A black hole is a region of spacetime where gravity is so strong that nothing, not even light and other electromagnetic waves, is capable of possessing enough energy to escape it. Einstein's theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary of no escape is called the event horizon. A black hole has a great effect on the fate and circumstances of an object crossing it, but it has no locally detectable features according to general relativity. In many ways, a black hole acts like an ideal black body, as it reflects no light. Quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is of the order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly.
General relativity, also known as the general theory of relativity, and as Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime. In particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of second order partial differential equations.
In general relativity, a naked singularity is a hypothetical gravitational singularity without an event horizon.
Singularity or singular point may refer to:
A wormhole is a hypothetical structure connecting disparate points in spacetime, and is based on a special solution of the Einstein field equations.
The Alcubierre drive is a speculative warp drive idea according to which a spacecraft could achieve apparent faster-than-light travel by contracting space in front of it and expanding space behind it, under the assumption that a configurable energy-density field lower than that of vacuum could be created. Proposed by theoretical physicist Miguel Alcubierre in 1994, the Alcubierre drive is based on a solution of Einstein's field equations. Since those solutions are metric tensors, the Alcubierre drive is also referred to as Alcubierre metric.
The Star Trek fictional universe contains a variety of weapons, ranging from missiles to melee. The Star Trek franchise consists mainly of several multi-season television shows and a dozen movies, as well as various video games and inspired merchandise. Many aspects of the Star Trek universe impact modern popular culture, especially its fictitious terminology and the concept of weaponry on spacecraft. The franchise has had a widespread influence on its audiences from the late 20th to early 21st century. Notably, Star Trek's science fiction concepts have been studied by real scientists; NASA described it in relation to the real world as "entertaining combination of real science, imaginary science gathered from lots of earlier stories, and stuff the writers make up week-by-week to give each new episode novelty." For example, NASA noted that the Star Trek "phasers" were a fictional extrapolation of real-life lasers, and compared them to real-life microwave based weapons that have a stunning effect.
A gravitational singularity, spacetime singularity or simply singularity is a condition in which gravity is predicted to be so intense that spacetime itself would break down catastrophically. As such, a singularity is by definition no longer part of the regular spacetime and cannot be determined by "where" or "when". Gravitational singularities exist at a junction between general relativity and quantum mechanics; therefore, the properties of the singularity cannot be described without an established theory of quantum gravity. Trying to find a complete and precise definition of singularities in the theory of general relativity, the current best theory of gravity, remains a difficult problem. A singularity in general relativity can be defined by the scalar invariant curvature becoming infinite or, better, by a geodesic being incomplete.
A warp drive or a drive enabling space warp is a fictional superluminal spacecraft propulsion system in many science fiction works, most notably Star Trek, and a subject of ongoing physics research. The general concept of "warp drive" was introduced by John W. Campbell in his 1957 novel Islands of Space and was popularized by the Star Trek series. Its closest real-life equivalent is the Alcubierre drive, a theoretical solution of the field equations of general relativity.
In general relativity, a white hole is a hypothetical region of spacetime and singularity that cannot be entered from the outside, although energy-matter, light and information can escape from it. In this sense, it is the reverse of a black hole, from which energy-matter, light and information cannot escape. White holes appear in the theory of eternal black holes. In addition to a black hole region in the future, such a solution of the Einstein field equations has a white hole region in its past. This region does not exist for black holes that have formed through gravitational collapse, however, nor are there any observed physical processes through which a white hole could be formed.
A Stargate is a fictional Einstein–Rosen bridge portal device within the Stargate fictional universe that allows practical, rapid travel between two distant locations. The devices first appeared in the 1994 Roland Emmerich film Stargate, and thereafter in the television series Stargate SG-1, Stargate Infinity, Stargate Atlantis, Stargate Universe, and Stargate Origins. In these productions, the Stargate functions as a plot device, allowing the main characters to visit alien planets without the need for spaceships or any other type of technology. The device allows for near-instantaneous teleportation across both interstellar and extragalactic distances.
General relativity is a theory of gravitation developed by Albert Einstein between 1907 and 1915. The theory of general relativity says that the observed gravitational effect between masses results from their warping of spacetime.
Fuzzballs are hypothetical objects in superstring theory, intended to provide a fully quantum description of the black holes predicted by general relativity.
Black Holes & Time Warps: Einstein's Outrageous Legacy is a 1994 popular science book by physicist Kip Thorne. It provides an illustrated overview of the history and development of black hole theory, from its roots in Newtonian mechanics until the early 1990s.
"Parallax" is the third episode of the science fiction television series Star Trek: Voyager. The episode was directed by Kim Friedman and broadcast on January 23, 1995. The story was written by Jim Trombetta with the teleplay by Brannon Braga.
A wormhole is a postulated method, within the general theory of relativity, of moving from one point in space to another without crossing the space between. Wormholes are a popular feature of science fiction as they allow faster-than-light interstellar travel within human timescales.
"Hunters" is the 83rd episode of the science fiction television series Star Trek: Voyager, the 15th episode of the fourth season, and the first episode of the Hirogen story arc. The series is about a spaceship returning to Earth, after being flung to the other side of the Galaxy, and is set in the 24th century of the Star Trek science fiction universe.
The following outline is provided as an overview of and topical guide to black holes:
