In Star Trek, a quantum filament is a type of spatial anomaly which can be hundreds of meters long. They are very difficult to detect because they have almost no mass. If a filament came into direct contact with a starship, it would cause severe systems damage. Only when a filament was in close proximity of a ship could the on-board sensors detect it because of its subspace distortions and high-energy particles. The USS Enterprise-D ran into several quantum filaments in 2368 (stardate 45156.1) and suffered a major power loss. Several crewmembers were killed or injured and with the emergency bulkheads closed due to the isolation protocol, they were trapped in various parts of the ship. The Enterprise was also in danger of losing antimatter containment, but the crew managed to restore power before this could occur. (TNG: "Disaster")

In real astrophysics, there are a few phenomena which are called filaments. They are the largest known structures in the universe, thread-like structures with a typical length of 50 to 80 h-1 megaparsecs that form the boundaries between large voids in the universe. Filaments consist of gravitationally-bound galaxies; parts where a large number of galaxies are very close to each other are called superclusters. In 2006, scientists announced the discovery of three filaments aligned to form the largest structure known to humankind, composed of densely-packed galaxies and enormous blobs of gas known as Lyman alpha blobs.

There are also solar filaments - these are large feature extending outward from the Sun's surface, often in a loop configuration, comprising of cool plasma that appears darker than its background (due to the lower temperature of the plasma).

However, the phenomena that is perhaps closest to the Star Trek quantum filament is the plasma filament. More commonly called Birkeland currents, a plasma filament generally refers to any electric current in a space plasma, but more specifically when charged particles in the current follow magnetic field lines. They are caused by the movement of a plasma perpendicular to a magnetic field. These currents often show filamentary, or twisted "rope-like" magnetic structure. Many structures in the universe exhibiting filamentation are due to plasma filaments, such as the Earth's Aurora, Venus Flux ropes, Cometary tails, the Sun's coronal streamers and various nebulae.

The novelty plasma lamp is a simple illustration of filamentation. The colors and patterns in a plasma lamp are a result of relaxation of electrons in excited states to lower energy states after they have recombined with ions. These processes emit light in a spectrum characteristic of the gas being excited.