Im if, for every neighborhood o of p, there exists a point t 0 ai such that. Csc165 is the most important course youll ever take. Experimental simulation of closed timelike curves core. Van stockum, godel and the discovery of the closed timelike curve in the introduction of the article this is said about godels solution to the equations of gr. The feat should be possible based on einsteins theory of general relativity, which describes gravity as the warping of spacetime by energy and matter. Im such that there are distinct points s, s0 ai with s. Philosophy of cosmology notes stanford encyclopedia of.
Article pdf available december 2014 with 282 reads. First, the topology of every past and future distinguishing spacetime is determined by its causal structure. May 11, 2010 in special and general relativity, motion in spacetime is classified as timelike, spacelike, or lightlike which is sometimes called null. A metric is an abstract thing too, to do with your measurements of distance and time, typically made using the motion of light. Closed timelike curves the source of time travel speculation lies in the fact that our best physical theories seem to contain no prohibitions on traveling backward through time. As legitimate solutions to einsteins eld equations, they allow for time travel, which instinctively seems paradoxical. Quantumstate cloning in the presence of a closed timelike curve d.
Pdf in general relativity, closed timelike curves can break causality with. The class of continuous timelike curves determines the. Closed timelike curves are among the most controversial features of. Mann 4, 1 centre for quantum information processing. Jul 25, 2012 quantumstate cloning in the presence of a closed timelike curve d.
Time travel simulation resolves grandfather paradox. We say a closed timelike curve is kinked if smoothness indeed fails at this point. Surprisingly, such a timelike curve may fulfil the condition, which means that the curve is closed in spacetime. Time, time travel, and closed timelike curves page 3. Jun 19, 2014 closed timelike curves are among the most controversial features of modern physics. Experimental simulation of closed timelike curves martin ringbauer 1,2, matthew a. Unknown state cloning ahn, myers, ralph and mann, pra 88, 022332 20.
Studies in history and philosophy of modern physics. The set iq is the set of all points in m from which a continuous, everywhere futuredirected timelike curve can reach q. In general relativity, closed timelike curves can break causality with remarkable and unsettling consequences. As legitimate solutions to einsteins field equations, they allow for time travel, which instinctively seems paradoxical. If it was the worldline of an object, it would describe a case where the object revisited the same location in the past and took over the worldline again from its own past self. Novikov intended it to solve the problem of paradoxes in time travel, which is theoretically permitted in certain solutions of general relativity that contain.
Sep 02, 2014 closed timelike curves the source of time travel speculation lies in the fact that our best physical theories seem to contain no prohibitions on traveling backward through time. In quantum physics, the distinction between cause and effect is not made at the most fundamental level and so timesymmetric systems can be viewed as causal or retrocausal. In a closed timelike curve, the worldline of an object through spacetime follows a curious path where it eventually returns to the exact same coordinates in space and time that it was at previously. You cant actually see any lightcones or worldlines. Received 7 nov 20 accepted 16 may 2014 published 19 jun.
Im if, for every neighborhood o of p, there exists a point t 0 ai such that t. Retrocausality, or backwards causation, is a concept of cause and effect in which an effect precedes its cause in time and so a later event affects an earlier one. The title assertion is proven, and two corollaries are established. At the classical level, they induce causal paradoxes disturbing enough to. Doctor who meets professor heisenberg 20 june 2014 spacetime structure exhibiting closed paths in space horizontal and time vertical. Closed timelike geodesics in a gas of cosmic strings iopscience. However, in the quantum regime these paradoxes can be resolved, leaving closed timelike curves consistent with relativity. Computability theory of closed timelike curves scott aaronson mohammad bavariany giulio gueltriniz abstract we ask, and answer, the question of whats computable by turing machines equipped with time travel into the past. Superposition and grover algorithm in the presence of a closed timelike curve ki hyuk yee u. School of mathematics and physics, university of queensland. Replicating the benefits of deutschian closed timelike curves. The dctc condition has originally been proposed by david deutsch as a condition on states of a quantum communication network that contains backward timesteps in some of its branches.
Toy models for quantum evolution in the presence of closed timelike curves have gained attention in the recent literature due to the strange effects they pre. Dec 07, 2017 this would create a closed timelike curve, or ctc, a loop that could be traversed to travel back in time. A closed timelike curve wouldnt actually look like anything because its an abstract thing. Why csc180 is the the most important course youll ever take. Closed timelike curve how is closed timelike curve. Pdf replicating the benefits of closed timelike curves without. Closed timelike curves make quantum and classical computing equivalent, proceedings of the royal society a 465.
Closed timelike curves are among the most controversial features of modern physics. Introductionpath algebrasclassical causal theoryquantum causal theorypa in qctreferences notation and conventions distinguished terms are blue. Ctcindeterminism is close to the epistemological indeterminism we know from statistical physics, while the fixedness typical of ctcdeterminism is pervasive in. Mulder and dennis dieks abstract notoriously, the einstein equations of general relativity have so lutions in which closed timelike curves ctcs occur. Pdf experimental simulation of closed timelike curves. Information and translations of closed timelike curve in the most comprehensive dictionary definitions resource on the web. Quantum state cloning in the presence of a closed timelike. Replicating the benefits of deutschian closed timelike. Closed timelike smooth curves in the general theory of relativity. A point pam is a future endpoint of a futuredirected causal curve. Quantum interactions with closed timelike curves and superluminal. Pdf closed timelike curves and the second law of thermodynamics. However, in the quantum regime these paradoxes can be resolved leaving closed timelike curves consistent with relativity.
The metric admits circular closed timelike curves, which appear beyond the null curve, and these timelike curves are linearly stable under linear perturbations. However, the novikov selfconsistency principle is intended to go beyond just the statement that history must be consistent, making the additional nontrivial assumption that the universe obeys the same local laws of physics in situations involving time travel that it does in regions of spacetime that lack closed timelike curves. Degtyarev, the alexander module of a trigonal curve, revista mathematica iberoamericana, 30, 2564 2014 pdf. Pdf closed timelike curves are among the most controversial. Sep 25, 2015 a closed timelike curve is a timelike curve that forms a closed loop rather than a line that stretches off indefinitely into the past and future. A closed timelike curve is a timelike curve that forms a closed loop rather than a line that stretches off indefinitely into the past and future. Quantum interactions with closed timelike curves and superluminal signaling. A newly published study shows that it is possible to clone quantum information from the past, allowing for a particle, or a time traveler, to make multiple loops back in time. Study shows that it is possible to clone quantum information. Newest closedtimelikecurve questions physics stack exchange. Considering a circular timelike curve in the plane zconstant, this equation takes the form.
As legitimate solutions to einstein\u27s field equations, they allow for time travel, which instinctively seems paradoxical. A closed timelike curve maygs p gs fail to be smooth at this initial terminal point gs since the initial and terminal tangent vectors to g will generally be different there malament 1985, 777. Its intriguing that youve got general relativity predicting these paradoxes, but then you consider them in quantum mechanical terms and the paradoxes go away, says university of queensland physicist tim ralph. Mulder and dennis dieks abstract notoriously, the einstein equations of general relativity have solutions in which closed timelike curves ctcs occur.
Experimental simulation of closed timelike curves nature. If it was the worldline of an object, it would describe a case where the object revisited the same location in the. How to create a closed timelike curve soul physics. Timelike curves of limited acceleration in general relativity. In mathematical physics, a closed timelike curve ctc is a world line in a lorentzian manifold, of a material particle in spacetime that is closed, returning to its starting point. Quantum state cloning in the presence of a closed timelike curve. In mathematical physics, a closed timelike curve is a world line in a lorentzian manifold, of a material particle in spacetime that is closed, returning to its starting. Science fiction, or speculative fiction if you prefer. Manchak 2009 establishes the generality of malaments. These three types of motion represent different things.
As legitimate solutions to einsteins field equations, they allow for time travel, which instinctively seems. In special and general relativity, motion in spacetime is classified as timelike, spacelike, or lightlike which is sometimes called null. Department of physics and astronomy 447 nicholson hall, tower drive. Volume 10 2014 progress in physics issue 4 october concluding remarks closed timelike curves turn out to exist in many other exact solutions to einsteins. A type d nonvacuum spacetime with causality violating. Time, time travel, and closed timelike curves page 3 the. A simple result, restricting the behavior of a timelike curve under limitations on its integrated acceleration, is obtained and discussed. For example, a closed timelike curve could exist in a region outside the copies of the causal pasts, violating global hyperbolicity. Irreversible physics along closed timelike curves philsciarchive. A closed timelike curve sometimes abbreviated ctc is a theoretical solution to the general field equations of the theory of general relativity. Determinism and indeterminism on closed timelike curves. Experimental simulation of closed timelike curves uq espace.
It has been argued that this is an analogue for quantum processes in the presence of closed timelike curves ctcs. Or one could do a few steps of a computation, then \set back the clock and do a few more steps, and so on, reusing the same time interval as often as one liked. Quantum physics, fields and closed timelike curves. Ralph 2 closed timelike curves are among the most controversial features of modern physics. Superposition and grover algorithm in the presence of a. Asimov, bradbury, clarke, dick, heinlein and other sf books. Introductionpath algebrasclassical causal theoryquantum causal theorypa in qctreferences referencesii. Jul 25, 2017 the dctc condition has originally been proposed by david deutsch as a condition on states of a quantum communication network that contains backward timesteps in some of its branches. The cauchy horizon is generated by closed null geodesics. Second, in every spacetime the path topology of hawking, king, and mccarthy codes topological, differential, and conformal structure. May 28, 20 the basic idea of a ctc is fairly simple.
Im such that there are distinct points s, s0 ai with. Popular television shows such as doctor who have brought the idea of time travel into the vernacular of popular culture. Lanczos in 1924 5, and later rediscovered underanother form by w. According to wilde, deutsch suggested in his late 20th century paper that it should be possible to violate the fundamental nocloning theorem of quantum mechanics. Closed timelike curve register polynomial size circuit s. For a spacetime which admits a closed timelike smooth curve it is estimated that. On these curves time loops back onto itself, which has exotic consequences. The novikov selfconsistency principle, also known as the novikov selfconsistency conjecture and larry nivens law of conservation of history, is a principle developed by russian physicist igor dmitriyevich novikov in the mid1980s. Newest closedtimelikecurve questions physics stack. See malament 1977 and manchak 2009 for further discussion.
737 94 110 1360 1295 907 932 703 6 1249 326 171 1130 111 197 276 959 1494 1468 102 1518 960 1323 315 1470 1232 619 1113 249 676 501 341 746 321 992 1456 1143 146 76 984 927 907 986 494 157 12 1368 367 336 400 34