Analogy to a wormhole in a curved 2D space (see Embedding Diagram)

Artist's impression of a wormhole as seen by an observer crossing the event horizon of a Schwarzschild wormhole, which is similar to a Schwarzschild black hole but with the singularity replaced by an unstable path to a white hole in another universe. The observer originates from the right, and another universe becomes visible in the center of the wormhole shadow once the horizon is crossed. This new region is, however, unreachable in the case of a Schwarzschild wormhole, as the bridge between the black hole and white hole will always collapse before the observer has time to cross it. See White Holes and Wormholes for a more technical discussion and an animation of what an observer sees when falling into a Schwarzschild wormhole.

In physics, a wormhole is a hypothetical topological feature of spacetime that is basically a 'shortcut' through space and time. A wormhole has at least two mouths which are connected to a single throat or tube. If the wormhole is traversable, matter can 'travel' from one mouth to the other by passing through the throat. While there is no observational evidence for wormholes, spacetimes containing wormholes are known to be valid solutions in general relativity. Wormhole may refer to: Media Bajoran wormhole, wormhole located near the planet Bajor in the fictional Star Trek universe Wormholes - Essays and Occasional Writings, book containing writings from four decades by the English author John Fowles Wormhole X-Treme!, fictional television program shown inside the Stargate SG-1 episode Wormhole... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Image File history File links Download high resolution version (2560x2048, 4704 KB) Summary View of a Schwarzschild wormhole as would be seen by a free falling observer on a Schwarschild black hole. ... Image File history File links Download high resolution version (2560x2048, 4704 KB) Summary View of a Schwarzschild wormhole as would be seen by a free falling observer on a Schwarschild black hole. ... For the science fiction film, see Event Horizon (film). ... For other uses, see Wormhole (disambiguation). ... A Schwarzschild black hole or static black hole is a black hole fully defined by its only parameter, the mass M. In general black holes could have in addition angular momentum (rotating black holes) and electric charge (see charged black holes). ... For the Red Dwarf episode, see White Hole (Red Dwarf episode). ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... A Möbius strip, an object with only one surface and one edge; such shapes are an object of study in topology. ... For other uses of this term, see Spacetime (disambiguation). ... This article is about the idea of space. ... This article is about the concept of time. ... This article is about matter in physics and chemistry. ... For a less technical and generally accessible introduction to the topic, see Introduction to general relativity. ...

The term wormhole was coined by the American theoretical physicist John Wheeler in 1957. However, the idea of wormholes was invented already in 1921 by the German mathematician Hermann Weyl in connection with his analysis of mass in terms of electromagnetic field energy.^[1] Theoretical physics attempts to understand the world by making a model of reality, used for rationalizing, explaining, predicting physical phenomena through a physical theory. There are three types of theories in physics; mainstream theories, proposed theories and fringe theories. ... John Archibald Wheeler (born July 9, 1911) is an eminent American theoretical physicist. ... Hermann Klaus Hugo Weyl (November 9, 1885 – December 9, 1955) was a German mathematician. ... The electromagnetic field is a physical field that is produced by electrically charged objects and which affects the behaviour of charged objects in the vicinity of the field. ...

This analysis forces one to consider situations...where there is a net flux of lines of force through what topologists would call a handle of the multiply-connected space and what physicists might perhaps be excused for more vividly terming a ‘wormhole’.

– John Wheeler in Annals of Physics

The name "wormhole" comes from an analogy used to explain the phenomenon. If a worm is travelling over the skin of an apple, then the worm could take a shortcut to the opposite side of the apple's skin by burrowing through its center, rather than travelling the entire distance around, just as a wormhole traveler could take a shortcut to the opposite side of the universe through a topologically nontrivial tunnel. Species Malus domestica Malus sieversii Apple is the fruit (pome) of the genus Malus belonging to the family Rosaceae, and is one of the most widely cultivated tree fruits. ... For other uses, see Universe (disambiguation). ...

Definition

The basic notion of an intra-universe wormhole is that it is a compact region of spacetime whose boundary is topologically trivial but whose interior is not simply connected. Formalizing this idea leads to definitions such as the following, taken from Matt Visser's Lorentzian Wormholes: In mathematics, a subset of Euclidean space Rn is called compact if it is closed and bounded. ... For other uses of this term, see Spacetime (disambiguation). ... A geometrical object is called simply connected if it consists of one piece and doesnt have any circle-shaped holes or handles. Higher-dimensional holes are allowed. ...

If a Lorentzian spacetime contains a compact region Ω, and if the topology of Ω is of the form Ω ~ R x Σ, where Σ is a three-manifold of nontrivial topology, whose boundary has topology of the form dΣ ~ S², and if, furthermore, the hypersurfaces Σ are all spacelike, then the region Ω contains a quasipermanent intra-universe wormhole.

Characterizing inter-universe wormholes is more difficult. For example, one can imagine a 'baby' universe connected to its 'parent' by a narrow 'umbilicus'. One might like to regard the umbilicus as the throat of a wormhole, but the space time is simply connected. For other uses of this term, see Spacetime (disambiguation). ...

Wormhole types

Intra-universe wormholes connect one location of a universe to another location of the same universe (in the same present time or unpresent). A wormhole should be able to connect distant locations in the universe by creating a shortcut through spacetime, allowing travel between them that is faster than it would take light to make the journey through normal space. See the image above. Inter-universe wormholes connect one universe with another [1], [2]. This gives rise to the speculation that such wormholes could be used to travel from one parallel universe to another. A wormhole which connects (usually closed) universes is often called a Schwarzschild wormhole. Another application of a wormhole might be time travel. In that case, it is a shortcut from one point in space and time to another. In string theory, a wormhole has been envisioned to connect two D-branes, where the mouths are attached to the branes and are connected by a flux tube [3]. Finally, wormholes are believed to be a part of spacetime foam [4]. There are two main types of wormholes: Lorentzian wormholes and Euclidean wormholes. Lorentzian wormholes are mainly studied in general relativity and semiclassical gravity, while Euclidean wormholes are studied in particle physics. Traversable wormholes are a special kind of Lorentzian wormholes which would allow a human to travel from one side of the wormhole to the other. Serguei Krasnikov suggested the term spacetime shortcut as a more general term for (traversable) wormholes and propulsion systems like the Alcubierre drive and the Krasnikov tube to indicate hyperfast interstellar travel. For other uses of this term, see Spacetime (disambiguation). ... The many-worlds interpretation or MWI (also known as relative state formulation, theory of the universal wavefunction, many-universes interpretation, Oxford interpretation or many worlds), is an interpretation of quantum mechanics that claims to resolve all the paradoxes of quantum theory by allowing every possible outcome to every event to... A closed universe is a universe in which there is enough internal mass to warp the boundary of the universe until becomes totally curved - nothing can exit through the universes boundary, it has effectively sealed itself. ... For other uses, see Wormhole (disambiguation). ... Time travel is a concept that has long fascinated humanity—whether it is Merlin experiencing time backwards, or religious traditions like Mohammeds trip to Jerusalem and ascent to heaven, returning before a glass knocked over had spilt its contents. ... Interaction in the subatomic world: world lines of pointlike particles in the Standard Model or a world sheet swept up by closed strings in string theory This box:      String theory is a model of fundamental physics, whose building blocks are one-dimensional extended objects called strings, rather than the zero... In theoretical physics, D-branes are a special class of p-branes, named for the mathematician Johann Dirichlet. ... Flux tubes are strong porportions of magnetic fields shaped like tubes, usually surrounding large cosmic bodies such as stars. ... John Wheeler derived the concept of the quantum foam in 1955. ... For a less technical and generally accessible introduction to the topic, see Introduction to general relativity. ... Semiclassical gravity is the approximation to the theory of quantum gravity in which one treats matter fields as being quantum and the gravitational field as being classical. ... Thousands of particles explode from the collision point of two relativistic (100 GeV per nucleon) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ... For other uses, see Wormhole (disambiguation). ... Serguei Vladilenovich Krasnikov (Сергей Владиленович Красников), (1961) is a Russian physicist holding a Ph. ... A remote camera captures a close-up view of a Space Shuttle Main Engine during a test firing at the John C. Stennis Space Center in Hancock County, Mississippi Spacecraft propulsion is any method used to change the velocity of spacecraft and artificial satellites. ... This article is about the Alcubierre metric. ... The Krasnikov Tube is a theoretical mechanism for space travel involving the permanent warping of spacetime into superluminal tunnels. ...

Theoretical basis

It is known that (Lorentzian) wormholes are not excluded within the framework of general relativity, but the physical plausibility of these solutions is uncertain. It is also unknown whether a theory of quantum gravity, merging general relativity with quantum mechanics, would still allow them. Most known solutions of general relativity which allow for traversable wormholes require the existence of exotic matter, a theoretical substance which has negative energy density. However, it has not been mathematically proven that this is an absolute requirement for traversable wormholes, nor has it been established that exotic matter cannot exist. For a less technical and generally accessible introduction to the topic, see Introduction to general relativity. ... Quantum gravity is the field of theoretical physics attempting to unify quantum mechanics, which describes three of the fundamental forces of nature, with general relativity, the theory of the fourth fundamental force: gravity. ... For a generally accessible and less technical introduction to the topic, see Introduction to quantum mechanics. ... Exotic matter is a hypothetical concept of particle physics. ... Energy density is the amount of energy stored in a given system or region of space per unit volume, or per unit mass, depending on the context. ...

In March 2005, Amos Ori envisioned a wormhole which allows time travel, does not require any exotic matter and satisfies the weak, dominant, and strong energy conditions [5]. The stability of this solution is uncertain, so it is unclear whether infinite precision would be required for it to form in a way that allows time travel and also whether quantum effects would uphold chronology protection in this case, as analyses using semiclassical gravity have suggested they might do in the case of traversable wormholes. Amos Ori is a professor of Physics at the Technion Israel Institute of Technology in Haifa, Israel. ... In relativistic classical field theories of gravitation, particularly general relativity, an energy condition is one of various alternative conditions which are not consequences of the field equation but which can be imposed on a spacetime model as an additional constraint. ... The chronology protection conjecture is a conjecture by the physicist Professor Stephen Hawking that the laws of physics are such as to prevent time travel (closed timelike curves) on all but sub-microscopic scales. ... Semiclassical gravity is the approximation to the theory of quantum gravity in which one treats matter fields as being quantum and the gravitational field as being classical. ...

Schwarzschild wormholes

Embedded diagram of a Schwarzschild wormhole.

Lorentzian wormholes known as Schwarzschild wormholes or Einstein-Rosen bridges are bridges between areas of space that can be modeled as vacuum solutions to the Einstein field equations by combining models of a black hole and a white hole. This solution was discovered by Albert Einstein and his colleague Nathan Rosen, who first published the result in 1935. However, in 1962 John A. Wheeler and Robert W. Fuller published a paper showing that this type of wormhole is unstable, and that it will pinch off instantly as soon as it forms, preventing even light from making it through. A vacuum solution is a solution of a field equation in which the sources of the field are taken to be identically zero. ... The Einstein field equations (EFE) or Einsteins equations are a set of ten equations in Einsteins theory of general relativity in which the fundamental force of gravitation is described as a curved spacetime caused by matter and energy. ... For other uses, see Black hole (disambiguation). ... For the Red Dwarf episode, see White Hole (Red Dwarf episode). ... “Einstein” redirects here. ... Nathan Rosen (March 22, 1909 – December 18, 1995) was a physicist. ... John Archibald Wheeler (born July 9, 1911) is an eminent American theoretical physicist. ... Robert W. Fuller earned his Ph. ...

Before the stability problems of Schwarzschild wormholes were apparent, it was proposed that quasars were white holes forming the ends of wormholes of this type. The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...

While Schwarzschild wormholes are not traversable, their existence inspired Kip Thorne to imagine traversable wormholes created by holding the 'throat' of a Schwarzschild wormhole open with exotic matter (material that has negative mass/energy).
Kip S. Thorne Professor Kip Stephen Thorne, Ph. ... Exotic matter is a hypothetical concept of particle physics. ...

Traversable wormholes

Lorentzian traversable wormholes would allow travel from one part of the universe to another part of that same universe very quickly or would allow travel from one universe to another. The possibility of traversable wormholes in general relativity was first demonstrated by Kip Thorne and his graduate student Mike Morris in a 1988 paper; for this reason, the type of traversable wormhole they proposed, held open by a spherical shell of exotic matter, is referred to as a Morris-Thorne wormhole. Later, other types of traversable wormholes were discovered as allowable solutions to the equations of general relativity, including a variety analyzed in a 1989 paper by Matt Visser, in which a path through the wormhole can be made in which the traversing path does not pass through a region of exotic matter. A type held open by negative mass cosmic strings was put forth by Visser in collaboration with Cramer et al.,^[2], in which it was proposed that such wormholes could have been naturally created in the early universe. Kip S. Thorne Professor Kip Stephen Thorne, Ph. ... Mike Morris, a. ... Exotic matter is a hypothetical concept of particle physics. ... Professor Matt Visser is a Mathematics Professor at Victoria University of Wellington. ... A cosmic string is a hypothetical 1-dimensional topological defect in the fabric of spacetime. ... John G. Cramer (born 1934) is a Professor of Physics at the University of Washington in Seattle, USA. When not teaching, he works with the STAR detector at the new Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, and the particle accelerator at CERN in Geneva, Switzerland. ...

Wormholes connect two points in spacetime, which means that they would in principle allow travel in time as well as in space. In a 1988 paper, Morris, Thorne and Yurtsever^[3] worked out explicitly how to convert a wormhole traversing space into one traversing time. For other uses of this term, see Spacetime (disambiguation). ... Time travel is a concept that has long fascinated humanity—whether it is Merlin experiencing time backwards, or religious traditions like Mohammeds trip to Jerusalem and ascent to heaven, returning before a glass knocked over had spilt its contents. ...

Wormholes and faster-than-light travel

Special relativity only applies locally. Wormholes allow superluminal (faster-than-light) travel by ensuring that the speed of light is not exceeded locally at any time. While traveling through a wormhole, subluminal (slower-than-light) speeds are used. If two points are connected by a wormhole, the time taken to traverse it would be less than the time it would take a light beam to make the journey if it took a path through the space outside the wormhole. However, a light beam traveling through the wormhole would always beat the traveler. As an analogy, running around to the opposite side of a mountain at maximum speed may take longer than walking through a tunnel crossing it. You can walk slowly while reaching your destination more quickly because the length of your path is shorter. This article is about the principle of locality in physics. ... Faster-than-light (also superluminal or FTL) communications and travel are staples of the science fiction genre. ...

Wormholes and time travel

A wormhole could allow time travel.^[3] This could be accomplished by accelerating one end of the wormhole to a high velocity relative to the other, and then sometime later bringing it back; relativistic time dilation would result in the accelerated wormhole mouth aging less than the stationary one as seen by an external observer, similar to what is seen in the twin paradox. However, time connects differently through the wormhole than outside it, so that synchronized clocks at each mouth will remain synchronized to someone traveling through the wormhole itself, no matter how the mouths move around. This means that anything which entered the accelerated wormhole mouth would exit the stationary one at a point in time prior to its entry. For example, if clocks at both mouths both showed the date as 2000 before one mouth was accelerated, and after being taken on a trip at relativistic velocities the accelerated mouth was brought back to the same region as the stationary mouth with the accelerated mouth's clock reading 2005 while the stationary mouth's clock read 2010, then a traveler who entered the accelerated mouth at this moment would exit the stationary mouth when its clock also read 2005, in the same region but now five years in the past. Such a configuration of wormholes would allow for a particle's world line to form a closed loop in spacetime, known as a closed timelike curve. Time travel is a concept that has long fascinated humanity—whether it is Merlin experiencing time backwards, or religious traditions like Mohammeds trip to Jerusalem and ascent to heaven, returning before a glass knocked over had spilt its contents. ... For a less technical and generally accessible introduction to the topic, see Introduction to special relativity. ... Time dilation is the phenomenon whereby an observer finds that anothers clock which is physically identical to their own is ticking at a slower rate as measured by their own clock. ... In physics, the twin paradox refers to a thought experiment in Special Relativity, in which a person who makes a journey into space in a high-speed rocket will return home to find they have aged less than an identical twin who stayed on Earth. ... In physics, the world line of an object is the unique path of that object as it travels through 4-dimensional spacetime. ... In a Lorentzian manifold, a closed timelike curve (CTC) is a worldline of a material particle in spacetime that is closed. ...

It is thought that it may not be possible to convert a wormhole into a time machine in this manner: some analyses using the semiclassical approach to incorporating quantum effects into general relativity indicate that a feedback loop of virtual particles would circulate through the wormhole with ever-increasing intensity, destroying it before any information could be passed through it, in keeping with the chronology protection conjecture. This has been called into question by the suggestion that radiation would disperse after traveling through the wormhole, therefore preventing infinite accumulation. The debate on this matter is described by Kip S. Thorne in the book Black Holes and Time Warps. There is also the Roman ring, which is a configuration of more than one wormhole. This ring seems to allow a closed time loop with stable wormholes when analyzed using semiclassical gravity, although without a full theory of quantum gravity it is uncertain whether the semiclassical approach is reliable in this case. Semiclassical gravity is the approximation to the theory of quantum gravity in which one treats matter fields as being quantum and the gravitational field as being classical. ... In physics, a virtual particle is a particle which exists for such a short time and space that its energy and momentum do not have to obey the usual relationship. ... The chronology protection conjecture is a conjecture by the physicist Professor Stephen Hawking that the laws of physics are such as to prevent time travel (closed timelike curves) on all but sub-microscopic scales. ... Kip S. Thorne Professor Kip Stephen Thorne, Ph. ... This page is a candidate for speedy deletion. ... A Roman ring, in theoretical physics, is a type of wormhole where the time difference across its mouths is such that it may not allow a closed timelike curve (CTC), or closed-time loop. If these wormholes and their mouths are arranged in a suitable configuration, a closed time loop... Quantum gravity is the field of theoretical physics attempting to unify quantum mechanics, which describes three of the fundamental forces of nature, with general relativity, the theory of the fourth fundamental force: gravity. ...

Wormhole metrics

Theories of wormhole metrics describe the spacetime geometry of a wormhole and serve as theoretical models for time travel. An example of a (traversable) wormhole metric is the following: In mathematics, in Riemannian geometry, the metric tensor is a tensor of rank 2 that is used to measure distance and angle in a space. ...

One type of non-traversable wormhole metric is the Schwarzschild solution: In mathematics, in Riemannian geometry, the metric tensor is a tensor of rank 2 that is used to measure distance and angle in a space. ... Introduction In Einsteins theory of general relativity, the Schwarzschild metric is the most general static, spherically symmetric solution of the vacuum field equations. ...

Wormholes in fiction

Main article: Wormholes in fiction

Wormholes are a popular feature of science fiction as they allow interstellar (and sometimes interuniversal) travel within human timescales. It is common for the creators of a fictional universe to decide that faster-than-light travel is either impossible or that the technology does not yet exist, but to use wormholes as a means of allowing humans to travel long distances in short periods. Military science fiction (such as the Wing Commander games) often use a "jump drive" to propel a spacecraft between two fixed "jump points" connecting stellar systems. Connecting systems in a network like this results in a fixed "terrain" with choke points that can be useful for constructing plots related to military campaigns. The Alderson points used by Larry Niven and Jerry Pournelle in The Mote in God's Eye and related novels are an example, although the mechanism does not seem to describe actual wormhole physics. David Weber has also used the device in the Honorverse and other books such as those based upon the Starfire universe. Naturally occurring wormholes form the basis for interstellar travel in Lois McMaster Bujold's Vorkosigan Saga. They are also used to create an Interstellar Commonwealth in Peter F. Hamilton's Commonwealth Saga. Wormholes are a postulated method, within the general theory of relativity, of moving from one point in space to another without crossing the space between. ... Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Faster-than-light (also superluminal or FTL) communications and travel are staples of the science fiction genre. ... Wing Commander I title screen Wing Commander is a media franchise consisting of space combat simulation computer games from Origin Systems, Inc. ... This article does not cite any references or sources. ... Jerry Eugene Pournelle, Ph. ... The Mote in Gods Eye, by Larry Niven and Jerry Pournelle, is a science fiction novel that was first published in 1974. ... Honor Harrington from Honor Among Enemies cover, by David Mattingly. ... Map of the Honorverse. ... STARFIRE is a 4X board game (eXplore, eXpand, eXploit and eXterminate) of space warfare in the 23rd century, created by Stephen V. Cole in 1976. ... Lois McMaster Bujold (November 2, 1949, Columbus, Ohio) is an American author of science fiction and fantasy works. ... The Vorkosigan Saga is a series of science fiction novels and short stories by Lois McMaster Bujold, most of which concern Miles Vorkosigan, a disabled aristocrat from the planet Barrayar who heads his own private mercenary fleet at the age of just seventeen. ... Peter F. Hamilton Peter F. Hamilton Peter F. Hamilton (born 1960, Rutland, England), is a British science fiction author. ... The Commonwealth Saga is a series of science fiction novels by British science fiction writer Peter F. Hamilton. ...

Wormholes also play pivotal roles in science fiction where faster-than-light travel is possible though limited, allowing connections between regions that would be otherwise unreachable within conventional timelines. Several examples appear in the Star Trek franchise, including the Bajoran wormhole in the Deep Space Nine series. This article is about the entire Star Trek franchise. ... In the fictional Star Trek universe, the Bajoran wormhole is a wormhole located near the planet Bajor. ... Space station Star Trek: Deep Space Nine (ST:DS9 or STDS9 or DS9 for short) is a science fiction television series produced by Paramount and set in the Star Trek universe. ...

In Carl Sagan's novel Contact and subsequent 1997 film starring Jodie Foster and Matthew McConaughey, Foster's character Ellie travels 26 light years through a series of wormholes to the star Vega. The round trip, which to Ellie lasts 18 hours, passes by in a fraction of a second on Earth, making it seem that she didn't go anywhere. In her defense, Foster mentions an Einstein-Rosen bridge and tells how she was able to travel faster than light and time. Analysis of the situation by Kip Thorne, on the request of Sagan, is quoted by Thorne as being his original impetus for analyzing the physics of wormholes. Contact is a science fiction novel written by Carl Sagan and published in 1985. ... Contact is a 1997 science fiction film adapted from the novel by Carl Sagan. ... Alicia Christian Jodie Foster (born November 19, 1962)[1] is a two-time Academy Award-winning American actress, director and producer. ... Matthew David McConaughey (born November 4, 1969) is an American actor. ... For other uses, see Vega (disambiguation). ...

Wormholes play major roles in the television series Farscape, where they are the cause of John Crichton's presence in the alien universe, and in the Stargate series, where stargates create a stable artificial wormhole where matter is disintegrated, converted into energy, and is sent through to be reintegrated at the other side. In the science fiction series Sliders, a wormhole (or vortex, as it is usually called in the show) is used to travel between parallel worlds, and one is seen at least once or twice in every episode. In the pilot episode it was referred to as an "Einstein-Rosen-Podolsky bridge". Wormholes are part of the main back-story in the MMORPG EVE Online. Farscape (1999–2003) is a science fiction television series, featuring a present-day astronaut who accidentally travels through a wormhole to a distant part of the galaxy. ... An activated Stargate, the central object of the fictional Stargate universe, here depicted in the SG-1 television series. ... For other possible meanings, see Slider (disambiguation). ... EVE Online is a persistent world multiplayer online game set in space. ...

The central theme in the movie Donnie Darko revolves around Einstein-Rosen bridges. For the fictional character, see Donald Darko. ...

See also

• Black hole
  • Supermassive black hole
  • Micro black hole
  • Intermediate-mass black hole
  • Rotating black hole
• White hole
• Gravastar
• Compact stars
• Faster-than-light
• Chronology protection conjecture
• Alcubierre drive
• Neutron star
• Self-consistency principle
• Roman ring
• Schwarzschild metric
• Schwarzschild radius
• String theory
• Theory of relativity
• Time travel
• Timeline of black hole physics
• Spacecraft propulsion
• Krasnikov Tube

For other uses, see Black hole (disambiguation). ... Top: artists conception of a supermassive black hole tearing apart a star. ... This article or section is in need of attention from an expert on the subject. ... An Intermediate-mass black hole (IMBH) is a black hole whose mass is significantly more than stellar black holes (a few tens of the mass of Sun) yet far less than supermassive black holes (a few millions of the mass of Sun). ... A rotating black hole (Kerr black hole or Kerr-Newman black hole) is a black hole that possesses angular momentum. ... For the Red Dwarf episode, see White Hole (Red Dwarf episode). ... In astrophysics, the Gravastar theory is a proposal by Emil Mottola and Pawel Mazur to replace the black hole. ... In astronomy, the term compact star (sometimes compact object) is used to refer collectively to white dwarfs, neutron stars, other exotic dense stars, and black holes. ... Faster-than-light (also superluminal or FTL) communications and travel are staples of the science fiction genre. ... The chronology protection conjecture is a conjecture by the physicist Professor Stephen Hawking that the laws of physics are such as to prevent time travel (closed timelike curves) on all but sub-microscopic scales. ... This article is about the Alcubierre metric. ... For the story by Larry Niven, see Neutron Star (story). ... This article or section does not cite its references or sources. ... A Roman ring, in theoretical physics, is a type of wormhole where the time difference across its mouths is such that it may not allow a closed timelike curve (CTC), or closed-time loop. If these wormholes and their mouths are arranged in a suitable configuration, a closed time loop... It has been suggested that Deriving the Schwarzschild solution be merged into this article or section. ... The Schwarzschild radius (sometimes inappropriately referred to as the gravitational radius[1]) is a characteristic radius associated with every mass. ... Interaction in the subatomic world: world lines of pointlike particles in the Standard Model or a world sheet swept up by closed strings in string theory This box:      String theory is a model of fundamental physics, whose building blocks are one-dimensional extended objects called strings, rather than the zero... Two-dimensional analogy of space-time curvature described in General Relativity. ... Time travel is a concept that has long fascinated humanity—whether it is Merlin experiencing time backwards, or religious traditions like Mohammeds trip to Jerusalem and ascent to heaven, returning before a glass knocked over had spilt its contents. ... Timeline of black hole physics 1640 - Ismael Bullialdus suggests an inverse-square gravitational force law 1684 - Isaac Newton writes down his inverse-square Law of universal gravitation 1758 - Rudjer Josip Boscovich developes his Theory of forces, where gravity can be repulsive on small distances. ... A remote camera captures a close-up view of a Space Shuttle Main Engine during a test firing at the John C. Stennis Space Center in Hancock County, Mississippi Spacecraft propulsion is any method used to change the velocity of spacecraft and artificial satellites. ... The Krasnikov Tube is a theoretical mechanism for space travel involving the permanent warping of spacetime into superluminal tunnels. ...

References

• DeBenedictis, Andrew and Das, A.. On a General Class of Wormhole Geometries. arXiv eprint server. Retrieved on August 12, 2005.
• Dzhunushaliev, Vladimir. Strings in the Einstein's paradigm of matter. arXiv eprint server. Retrieved on August 12, 2005.
• Einstein, Albert and Rosen, Nathan. The Particle Problem in the General Theory of Relativity. Physical Review 48, 73 (1935).
• Fuller, Robert W. and Wheeler, John A.. Causality and Multiply-Connected Space-Time. Physical Review 128, 919 (1962).
• Garattini, Remo. How Spacetime Foam modifies the brick wall. arXiv eprint server. Retrieved on August 12, 2005.
• González-Díaz, Pedro F.. Quantum time machine. arXiv eprint server. Retrieved on August 12, 2005.
• González-Díaz, Pedro F.. Ringholes and closed timelike curves. arXiv eprint server. Retrieved on August 12, 2005.
• Khatsymosky, Vladimir M.. Towards possibility of self-maintained vacuum traversable wormhole. arXiv eprint server. Retrieved on August 12, 2005.
• Krasnikov, Serguei. Counter example to a quantum inequality. arXiv eprint server. Retrieved on August 12, 2005.
• Krasnikov, Serguei. The quantum inequalities do not forbid spacetime shortcuts. arXiv eprint server. Retrieved on August 12, 2005.
• Li, Li-Xin. Two Open Universes Connected by a Wormhole: Exact Solutions. arXiv eprint server. Retrieved on August 12, 2005.
• Morris, Michael S., Thorne, Kip S., and Yurtsever, Ulvi. Wormholes, Time Machines, and the Weak Energy Condition. Physical Review Letters 61, 1446–1449 (1988).
• Morris, Michael S. and Thorne, Kip S.. Wormholes in spacetime and their use for interstellar travel: A tool for teaching general relativity. American Journal of Physics 56, 395-412 (1988).
• Nandi, Kamal K. and Zhang, Yuan-Zhong. A Quantum Constraint for the Physical Viability of Classical Traversable Lorentzian Wormholes. arXiv eprint server. Retrieved on August 12, 2005.
• Ori, Amos. A new time-machine model with compact vacuum core. arXiv eprint server. Retrieved on August 12, 2005.
• Roman, Thomas, A.. Some Thoughts on Energy Conditions and Wormholes. arXiv eprint server. Retrieved on August 12, 2005.
• Teo, Edward. Rotating traversable wormholes. arXiv eprint server. Retrieved on August 12, 2005.
• Visser, Matt. The quantum physics of chronology protection by Matt Visser.. arXiv eprint server. Retrieved on August 12, 2005. An excellent and more concise review.
• Visser, Matt. Traversable wormholes: Some simple examples. Physical Review D 39, 3182–3184 (1989).

Physical Review is one of the oldest and most-respected scientific journals publishing research on all aspects of physics. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ...

External links

• What exactly is a 'wormhole'? answered by Richard F. Holman, William A. Hiscock and Matt Visser.
• Why wormholes? by Matt Visser.
• Wormholes in General Relativity by Soshichi Uchii.
• New Improved Wormholes by John G. Cramer
• White holes and Wormholes provides a very good description of Schwarzschild wormholes with graphics and animations, by Andrew J. S. Hamilton.
• Questions and Answers about Wormholes a comprehensive wormhole FAQ.
• Wormhole on arxiv.org
• [6] - Information about the theory the Large Hadron Collider could create a small wormhole. Possibly making time travel into the past possible.
• animation that simulates traversing a wormhole