There are many approaches in quantum theory, although the idea that influences can travel backwards in time (from the future to the past) is not usually among them. However, some physicists have been studying this “retrocausality”, because it can help us solve some puzzles within the field of quantum physics. It goes without saying that this is a fringe idea , but one that deserves study.
Precisely a team of scientists from Chapman University (USA) and the Perimeter Institute for Theoretical Physics (Canada), contributes a new theory for the argument that if certain reasonable assumptions are fulfilled, then the quantum theory should be retrocausal ( where the future influences the past).
One of the strangest aspects of quantum mechanics could be explained by an also atypical idea: that ‘causation’ can go both backwards and forwards in time, allowing an effect to precede its cause. (For example, having a stomach ache today from bad food tomorrow).
Physicists Matthew S. Leifer and Matthew F. Pusey examined some basic assumptions of quantum theory in detail and decided that unless we discovered that time necessarily moved in one way, measurements made on a particle could reflect so much on the past as in the future.
Is the quantum world different when it comes to time?
The scientists used some assumptions of the physicist Huw Price, one of the main exponents of the quantum theory of retrocausality, and applied their new model to Bell’s Theorem (in honor of John Bell) that proves the connection-correlation between causally unrelated systems. ; that is, the extraordinary things that happen in quantum mechanics can never be explained by local actions.
Thus, by reformulating some basic assumptions, the researchers developed a model based on Bell’s theorem, where space was exchanged for time. In his view, unless we can show why time must always go forward, we run into some contradictions.
“There is, to my understanding, a generally accepted interpretation of quantum theory that recovers the whole theory and exploits this idea. It’s more of an idea for an interpretation at this point, so it’s normal for other physicists to be skeptical. It is up to us to embody this idea “, explain the experts.
This approach may not be attractive to us, but realistically, any explanation related to quantum theory is going to be shocking or crazy.
“Speculatively, if there is retrocausality in the universe, then it could be the case that there are certain eras, perhaps near the big bang, in which there is no definite arrow of causality, ” the experts comment.
Physicists don’t have any experiments in mind to test retrocausality, but since the idea is more of an interpretation of observations than a method of retesting, what is most needed may not be so much a test but more theoretical support.
“The type of experiments that we describe in our work provides some evidence of retrocausality, but only if they refuse to reject the other assumptions. These assumptions are always there and it is always possible to question them “, state the authors.
Reference: Matthew S. Leifer and Matthew F. Pusey. “Is a time symmetric interpretation of quantum theory possible without retrocausality?” Proceedings of The Royal Society A. DOI: 10.1098 / rspa.2016.0607
