Time travel has fascinated writers for a long time Science fiction And the scientific community. ScienceAlert was interested To a physicist, he thinks he has discovered something that makes this phenomenon possible.
Our current understanding of time depends Einstein’s theory of general relativity. This has made it possible to understand space and time as one thing: the popular “space time”. Physicists have validated Einstein’s theory with the utmost accuracy and are convinced that this is the most successful interpretation of the structure. The universe.
They also use it to find a way to time travel. So equations that are consistent with this theory have been found, but they cannot be implemented for two reasons.
First, to build a time machine, you need to be called Exotic thing, Or something with negative energy. Thanks Quantum physics, We know that this kind of material can be created in theory, but in very small and very durable quantities. We do not have conclusive evidence for this achievement.
The second reason is even more important: Contradictions of time travel Transcend logic. The most complex of these is the synchronization paradox. Here is a simple example: Imagine you are building a time machine and go back for five minutes. Then destroy this machine. But since you destroyed it five minutes before you built it, how can you use it after five minutes? After all, if you can not use it after five minutes, you can not go back in time and destroy it. In other words, the machine will only be destroyed if it is not destroyed: this scenario is very contradictory. Are you still there? Not finished yet.
Eliminate inconsistencies
In works of science fiction, these contradictions are eliminated. For example, the hero avoids changing anything that could affect the future. But in physics, a paradox is not just a phenomenon that can happen, it is a concept that points to a paradox in theory. So synchronization paradox does not only mean that time travel is dangerous for travelers, but it is simply impossible.
But then, some thought to themselves: one might refuse to eliminate the possibility of time travel due to contradictions, and instead try to eliminate contradictions. Physicist Igor Dimitrovich Novikov tried to do this The principle of self-sustainability. The past is immutable, he argues, but we can travel there: the laws of physics come together to preserve synchronization. So, in our example, even if we think of destroying the machine five minutes ago, we will not succeed.
Novikov’s hypothesis alone does not solve all the contradictions of time travel. However, Barak Shoshani, Assistant Professor University of BrockAnd his two students suggested that another theory could solve all the contradictions: it Many story.
The idea is simple: there will be many parallel timelines, and one can go back in time to the first timeline and then change events in a second but not the original. But does the universe allow multiple parallel timelines? These are only speculations at the moment, supported by Everett’s interpretation of quantum physics. “Multi-world theory”.
Thus, Barak Shoshani and his students They have been working on a theory for three years This would make parallel chronologies consistent with the general theory of relativity, which would eliminate contradictions in synchronization and take into account travel in the past.