Wormhole interior. Conceptual computer illustration of the interior of a tunnel, representing a wormhole. Wormholes are a possible solution to Einstein's equations that describe the properties of space-time, the continuum of unified space and time. Theorists have suggested that on the smallest scale of the universe (the incredibly small Planck length), the fabric of space-time may be riddled with these tunnel-like wormholes. The concept is also found in science fiction, where they are used to travel between distant points of the universe. However, as wormholes would last for less than a second, such use would probably be impossible.