Dear all,

it is our great pleasure to announce that we are working to the next




The Time Machine Factory Conferences focus on causality and non-locality in physics, and the insurgence of situations where it appears that causality can be violated, with emphasis on their relation with time machines. There are three main objectives before this conference:

  •   provide the opportunity for debating the views of General Relativity and Quantum Mechanics on time travel
  •  revive the interest in time travel, which is not prohibited by current laws of physics
  •   contribute toward a comprehensive vision for the years to come including anticipations of potential applications


Given these three important issues and following the successful participation to the previous TM2012 and TM2015 meetings,

we are working  for the next TM2019


Scientific Rationale

The possibility of time travel, both in the past and into the future of a given observer, has left the realm of pure imagination to come into physical plausibility, starting with the seminal works by Chandrasekhar and Carter, followed by that of de Felice, Clarke, Thorne, and Novikov and several others. Time may run forward but also backwards with respect to a selected observer and under extreme space-time conditions. One of these conditions is the occurrence of a curvature singularity which is naked with respect to asymptotic regions. Curvature singularities hide themselves inside black holes so their existence is implicitly accepted once black holes are accepted as astrophysical objects. Black holes however may not necessarily form as result of gravitational collapse so naked singularities may stand as a physical reality responsible of unusual effects. Once a naked singularity forms, a general theorem by Clark and de Felice [C.J.S. Clarke and F. de Felice “Globally non causal space-times. II-naked sigularities and curvature conditions”, Gen. Rel. Gravitation 16, 139-148 (1984), and references therein] assures that a region around the singularity exists where time runs backwards with respect to null infinity. A practical example of such a situation is offered by Kerr solution where an effective cosmic time machine can be realized. Chronology can then be violated and it is consequencial that causality can be violated as well. However we shall not consider this as a real possibility being the conservation of causality a fundamental principle of physics, hence it is essential to find the way how Nature operates in order to preserve causality according to the “causality preservation principle”. A strong impetus to the deepening of such studies came also from the findings of K. S. Thorne, Novikov and collaborators, who revealed the possible presence of wormholes [Phys. Rev. D 44, 1077 (1991), Phys. Rev. Lett. 61, 1446 (1988), Int. J. Mod Phys. D4, 557 (1995)].

Despite of all this, recent developments have opened new perspectives for the “realization” of a time machine [Phys. Rev. Lett. 106, 040403 (2011)] related to the issue of quantum non- locality resulting from entanglement and, in particular, to the phenomenon of teleportation [Nature 390, 575-579 (1997), Phys. Rev. Lett. 80, 1121-1125 (1998)] and CTCs [Pienaar, J. L., Myers, C. R. & Ralph, T. C. “Quantum Fields on closed timelike curves”, Phys. Rev. A 84, 062316 (2011); Ralph, T. C., Milburn, G. J. & Downes, T., “Quantum connectivity of space-time and gravitationally induced decorrelation of entanglement” Phys. Rev. A 79, 022121 (2009); Oreshkov, O., Costa, F. & Brukner, C. “Quantum correlations with no causal order. Nat. Commun. 3, 1092 (2012)].

The topological nature of spacetime in the framework of Quantum Mechanics suggests that both causality and locality need to be analyzed at a fundamental level, also by allowing the existence of entities that are more elementary than the spatial dimensions of everyday life. Focusing on these issues would help unveiling the ultimate nature of causality, its role in fundamental physics and in the evolution of the Universe. This would allow for a better comprehension of the “direction” of large scale structure, including complex formation such as that of black holes or hierarchical structures like the Galaxy, with obvious implications on the process of mapping the Universe on local and global scales, which must remain consistent with the theories of General Relativity and Quantum Mechanics.

A complex subject like time travel cannot be dealt without a multidisciplinary vision. For these reasons, we plan to have sessions of the conference devoted to Space-Time Navigation, Faster Than Light traveling, Quantum computing, Quantistic optics/teleporting, and the Analysis of PDEs in General Relativity, both from the theoretical as well as the experimental point of view.

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