Absolute rotation
![Figure 1: The interface of two immiscible liquids rotating around a vertical axis is an upward-opening circular paraboloid.](/Images/godic/202412/19/Parabola_shape_in_rotating_layers_of_fluid3537.jpg")
![Figure 2: Two spheres tied with a string and rotating at an angular rate ω. Because of the rotation, the string tying the spheres together is under tension.](/Images/godic/202412/19/Rotating_spheres3537.PNG")
![Figure 3: An ellipsoid](/Images/godic/202412/19/Elipsoid_zplostely3537.png")
In physics, the concept of absolute rotation—rotation independent of any external reference—is a topic of debate about relativity, cosmology, and the nature of physical laws. The question of whether absolute rotation is meaningful is independent of the issue of the existence of absolute time and space.