What is the quantum time travel theory

Independent magazine for business and education

© Bilderbox.com

An international team of quantum researchers from the Austrian Academy of Sciences has closed a gap in the physics theory on time travel, paving the way for new investigations into time-traveling objects.

(red / czaak) As early as 1949, Kurt Gödel answered whether an object could collide with a more recent version of itself using Einstein's general theory of relativity. According to the theory, a universe is possible where points are directly causally connected to one's own past via a time curve.

Such points can also interact with an older version of themselves through this curve. Since Gödel's discovery, it is still uncertain whether a journey through time is conclusive and possible not only in theory but also in the real world.

The journey back to your own grandfather
Physicists refuted the first logical objection to the fundamental possibility of time travel back in the 1990s, symbolized with the so-called grandfather's paradox. This means that one cannot travel into the past for that reason alone, since in this case one could kill one's own grandfather - and thus would have prevented one's own existence.

Physicists resolved this contradiction by assuming a coherent universe. Here it is not even possible to kill your own grandfather, since every act during a journey back in time would have long been part of the grandfather's life story anyway. The nature of this temporal-causal relationship remained open.

Infinite number of logically coherent time curves
The physicists then determined an infinite number of logically coherent time curves that connect a clear initial state, the undisputed grandfather, with a clear final state, the existing grandson. So far, it has only been possible to investigate which time curve is realized between these two points in our physical world with the help of quantum physics - which in turn resulted in numerous new questions.

An international research team of scientists from the Università della Svizzera Italiana in Lugano, Switzerland, the Australian University of Queensland and the Institute for Quantum Optics and Quantum Information Vienna of the Austrian Academy of Sciences (ÖAW) has now found a possible way out and a surprising finding using methods from classical theoretical physics .

Classical physics also applies in local areas
“We assumed that classical physics also applies in local areas,” explains OeAW quantum researcher Ämin Baumeler. “On this basis, we were able to determine that the questions associated with time travel can also be explained entirely without quantum physics and that time travel does not contradict the local laws of physics in any way,” emphasizes Baumeler.

"The successful recourse to classical theoretical physics can be seen as a clear advance in the study of time travel, according to the Austrian Academy of Sciences in a broadcast on the study, which was also published in the renowned specialist journal" Classical and Quantum Gravity ". The researchers are now hoping for new possibilities in order to be able to examine the dynamics of time-traveling objects even better.

red / czaak, Economy edition web article, 04.11.2019