NewsPhysicsHula-hooping robots reveal the physics behind keeping rings aloftGyrating objects should be hourglass-shaped to hold a hoop steady Experiments with hula-hooping robots revealed how the hoops stay up, providing some tips for humans aiming to perfect their technique.Klaus Vedfelt/Getty ImagesBy Emily Conover10 seconds agoTo keep a Hula-Hoop aloft, it helps to be in shape literally.Experiments with gyrating, hoop-slinging robots have revealed how these spinning rings stay up despite the pull of gravity. Theshape of the robots body is a crucial factor, researchers report in the Jan. 7Proceedings of the National Academy of Sciences.The shape needs to have hips a slope that provides upward force to counteract gravity. And a waist curvature like an hourglass keeps the hoop from drifting up or down and sliding off.