Theoretically, according to the scientist, this may be possible, but this requires technologies that are currently underdeveloped. And also it is necessary to solve a number of problems with time paradoxes.
“first, the time machine needs exotic matter, that is, matter with negative energy. In theory, such matter can be created, but in very small quantities. But even here there is no evidence that it is impossible to obtain a sufficient amount of this matter or do without it at all, ” Shoshani explained.
The second problem with time travel has to do with paradoxes. The most famous is the paradox of consistency, when a certain event occurs that changes the past, but the change itself, in turn, prevents the event.
However, paradoxes cannot be created, since this is only a theoretical concept that indicates the failure of the theory, and not an event that can actually happen.
One attempt to eliminate paradoxes is the principle of self-consistency, proposed by cosmologist Igor Novikov, who claims that travel into the past is possible, but it cannot be changed.
However, Shoshani demonstrated that there are paradoxes that are unresolvable from the point of view of the Novikov principle, but they can be resolved if we allow the existence of many parallel timelines. The time traveler enters the past, but in a different timeline, where he can do whatever he wants, while the events in the original timeline remain unchanged.
Currently, Barak Shoshani teaches physics and astronomy, and, working with a team of students, is trying to build a theory of time travel that would fit into the data known to modern physics.