The gravitational field strength on the surface of the Earth is g=GM/r2. If the angular rotation of the Earth at the surface corresponds to a centripetal acc of the same magnitude as g, the object will not be able to stay on the ground. In other words , the object is now 'weightless'. This happens to astronauts in the International space station where they experience weightlessness. They are said to be in orbit. We on Earth are just rotating at a much smaller angular velocity than if one were orbiting. The advert to zero G flight is only an experience but not really without g.
