufficient equilibrium conditions are obtained of such towers. Estimates of the coefficient of friction for the supports that would ensure the equilibrium in case of ground vibration and wind are determined.