The more-than-light backbone (also superluminal or FTL ) communication is the propagation of converging information or matter faster than the speed of light.
Special relativity theory implies that only particles with zero residual mass can travel at the speed of light. Tachyon, a particle whose velocity exceeds light, has been hypothesized, but its existence will violate causality, and the consensus of physicists is that they can not exist. On the other hand, what some physicists call the "real" or "effective" FTL depends on the hypothesis that the undistorted spacetime can allow problems to reach distant locations in less than light in a normal or undistorted spacetime.
According to current scientific theory, matter is required to travel at a speed slower than light (also subluminal or STL ) with respect to the spacetime region local distorted. It turns out that FTL is not excluded by general relativity; However, every physical possibility of FTL is clearly speculative. Examples of clear FTL proposals are Alcubierre drives and wormhole traversable. Video Faster-than-light
Non-FTL travel
In the context of this article, FTL is the transmission of information or matter faster than c , constantly equal to the speed of light in a vacuum, ie 299.792.458 m/s (by definition of meters) or about 186,282,397 miles per seconds. This is not the same as traveling faster than light, because:
- Some processes propagate faster than c , but can not carry information (see example in the next section).
- Light moves at a rate of c/n when it is not in a vacuum but goes through a medium with refractive index = n (causing refraction), and in some other particulate matter travel faster than c/n (but still slower than c ), leading to Cherenkov radiation (see phase velocity below).
None of these phenomena violate special relativity or create problems with causality, and thus do not qualify as FTL as described herein.
In the following examples, certain influences may appear faster than light, but they do not convey energy or information faster than light, so they do not violate special relativity.
Daily sky movements
For Earth-bound observers, objects in the sky complete a revolution around the Earth in a single day. Proxima Centauri, the nearest star outside the solar system, is about four light years away. In this frame of reference, where Proxima Centauri is considered to be moving in a circular trajectory with a radius of four light years, it can be described as having a vastly greater speed than c as the speed of the moving object in a circle is the product of the radius and the angular velocity. It is also possible in geostatic view, for objects such as comets vary their speed from subluminal to superluminal and vice versa simply because the distance from Earth varies. Comets may have an orbit that takes them to more than 1000 AU. Circular circles with a 1000 AU radius are larger than a day of light. In other words, a comet at such a distance is superluminal in a geostatic framework, and therefore non-inertial.
Spots and light shadows
If a laser beam sweeps away a distant object, a laser beam point can easily be made to move across an object at a speed greater than c . Similarly, images projected onto distant objects can be made to move across an object faster than c . In the case that no light travels from source to object faster than c , there is also no travel information faster than light.
FTL propagation visible from static field effect
Since there is no "retardation" (or deviation) from the apparent position of the source of the gravitational or electric field when the source is moving at a constant velocity, the static field effect "effect" may appear at a glance to be "transmitted" faster. of the speed of light. However, the uniform movement of the static source can be removed with changes in the frame of reference, causing the direction of the static field to change immediately, at all distances. This is not a "diffuse" position change, and thus this change can not be used to transmit information from its source. No information or material can be transmitted by FTL or transmitted from source to receiver/observer by electromagnetic field.
Closing speed
The rate at which two objects move in one closer frame of reference is called mutual velocity. This may be nearly twice the speed of light, as in the case of two particles moving near the speed of light in the opposite direction by paying attention to the frame of reference.
Imagine two fast moving particles approaching each other from the opposite side of the collider type particle accelerator. The closing speed will be the rate at which the distance between the two particles decreases. From the standpoint of the observer standing at rest relative to the accelerator, this level will be slightly less than twice the speed of light.
Special relativity does not prohibit this. It tells us that it is wrong to use Galilean relativity to calculate the velocity of one of the particles, as would be measured by the observer traveling along with the other particle. That is, special relativity gives the right formula to calculate the relative speed.
Ini instruktif untuk menghitung kecepatan relatif partikel yang bergerak pada v dan - v dalam bingkai akselerator, yang sesuai dengan kecepatan penutupan 2 v Ãâ & gt; Ãâ c . Mengekspresikan kecepatan dalam satuan c ,? Ãâ = v / c :
Kecepatan yang tepat
If a spacecraft moves to the planet one light year (measured in Earth's breaking frame) away from Earth at high speeds, the time it takes to reach the planet could be less than a year as measured by the wanderer's hours (though it will always be more than one year measured by clock on Earth). The value obtained by dividing the distance traveled, as determined in the Earth's frame, at the time taken, measured by the travel clock, is known as the proper velocity or exact speed. There is no limit to the exact speed value because the exact speed does not represent the measured speed in a single inertial framework. Light signals that leave Earth at the same time as travelers will always get to the destination before the explorer.
Possible distance from Earth
Since one can not travel faster than light, one can conclude that humans can not travel farther from Earth than 40 light years if the traveler is active between the ages of 20 and 60. A traveler can never achieve more than very few star systems that exist within the 20-40 light-years from Earth. This is the wrong conclusion: because of time dilation, travelers can travel thousands of light years for their active 40 years. If the spacecraft accelerates at a constant 1 g (in a self-changing reference frame), it will, after 354 days, reach speeds just below the speed of light (for observers on Earth), and the widening of time will increase their lifespan by thousands Earth, judging by the reference system of the Solar System, but the subjective life span of tourists will not change. If a traveler returns to Earth, he will land thousands of years into Earth's future. Their speed will not look higher than the speed of light by observers on Earth, and travelers will not measure their speed as higher than the speed of light, but will see the long contractions of the universe in the direction of their journey. And when the traveler turns to return, the Earth will seem to experience more time than the traveler does. Thus, while their ordinary coordinate velocity can not exceed c , the correct speed (the distance seen by the Earth divided by the right time) can be much greater than c . This is seen in statistical studies of muons that travel much farther than c times their half-life (at rest), when traveling approaches c .
The speed phase above c
The phase velocity of electromagnetic waves, when traveling through media, can routinely exceed c , the vacuum speed of light. For example, this happens in most eyeglasses at X-ray frequencies. However, the wave phase velocity corresponds to the propagation velocity of the theoretical (monochromatic pure) single frequency component of the wave at that frequency. Such wave components must be unlimited and amplitude constant (if not completely monochromatic), so they can not convey any information. Thus the phase velocity above c does not imply signal propagation at speeds above c .
Group speed above c
The speed of the wave group (for example, light) can also exceed c in some circumstances. In such cases, which usually at the same time involves rapid intensity attenuation, the maximum pulse envelope can run at speeds above c . However, even this situation does not imply signal propagation at speeds above c , although one may be tempted to associate a maximum pulse with a signal. The latter association has been proven to be misleading, since information about the arrival of the pulse can be obtained before the maximum pulse arrives. For example, if multiple mechanisms allow full transmission of the main part of the pulse while greatly weakening the maximum pulse and everything behind (distortion), the maximum pulse effectively shifts forward in time, while the information on the pulse does not come faster. from c without this effect. However, the group velocity may exceed c in some parts of the Gaussian beam in a vacuum (without damping). Diffraction causes the peak pulse to propagate faster, while the overall power is not.
Universal expansion
The expansion of the universe causes distant galaxies to recede from us faster than the speed of light, if the exact distance and cosmological time are used to calculate the speed of these galaxies. However, in general relativity, speed is a local idea, so speed calculated using adjacent coordinates does not have a simple relationship with locally calculated speeds. (See distance for discussion of different notions of 'speed' in cosmology.) The rules that apply to relative speeds in special relativity, such as the rule that relative velocities can not increase past the speed of light, do not apply to relative speeds at comoving coordinates, which often described in terms of "space expansion" between galaxies. This expansion rate is estimated to be at its peak during the inflation period estimated to occur in a small fraction of the second after the Big Bang (the model indicates the period will be from about 10 soup -36 seconds after the Big Bang to about 10 -33 seconds), when the universe may have developed rapidly with a factor of about 10 20 to 10 30 .
There are many galaxies visible on telescopes with redshift figures of 1.4 or higher. All of this is currently traveling away from us at speeds greater than the speed of light. Since the Hubble parameters decline over time, there are actually cases where galaxies are moving away from us faster than the light actually emits signals that eventually reach us.
According to Tamara M. Davis, "Our effective particle horizon is a cosmic microwave background (CMB), at a z ~ 1100 red shift, since we can not see beyond the last scattering surface, although the latter scattering surface is not fixed at fixed coordinates. the current recession velocity from the points from which the CMB is emitted is 3.2c At the time of their emission speed is 58.1c, assuming (? M, ??) = (0.3.0.7) So we routinely observe objects that recede more fast from the speed of light and the Hubble ball is not the horizon. "
However, as the expansion of the universe accelerates, it is projected that most galaxies will eventually cross a kind of cosmological event horizon in which the light they emit through that point will never reach us anytime in the infinite future, since no light ever reach the point where the "strange speed" toward us exceeds the expansionary speed away from us (these two sense velocities are also discussed in Growing distance # Use of the right distance). The current distance to the cosmological event horizon is about 16 billion light-years away, meaning that signals from current events will eventually be able to reach us in the future if the event is less than 16 billion light years away, but the signal will never reach to us if the event is more than 16 billion light years away.
astronomical observations
A real superluminal movement is observed in many radio galaxies, blazars, quasars and more recently in microquasars. The effect is predicted before being observed by Martin Rees and can be explained as an optical illusion caused by a partially moving object toward the observer, when the speed calculation assumes it is not. This phenomenon does not contradict the special theory of relativity. Corrected calculations show these objects have speeds close to the speed of light (relative to our reference frame). They are the first example of a large number of masses moving near the speed of light. Earth-bound laboratories are only able to accelerate a small number of elementary particles to such speeds.
Quantum mechanics
Certain phenomena in quantum mechanics, such as quantum entanglement, may give the impression of superficial communication enable information faster than light. According to the theorem without communication, this phenomenon does not allow correct communication; they just let two observers in different locations see the same system simultaneously, without any way of controlling what it sees. The collapse of the wave function can be seen as the quantum decoherence epiphenomenon, which in turn is nothing more than the influence of local time evolution underlying the wave function of the system and all its environments. Since the underlying behavior does not violate local causality or allows FTL communication, then there is no additional effect of the collapse of the wave function, whether real or clear.
The uncertainty principle implies that individual photons can travel for short distances at a somewhat faster (or slower) speed than c , even in a vacuum; this possibility should be taken into account when calculating Feynman diagrams for particle interactions. However, it was shown in 2011 that one photon can not travel faster than c . In quantum mechanics, virtual particles can move faster than light, and this phenomenon is related to the fact that the effects of static fields (mediated by virtual particles in quantum terms) can travel faster than light (see section on the static field above). However, these macroscopic fluctuations average out, so photons travel in a straight line with long distances (ie, non-quantum), and they travel at the speed of light on average. Therefore, this does not imply the possibility of transmitting superluminal information.
There are various reports in the popular press experiment on the faster transmission of light in optics - most often in the context of some kind of quantum tunnel phenomenon. Typically, such reports relate to group phase velocities or speeds faster than light vacuum speeds. However, as stated above, the superluminal phase velocity can not be used for transmitting information faster than light.
Hartman effect
Hartman's effect is a tunneling effect through a barrier in which the tunneling time tends to be constant for major obstacles. This was first described by Thomas Hartman in 1962. This could, for example, be a gap between two prisms. When the prism touches, the light will immediately penetrate, but when there is a gap, light is refracted. There is a non-zero probability that the photons will dig in the gap rather than follow the refraction path. For the large gap between the prisms, the tunneling time approaches the constant and thus the photons appear to be crossed at superluminal speeds.
However, an analysis by Herbert G. Wins from the University of Michigan shows that Hartman effect can not really be used to violate relativity by sending signals faster than c , since tunneling time "should not be attributed to speed because reverse waves do not propagate ". The evanescent wave in Hartman effect is due to virtual particles and non-propagation static fields, as mentioned in the above section for gravity and electromagnetism.
Casimir effect
In physics, the Casimir effect or Casimir-Polder style is the physical force given between separate objects because of the resonance of the vacuum energy in the space between objects. This is sometimes explained in terms of virtual particles that interact with objects, because of the mathematical form of one possible way to calculate the strength of the effect. Because the power of force falls rapidly with distance, it can only be measured when the distance between objects is very small. Since the effect is due to virtual particles that mediate the static field effect, it is subject to comments about the static fields discussed above.
EPR Paradigm
The EPR paradigm refers to the famous thought experiments of Einstein, Podolski and Rosen which were first experimentally realized by Alain Aspect in 1981 and 1982 in Aspect experiments. In this experiment, measuring the state of one of the quantum systems of the entangled couple appears to instantly force another (perhaps far) system to be measured in a complementary state. However, no information can be sent in this way; the answer to whether measurement actually affects other quantum systems goes down to the interpretation of the quantum mechanics that a person subscribes to.
Experiments conducted in 1997 by Nicolas Gisin at the University of Geneva have demonstrated a non-local quantum correlation between separate particles over 10 kilometers. But as mentioned earlier, the non-local correlations seen in attachments can not really be used to transmit classical information faster than light, so relativistic causality is maintained; see the theorem without communication for more information. A 2008 quantum physics experiment also conducted by Nicolas Gisin and his colleagues in Geneva, Switzerland has determined that in the hypothetical non-local hidden variable theory whatever the speed of a non-local quantum connection (what Einstein calls "creepy action in the distance") at least 10,000 times the speed of light.
Pending quantitative eraser
Quantum delayed option deletion (Marlan Scully experiment) is a version of the EPR paradox in which observation or no interference after the passage of photons through a double slit experiment depends on the observation conditions of the first photons being entangled with the first. The characteristic of this experiment is that the observation of the second photon can occur at a later time than the first photon observation, which may give the impression that the measurement of the photon then "retroactively" determines whether the previous photon indicates interference. or not, although interference patterns can only be seen by correlating the measurements of the two members of each pair and so that they can not be observed until both photons have been measured, ensuring that experiments that are only observing photons through the gap do not obtain information about other photons by way of FTL or back-in- time.
Maps Faster-than-light
Superluminal communication
The faster communication of light is, by Einstein's theory of relativity, equivalent to time travel. According to Einstein's special theory of relativity, what we measure as the speed of light in a vacuum (or void vacuum) is actually the fundamental physical constants c . This means that all inertial observers, regardless of their relative velocity, will always measure zero-mass particles such as photons running in c in a vacuum. This result means that measurements of time and velocity in different frames are no longer associated with only a constant shift, but instead are related to the Poincarà © transformation. This transformation has important implications:
- The relativistic momentum of massive particles will increase at such a speed that at the speed of light the object will have infinite momentum.
- To speed objects from non-zero rest masses to c will take unlimited time with limited acceleration, or unlimited acceleration for a limited time.
- However, such acceleration requires unlimited energy.
- Some observers with relatively sub-light movements would disagree about what happened first of two events separated by intervals such as space. In other words, any faster journey of light will be seen as a trip backwards in time in some other frame of reference, equally applicable, or need to assume the speculative hypothesis of possible violation of Lorentz on a scale not currently observable (for example the Planck scale ). Therefore, any theory that enables the "true" FTL also has to overcome the passage of time and all related paradoxes, or else to consider Lorentz invariance to be symmetry of thermodynamic statistical properties (hence the broken symmetry on some scale is not currently observable).
- In special relativity, light coordinate velocity is only secured c in the inertial framework; in a non-inertial frame the coordinate speed may differ from c . In general relativity, no coordinate system in large regions of curved spacetime is "inertia", so it is permissible to use global coordinate systems where objects move faster than c , but in the local environment from any point in the curved spacetime we can define "local inertia frame" and the speed of local light will be c in this frame, with large objects moving through this local environment always having a speed less than c in the frame of local inertia.
Justifications
relative permittivity or permeability less than 1
Kecepatan cahaya
related to the permittivity of vacuum ? 0 and vacuum permeability ? 0 . Therefore, not only the phase velocity, group velocity and the velocity of the energy flow of the electromagnetic waves but also the speed of the photon can be faster than c in a special material having a constant permeability or a permeability of less value in a vacuum.
Casimir vacuum and quantum tunnel
Einstein's equation of special relativity postulates states that the speed of light in a vacuum is invariant in the framework of inertia. That is, it will be the same from a moving reference frame with constant speed. The equation does not specify any special value for the speed of light, which is an experimentally determined quantity for a fixed length unit. Since 1983, SI length units (meters) have been defined using the speed of light.
Experimental determination has been done in a vacuum. However, the emptiness that we know is not the only emptiness that may exist. Vacuum has energy associated with it, called only vacuum energy, which may be altered in certain cases. When the vacuum energy is lowered, the light itself is predicted to be faster than the standard value c . This is known as the Scharnhorst effect. Such a vacuum can be produced by carrying two very fine metal plates together at a distance of near diameter atoms. This is called the Casimir vacuum. Calculations imply that light will be faster in such a vacuum by a very small amount: photons moving between two plates 1 micrometer apart will increase the photon velocity by only about one part in 10 36 . Therefore, there is no experimental verification of these predictions. A recent analysis argues that the Scharnhorst effect can not be used to send backward information in time with a set of dishes because the plate break frames will determine "preferred frames" for FTL signaling. However, with several pairs of moving plates relative to each other, the authors noted that they had no argument that could "guarantee the absence of total causality offenses", and led to the suspicion of protection of speculative Hawking chronology which showed that the virtual particle loop feedback would create "singularities uncontrolled in quantum-energy quantum stresses "at the limit of potential time machines, and thus would require the theory of quantum gravity to fully analyze. Other authors argue that Scharnhorst's original analysis, which seems to indicate the possibility of faster than- c signals, involves estimates that may be false, so it is unclear whether this effect can really increase the signal speed at all.
The physicists GÃÆ'ünter Nimtz and Alfons Stahlhofen, from the University of Cologne, claim to have violated experimental relativity by transmitting photons faster than the speed of light. They say they have done experiments in which microwave photons - relatively low light energy packets - travel "instantaneously" between a pair of prisms that have been moved up to 3Ã, ft (1 m) apart. Their experiments involve optical phenomena known as "evanescent", and they claim that because evanescent modes have imaginary wave numbers, they represent "mathematical analogies" for quantum tunnels. Nimtz also claims that "evanescent modes are not fully explained by Maxwell's equations and quantum mechanics must be considered." Other scientists such as Herbert G. Winful and Robert Helling argue that there is actually no quantum mechanics about Nimtz's experiments, and that the results can be fully predicted by classical electromagnetic equations (Maxwell's equations).
Nimtz told New Scientist magazine: "For now, this is the only offense of special relativity that I know of." However, other physicists say that this phenomenon does not allow information to be transmitted faster than light. Aephraim Steinberg, a quantum optics expert at the University of Toronto, Canada, uses a train analogy that travels from Chicago to New York, but lowers the train at each station along the way, so the main center that always shrinks the train moving forward at each stop; in this way, the center speed of the train exceeds the speed of any car.
Herbert G. Winful argues that railroad analogy is a variant of "reshaping arguments" for superluminal tunneling speeds, but he goes on to say that this argument is in fact unsupported by experiments or simulations, which actually indicates that the transmitted pulses have length and shape equal to the incident pulse. In contrast, Winful argues that group delay in tunneling is not actually a transit time for pulses (the spatial length must be greater than the length of the boundary so that the spectrum is narrow enough to allow tunneling), but instead the lifetime of the energy stored in standing waves formed within the barrier. Since the energy stored in the barrier is less than the energy stored in barrier-free areas of the same length due to destructive disturbance, the group delay for energy to escape from the barrier area is shorter than would be in free space, which according to Winful is the explanation for tunneling superluminal.
A number of authors have published papers arguing on Nimtz's opinion that Einstein's causality was violated by his experiments, and there are many other papers in the literature that discuss why quantum tunnels are not considered to violate causality.
It was later claimed by the Keller group in Switzerland that tunneling of particles did occur in real time zero. Their test involves electron tunneling, in which the group believes a relativistic prediction for tunneling time should be 500-600 attoseconds (attosecond is one quintillionth (10 -18 ) a second). All that can be measured is 24 attoseconds, which is the limit of test accuracy. Again, though, other physicists believe that tunneling experiments in which particles appear to spend a very short time in the barrier are in fact fully compatible with relativity, although there is disagreement as to whether the explanation involves the re-forming of wave packets or other effects.
Release relativity (absolute)
Due to strong empirical support for special relativity, any modification should be subtle and difficult to measure. The most notable endeavor is double relativity, which holds that the length of Planck is also the same in all terms of reference, and is attributed to the work of Giovanni Amelino-Camelia and JoÃÆ'à £ o Magueijo.
There is a speculative theory that claims inertia is produced by the combined mass of the universe (eg, the Mach principle), which implies that the universe's resting frame may be favored by conventional laws of nature. If confirmed, this would imply special relativity is an approximation to a more general theory, but since the relevant comparison would (by definition) be outside the observable universe, it is difficult to imagine (let alone build) experiments to test this hypothesis.
Time Distortion
Although the special theory of relativity prohibits objects having a relative velocity greater than the speed of light, and general relativity reduces special relativity in the local sense (in small regions of spacetime where curvature is negligible), general relativity does allow the space between distant objects to expand in such a way that they have a "recession velocity" that exceeds the speed of light, and it is thought that galaxies that are at a distance of more than about 14 billion light-years from us today have faster recession speeds than light. Miguel Alcubierre theorized that it would be possible to create an Alcubierre drive, where the ship would be flanked in a "warp bubble" where the space in front of the bubble quickly contracts and the space behind quickly develops, with the result that bubbles can reach destinations much faster than rays that move outside the bubbles, but without objects inside the bubbles, local travel is faster than light. However, some objections filed against Alcubierre's drive seem to rule out the possibility of actually using them in practical mode. Another possibility predicted by general relativity is the passable wormhole, which can create shortcuts between points spaced far in space. As with Alcubierre drives, travelers traveling through the wormhole will not locally move faster than the light running through the wormhole beside them, but they will be able to reach their destination (and return to their original location) faster than light moving outside the wormhole.
Dr Gerald Cleaver, professor of physics at Baylor University, and Richard Obousy, a Baylor graduate student, theorized that manipulating the extra spatial dimension of string theory around the spacecraft with enormous amounts of energy would create "bubbles" that could cause the ship to travel more faster than the speed of light. To create these bubbles, physicists believed to manipulate the dimensions of space 10 would convert dark energy into three large spatial dimensions: height, width and length. Cleaver says positive dark energy is currently responsible for accelerating the rate of expansion of our universe as time passes.
Heim Theory
In 1977, a paper on the theory of Heim theorized that it is possible to travel faster than light by using magnetic fields to enter the higher dimensional space.
Lorentz symmetry violation
The possibility that Lorentz's symmetry may be violated has been seriously considered in the last two decades, especially after the development of a realistic, effective field theory that illustrates the possibility of this violation, called the Standard Model Extension. This general framework has enabled experimental searching with ultra-high cosmic ray experiments and experiments in gravity, electrons, protons, neutrons, neutrinos, mesons, and photons. Breaking rotation and encouraging invariance leads to directional dependence in theory as well as unconventional energy dependence that introduces new effects, including the Lorentz-breaking neutrino oscillation and modifications to the dispersion relations of different particle species, which can naturally make particles move faster than light.
In some models of damaged Lorentz kesimetrian, it is postulated that symmetry is still built into the most basic laws of physics, but that the spontaneous disconnection of the invariant Lorentz shortly after the Big Bang can leave the "field of relics" throughout the universe that causes the particles to behave differ depending on the speed relative to the field; However, there are also some models where Lorentz symmetry breaks down in a more basic way. If Lorentz symmetry can cease to be fundamental symmetry on the Planck scale or on some other fundamental scale, it is conceivable that particles with critical velocities different from the speed of light become the main constituents of matter.
In the current Lorentz symmetry violation model, phenomenological parameters are expected to depend on energy. Therefore, as widely recognized, existing low energy limits can not be applied to high energy phenomena; however, many searches of Lorentz violations at high energy have been performed using Standard Model Extensions. The violation of the Lorentz symmetry is expected to become stronger as one gets closer to the fundamental scale.
The superfluid theory of physical emptiness
In this approach, the physical void is seen as a non-relativistic quantum superfluid while the Lorentz symmetry is not the exact symmetry of nature but rather the approximate description which applies only to minor fluctuations of the superfluid background. In the framework of the approach, a proposed theory in which a physical void is supposed to be a quantum Bose liquid whose ground-wave function is described by the logarithmic Schreederding equation. It shows that relativistic gravitational interaction emerges as a small collective amplitude excitation mode whereas relativistic base particles can be described by particle-like modes within low momentum limits. The important fact is that at very high speeds, the behavior of modes such as particles becomes different from the relativistic ones - they can reach the speed limit of light on the limited energy; also, faster propagation of light is possible without requiring moving objects to have imaginary masses.
Flight time of neutrino
MINOS experiment
In 2007, the MINOS collaboration reported the 3 GeV neutrino flight time measurements that resulted in speeds exceeding light with a 1.8-sigma significance. However, such measurements are considered statistically consistent with neutrinos running at the speed of light. Once the detector for the project is upgraded in 2012, MINOS corrects their preliminary results and finds deals at the speed of light. Further measurements will be made.
OPERA neutrino anomaly
On September 22, 2011, the precast of the OPERA Collaboration showed detection of 17 and 28 GeV muon neutrinos, sent 730 kilometers (454 miles) from CERN near Geneva, Switzerland to Gran Sasso National Laboratory in Italy, traveled faster than light by relative amounts of 2, 48ÃÆ' â ⬠"10 -5 (about 1 in 40,000), statistics with 6.0-sigma significance. On November 17, 2011, a second follow-up experiment by OPERA scientists confirmed their preliminary results. However, scientists are skeptical about the results of this experiment, whose significance is debatable. In March 2012, the ICARUS collaboration failed to reproduce OPERA results with their equipment, detecting neutrino travel time from CERN to Gran Sasso National Laboratory that is indistinguishable from the speed of light. Then the OPERA team reported two flaws in their equipment that caused errors far beyond their original confidence interval: incorrectly installed optical fiber cables, which led to measurements that seemed to be faster than light, and the clock oscillator was too fast.
Tachyons
In special relativity, it is not possible to accelerate the object to the speed of light, or for large objects to move at the speed of light. However, there may be objects that always move faster than light. The hypothetical base particles with this property are called tachyonic particles. Attempts to measure them fail to produce particles faster than light, and instead illustrate that their presence leads to instability.
Various theorists have suggested that neutrinos may have tachyonic properties, while others have debated the possibility.
Exotic material
Mempertimbangkan dan , hubungan energi-momentum dari partikel tersebut sesuai dengan hubungan dispersi berikut
- ,
That is, such waves can penetrate the light barrier under certain conditions.
General relativity
General relativity developed after special relativity to include concepts like gravity. It maintains the principle that no object can accelerate to the speed of light within the frame of reference of any accidental observer. However, this allows distortion in spacetime that allows objects to move faster than light from the viewpoint of a distant observer. One such distortion is the Alcubierre drive, which can be thought of as generating ripples in space-time that carry objects with it. Another possible system is the wormhole, which connects two distant locations such as a shortcut. Both distortions will need to create a very strong curvature in the region of time that is very localized and their gravitational field will be very large. To counter the unstable nature, and prevent the distortion from collapsing under their own 'weight', one needs to introduce hypothetical exotic matter or negative energy.
General relativity also recognizes that faster travel means of light can also be used for time travel. This poses a problem with causality. Many physicists believe that the above phenomena is impossible and that the theory of future gravity will prohibit them. One theory holds that a stable wormhole is possible, but that any attempt to use a wormhole network to violate causality would result in its destruction. In string theory, Eric G. Gimon and Petr Ho? Ava has declared that in the five-dimensional universe of G̮'̦del supersymmetry, quantum correction of general relativity effectively cuts off spacetime with causality-breaking the near-closed time curve. Specifically, in quantum theory there is a splattered supertube that cuts off the spacetime in such a way that, although in full spacetime the closed time curve passes through each point, there is no complete indentation in the interior region bounded by the tube.
The speed of variable light
In physics, the speed of light in a vacuum is assumed as a constant. However, there is a hypothesis that the speed of light varies.
The speed of light is the quantity of dimensions and so forth, as emphasized in this context by JoÃÆ'à ° o Magueijo, it can not be measured. The quantities measured in physics are, without exception, dimensionless, although they are often constructed as dimensional quantity ratios. For example, when a mountain's height is measured, what is actually measured is its height ratio to the stick's length. The conventional SI unit system is based on the seven dimensions of the basic dimensions, namely distance, mass, time, electric current, thermodynamic temperature, number of substances, and light intensity. These units are defined as independent and can not be explained to each other. As an alternative to using a particular unit system, one can reduce all measurements to dimensionless quantities expressed in the ratio between measured quantities and fundamental constants such as Newton's constant, light velocity and Planck's constant; Physicists can define at least 26 constants without dimensions that can be expressed in terms of these ratios and which are currently considered independent of each other. By manipulating the basic dimensional constants, we can also construct Planck time, Planck length, and Planck energy which create a good unit system for expressing dimensional measurements, known as Planck units.
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