👉 In mathematics, a "sphere" is a 3-dimensional object that encloses all points in space. A sphere can be defined as a set of points that are at a fixed distance from each other, and it has no volume. However, spheres have a specific property that allows them to form a special type of geometric shape called an "unsphere". Unspheres are formed when the radius of a sphere is changed, and they are used in various mathematical models such as celestial mechanics and fluid