When the sphere passes through the plane of Flatland to show how he can move in three dimensions, the square sees only that the line he'd been observing gets shorter and shorter and then disappears.

A ring or sphere could, apparently, be stable if surrounded by the right sizes and gravities of other stars.

The owners behind the $2.3 billion Las Vegas Sphere are planning on creating smaller 'mini-Spheres' that would be able to seat 5,000 people.