I argue that the controversy is a result of a lack of clarity as to what it means to signal, and i propose a criterion. Simple definitions let be the angular velocity and k the wavenumber1, then the phase. This is why in an introduction to general relativity it is of. Consider a blob of plasma that is moving at a speed valong a direction that makes an angle.
For instance a schwarzschild solution to einstein equations written in schwarzschild coordinates has a peculiar property that time and radial coordinates change their metric signs at the event horizon. Some experiments, performed at berkeley, cologne, florence, vienna, orsay and rennes led to the claim that something seems to travel with a group velocity larger than the speed c of light in vacuum. I think these are very important aspects of special relativity, but from a pedagogical standpoint it is preferable to separate them from the basics, which are not dependent on the properties of the observer. Proceedings of the first international conference on. However, you can show quite generally that it is impossible to surpass the speed of light c by adding two speeds that are less than c, regardless of how close they are. Relativity and impossibility of superluminal motion.
On the contrary, taking into account a superluminal system, it is possibleat least theoreticallyto derive some of the postulates of quantum mechanics from the special theory of relativity. The relativity and ftl travel faq was created mainly for the rec. Xk, general relativity is a beautiful scheme for describing the gravitational. Apparent superluminal motion an overview sciencedirect. That just comes from special relativity, which is part of general relativity. Warp drives are solutions of the einstein field equations that allows superluminal travel within the framework of general relativity. In section 6, we present an axiom system for dynamics of special relativity theory. Though some of these criticisms had the support of reputable scientists, einsteins theory of relativity is now accepted by the scientific community. Nevertheless, it has a reputation of being extremely di. Lecture notes relativity physics mit opencourseware. Causality and superluminal light 1 introduction in general.
The existence of superluminal particles is consistent with. However, a couple of questions spring to mind, not least how can this superluminal bubble of a warp drive be consistent with the rules of relativity. In particular, such a source would have to violate the self consistent achronal averaged null energy. See leff and rex 1990 for an overview of the history of the demon, and earman and norton 1998, 1999 and weinstein 2003 for critical discussion. A physical law has a form in newtonian physics, another form in the relativity theory, and different form at superluminal. The superluminal solutions appear quite naturally in general relativity.
Adrian sfarti introduction there is a lot of confusion swirling around the socalled superluminal experiments. A distant object can appear to travel faster than the speed of light across our line of sight, provided that it has some component of motion towards us as well as perpendicular to our line of sight. A 1 institute of cosmology, department of physics and astronomy, tufts university we study large families of theories of interacting spin 2 particles from the point of view of causality. Superluminal transformations in general relativity. The sunlights red shift 1911, the perihelion motion of mercury 1915 and the angular deflection of light by the suns gravitation 1916. Fasterthanlight also superluminal or ftl communications and travel are the conjectural propagation of information or matter faster than the speed of light the special theory of relativity implies that only particles with zero rest mass may travel at the speed of light. Does gr general relativity allow superluminal motion. In physics, special relativity is the generally accepted and experimentally confirmed physical. Hyper fast interstellar travel within general relativity. For example, if signals could be sent faster than light, then signals could be sent into the. To show the abundance of these misconceptions we cite numerous misleading, or easily misinterpreted, statements in the literature.
Pdf the possibility of superluminal sources and their. In particular, the horizon of the field of the general relativity is just a catastrophic set. Indeed, r is the difference between the positions of m and m. And so it is actually much harder to violate causality than youd think on the surface. He writes that einsteins general theory of relativity. Obviously, there is something wrong with this conclusion, but i have some trouble finding a concrete explanation of what is exactly going on. Solid state physics and general relativity, jack sarfatti, 42002,3. Einstein supports the impossibility to send superluminal signals in a paper of 1907 1 and he bases his thesis exactly on. We show how superluminal travel can be achieved by means of the alcubierre warp drive. There are at the present moment two known solutions. Millennium relativity is a new theory in relativistic physics that replaces einsteins special and general theories of relativity. Theory of relativity and superluminal speeds springerlink. Perhaps the primary obstruction to attaining clarity on the relation between special relativity and the purported prohibition of superluminal. Much of it contains solid information about relativity written mainly for the layperson, while one important part discusses why relativity tends to forbid faster than light travel.
The proof goes by constructing a model of relativistic dynamics where ftl particles can move with arbitrary speeds. Does relativity lie at the source of quantum exoticism. This led to einsteins development of special relativity, which corrects. The possibility of superluminal sources and their doppler effect article pdf available in general relativity and gravitation 55. Handout defining einstein field equations, einstein tensor, stressenergy tensor, curvature scalar, ricci tensor, christoffel symbols, riemann curvature tensor. Hertzberg 0 1 mccullen sandora 0 1 0 medford, ma 02155, u. Proper time the time as measured by a clock on particle of superluminal particle is imaginary, which means tachyons influence something in to the past. The special theory of relativity is a coherent structure that allows for three mathematically correct types of solutions. Pdf superluminal inertial frames in special relativity. Criticism of the theory of relativity of albert einstein was mainly expressed in the early years after its publication in the early twentieth century, on scientific, pseudoscientific, philosophical, or ideological bases. It is possible that the finsler spacetimef x, y may be endowed with a catastrophic nature.
I show that according to this criterion, superluminal signaling is not prohibited. We derive the equations of motion for photons and massive. The alcubierre warp drive discovered in 1994 and the natario warp drive discovered in 2001. Ph5870, general relativity and cosmology, januarymay 2015 exercise sheet 1 special relativity. The existence of superluminal particles is consistent with relativistic.
Special relativity is said to prohibit fasterthanlight superluminal signaling, yet controversy regularly arises as to whether this or that physical phenomenon violates the prohibition. If you want to move from one point in space to another distant point in space, you are limited to locally travelling at less than the speed of light. Unsolved problems in special and general relativity. In general relativity, as you may know, the notion of an event being in the past or the future is a bit shaky since its always possible to rewrite coordinates in a way where they may be switched. Audio reading of relativity, the special and general theory, by albert einstein, dec. Nowadays this theory is often used as a prototype for other, more intricate constructions to describe forces between elementary particles or other branches of fundamental physics. The axioms for dynamics are some natural assumptions on collisions of inertial. Symmetry arguments by which 6 schwarzschild metric tensor components vanish. In classical general relativity, it is assumed that these coincide with the light cones. We use standard general relativity to illustrate and clarify several common misconceptions about the expansion of the universe. The first international conference on superluminal physics as new fields of research was hold at the university of new mexico, gallup campus, nm 87301, usa, as.
Pdf some experiments, performed at berkeley, cologne, florence, vienna, orsay and rennes led to the claim that something seems to travel. This fact is still true in general relativity, though in this case one must be somewhat more precise. Special relativity, lorentz transformation, superluminal velocity, speed of light pacs. And lately we need to find a general theory that unites all theories at. The special and the general theory, by albert einstein this ebook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. General relativity gr is einsteins theory of gravity. Introduction in a recent paper 1 two transformations as depicted below have been proposed to accommodate superluminal velocities within the frame work of special relativity. Superluminal velocities special and general relativity. If so, a particle with the superluminal speeds could be projected near the horizon of these fields, and the particle will move on the spacelike curves. Note that in these global coordinate, the photon hits the boundary also in finite coordinate time.
Say that on january 1 st you make a position measurement of galaxy x. Unsolved provblems in special and general relativity. Einsteins equations allow any spacetime if the appropriate matter source is available, but superluminal travel requires exotic sources whose energy density is negative. In this spacetime a spaceship locally at rest is surrounded by a bubble moving faster than the speed of light. You may copy it, give it away or reuse it under the terms of the project gutenberg license included with this ebook or online at. But what about a superluminal observer, one who moves faster than. Lorentz, november 19, 1919 attilio palatino original 1919 calculus of variations for general relativity. As a result, there is a general consensus among scientists that this link cannot be used to transmit useful information at a superluminal speed 1112 14. Pdf special relativity and superluminal motions erasmo. Einstein, general theory of relativity, perihelion motion of mercury einstein applied his general theory of relativity to explain three astronomical phenomena. More than ten years of research into the accepted body of experimental evidence leads to the discovery of significant flaws in the underlying foundations of.
The rotation of the plane of polarization in moving media pdf. Would superluminal influences violate the principle of. Shift, stellar aberration, and superluminal motion, are relegated to chapter 7. In reality, such experiments are very simple to explain and are in full conformance with elementary physics. Pdf a novel view of spacetime permitting fasterthanlight travel. Superluminal signaling and relativity springerlink. General relativity gr is the most beautiful physical theory ever invented. Fasterthanc signals, special relativity, and causality. It continues to be alleged that superluminal influences of any sort would be inconsistent with special relativity for the following three reasons. But special relativity sr says no influence can travel faster than light, so gravitational influences too must take time to get from m to m. The principle of relativity, superluminality and epr. So, naively, this would make particle on null geodesics go at superluminal speeds to say the least. On the infeasibility of superluminal velocities as an. In addition, the spacetime construct and superluminal realm of the.
Is it possible to send a spacecraft faster than the speed of light via wormholes or warp drive in general relativity. Various other experimental results seem to point in. I love the description of special relativity in terms of. Tachyons, particles whose speed exceeds that of light, have been hypothesized, but their existence would violate.
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