A more recent paper by Carlos Barceló, Stefano Finazzi, and Stefano Liberati makes use of quantum theory to argue that the Alcubierre Drive at FTL velocities is impossible ; mostly due to extremely high temperatures caused by Hawking radiation destroying anything inside the bubble at superluminal velocities and leading to instability of the bubble itself.

Faster-than-light travel is often used in science fiction to denote a wide variety of imaginary propulsion methods, though not necessarily based on the Alcubierre drive or any other physical theory.

Some science-fiction works, particularly of the " hard " genre, have explicitly made use of the Alcubierre theory, such as Stephen Baxter's novel Ark.

The Alcubierre drive theory is proposed as a possible reason for events occurring in the graphic novel " Orbiter " by Warren Ellis and Colleen Doran.

The Alcubierre drive is the only feasible concept, highly hypothetical, that exists nowadays and that is able in theory to impulse a spacecraft to speeds faster than light.

In general relativity, one often first specifies a plausible distribution of matter and energy, and then finds the geometry of the spacetime associated with it ; but it is also possible to run the Einstein field equations in the other direction, first specifying a metric and then finding the energy-momentum tensor associated with it, and this is what Alcubierre did in building his metric.

Some doubt has been cast upon whether sufficient quantity of exotic matter needed for wormholes and Alcubierre bubbles can exist.

In particular, Alcubierre has shown that even when the ship is accelerating, it travels on a free-fall geodesic.

The Ian Douglas " Star Carrier " series exclusively uses the Alcubierre drive as the main mode of interstellar travel.

By January 1937 he was at Alcubierre above sea level, in the depth of winter.

A valid solution for faster-than-light travel which models the warp drive concept, called the Alcubierre drive, was formulated by physicist Miguel Alcubierre in 1994.

Examples of FTL proposals are changing the " frequency " of mass to a higher state by applying high-frequency waves of energy, the Alcubierre drive, and the traversable wormhole, although the physical plausibility of some of these solutions is uncertain.

The Alcubierre drive ( or Alcubierre metric see: Metric tensor ) is a speculative idea based on a valid solution of the Einstein field equations as proposed by Miguel Alcubierre by which a spacecraft may achieve faster-than-light ( FTL ) travel, making travel to other stars more feasible.

In 1994 Alcubierre proposed a way of changing the geometry of space by creating a wave which would cause the fabric of space ahead of a spacecraft to contract and the space behind it to expand.

The particular form that Alcubierre studied is defined by:

Coule has argued that schemes such as the one proposed by Alcubierre are infeasible as matter placed en route of the intended path of a craft has to be placed at superluminal speed.

These results seem to make it rather unlikely that one could construct Alcubierre warp drives using exotic matter generated by quantum effects.

* Alcubierre metric ( which has been used as a speculative toy model of effectively superluminal space travel, as in the warp drive from Star Trek ).

* Alcubierre, Miguel ; The Warp Drive: Hyper-Fast Travel Within General Relativity, Classical and Quantum Gravity 11 ( 1994 ), L73 – L77

Miguel Alcubierre theorized that it would be possible to create an Alcubierre drive, in which a ship would be enclosed in a " warp bubble " where the space at the front of the bubble is rapidly contracting and the space at the back is rapidly expanding, with the result that the bubble can reach a distant destination much faster than a light beam moving outside the bubble, but without objects inside the bubble locally traveling faster than light.

However, several objections raised against the Alcubierre drive appear to rule out the possibility of actually using it in any practical fashion.

As with the Alcubierre drive, travelers moving through the wormhole would not locally move faster than light which travels through the wormhole alongside them, but they would be able to reach their destination ( and return to their starting location ) faster than light traveling outside the wormhole.

One such distortion is the Alcubierre drive, which can be thought of as producing a ripple in spacetime that carries an object along with it.

Two-dimensional visualization of the Alcubierre drive, showing the opposing regions of expanding and contracting spacetime that displace the central region.

Thus the mathematical formulation of the Alcubierre metric does not contradict the conventional claim that the laws of relativity do not allow a slower-than-light object to accelerate to faster-than-light speeds.

The Alcubierre drive, however, remains a hypothetical concept with seemingly insuperable problems: Though the amount of energy required is no longer thought to be unobtainably large, there is no method to create a warp bubble in a region that does not already contain one, and there is no method to move from the warp-bubble once having arrived at an intended destination.

The Alcubierre metric defines the warp drive spacetime.

Alcubierre chose a specific form for the function f, but other choices give a simpler spacetime exhibiting the desired " warp drive " effects more clearly and simply.

For those familiar with the effects of special relativity, such as Lorentz contraction and time dilation, the Alcubierre metric has some apparently peculiar aspects.

Alcubierre interpreted his " warp bubble " in terms of a contraction of " space " ahead of the bubble and an expansion behind.

But in this case, the Alcubierre Drive vessel is not able to go dashing around the galaxy at will.

Thus, according to Coule, an Alcubierre Drive is required in order to build an Alcubierre Drive.

Coule argues that an analogous objection will apply to any proposed method of constructing an Alcubierre Drive.

procedures change rapidly and parental confidence probably exceeds anything warranted by established psychological theory.

As such, critical theory was left, in Jürgen Habermas ’ words, without " anything in reserve to which it might appeal ; and when the forces of production enter into a baneful symbiosis with the relations of production that they were supposed to blow wide open, there is no longer any dynamism upon which critique could base its hope.

Ethical naturalism stands in opposition to ethical non-naturalism, which denies that moral terms refer to anything other than irreducible moral properties, as well as to all forms of moral anti-realism, including ethical subjectivism ( which denies that moral propositions refer to objective facts ), error theory ( which denies that any moral propositions are true ), and non-cognitivism ( which denies that moral sentences express propositions at all ).

Mutualists hold a labor theory of value, arguing that in exchange labor should always be worth " the amount of labor necessary to produce an article of exactly similar and equal utility ," and considering anything less to be exploitation, theft of labor, or usury.

As a result, even though in theory other search algorithms may be faster than linear search ( for instance binary search ), in practice even on medium sized arrays ( around 100 items or less ) it might be infeasible to use anything else.

If on the other hand, we define the notion of what is physical based some future idealized physics, we have not effectively defined anything at all because nobody knows what entities a future physical theory might postulate.

If anything, if a part of objective reality, theorization and systemization to Post-structuralists was an exponent of larger, more nebulous patterns of control in social orders – patterns that could not be encapsulated in theory without simultaneously conditioning it.

In the first place, he says that the theory of utility is true by definition and thus does not really add anything meaningful.

Value theory encompasses a range of approaches to understanding how, why and to what degree people value things ; whether the thing is a person, idea, object, or anything else.

That a set can capture the notion of the extension of anything is the idea behind the axiom of extensionality in axiomatic set theory.

If anything is specifically human in this theory, it is the flexibility and adaptability of humans.

The theory can be considered a form of Platonism in that it posits the existence of mathematical entities, but can also be considered a mathematical monism in that it denies that anything exists except mathematical objects.

In game theory, the Nash equilibrium ( named after John Forbes Nash, who proposed it ) is a solution concept of a game involving two or more players, in which each player is assumed to know the equilibrium strategies of the other players, and no player has anything to gain by changing only his own strategy unilaterally.

( the only exceptions being the Cod Wars, the Turbot War and Operation Fork — all of which had no casualties ) Jack Levy ( 1988 ) made an oft-quoted assertion that the theory is " as close as anything we have to an empirical law in international relations ".

Put in simpler words, the particles postulated by the de Broglie – Bohm theory are anything but " hidden " variables: they are what the objects we see in everyday experience are made of ; it is the wavefunction itself which is " hidden " in the sense of being invisible and not-directly-observable.

# the ontology which is concerned with what, if anything, the interpreted theory is " really about " and

" In theory, anything else could be aired.

The theory stresses the subject's longing for a completeness which the film may appear to offer through identification with an image, although Lacanian theory also indicates that identification with the image is never anything but an illusion and the subject is always split simply by virtue of coming into existence ( Aphanisis ).

However, Sigmund Feist ( 1909 ) rejects the theory on etymological grounds, as does Albert Morley Sturtevant ( 1951 ) on the grounds of major difficulties, and their points have led Bruce Lincoln ( 1977 ) to comment that " there is no reason whatever to contend that nagl-does not have its usual meaning of " nail " and that Naglfar is anything other than the nail-ship, just as Snorri describes it.

This theory of knowledge suffered a significant setback with the discovery of Gettier problems, situations in which the above conditions were seemingly met but that many philosophers disagree that anything is known.

The blacklisting of some Protestant scholars even when writing on subjects a modern reader would consider outside the realm of dogma meant that, unless they obtained a dispensation, obedient Catholic thinkers were denied access to the botanist Conrad Gesner's Historiae animalium or the botanical works of Otto Brunfels, those of the medical scholar Janus Cornarius, to Christoph Hegendorff or Johann Oldendorp on the theory of law, Protestant geographers and cosmographers like Jacob Ziegler or Sebastian Münster, as well as anything by Protestant theologians like Martin Luther, John Calvin or Philipp Melancthon.