Theoretical physicists from the University of Cambridge have prepared an experimental model in which they simulate time travel into the past with so-called entangled particles, using quantum phenomena, an unsolvable problem according to the Standard Model. The interesting experiment is another theoretical proof of time travel.
Scientists say time travel is possible, but how?
The question of whether it is possible to go back in time was first raised more seriously in connection with Albert Einstein’s theory of general relativity published in 1916. Einstein’s theory does not rule out that time can only move in one direction in curved space-time.
In the theory of general relativity, Einstein unified space and time into a four-dimensional coordinate system, adding the three spatial coordinates with the fourth time coordinate. Since Einstein traced gravity to the curvature of space-time, from which the model of a finite but infinite (expanding) universe was also born; In this model, time can – theoretically – return to itself, it can also move backwards, that is, time travel is possible.
In 1949, one of Einstein’s collaborators, the Austrian mathematician Kurt Gödel, came up with an entirely new solution to the field equations in the theory of general relativity,
Which – under certain conditions – enables time travel.
In Godel’s mathematical induction, time and space can be curved together into a contour. With this discovery, Gödel found the first “closed time-like curve” in Einstein’s field equations, the CTC (closed time-like curve). Although Albert Einstein admired Gödel’s extrapolation, he was skeptical of his colleague’s conclusion, because he did not see it as proven by experimental data that time travel was possible.
In 1963, three American scientists, Ezra Newman, Theodor Onti, and Luis Tamburrino, discovered a new solution to Einstein’s equations, which – like Gödel’s extrapolation – allowed time travel. Not only did the American theoretical physicist and Nobel Prize winner Kip Throne and his colleagues confirm in a study published in 1988, based on solutions of Einstein’s field equations, that time travel is possible, but rather that it is very possible under certain circumstances.
What is the evidence for time travel, if any?
Despite all this, there is still disagreement among theoretical physicists about whether elementary particles can travel back in time. What is indisputable is the fact that in quantum physics, that is, in the world of particles, the laws prevailing in the macro world lose their validity, which also applies to the theory of time travel. One of the most exciting chapters in Einstein’s theory is so-called quantum entanglement, which Albert Einstein called the eerie effect at a distance.
Because he encountered a strange phenomenon that was incomprehensible even to him.
The essence of quantum entanglement is that if two elementary particles are created by the same event, they remain connected, even if they are very far apart. If something happens to one of them, no matter how far apart they are, their partner will react. In the language of theoretical physics, the two particles have a non-local or non-fixed relationship with each other, as they form part of the same quantum state, and thus their properties are intertwined.
What is truly surprising is that this entanglement persists even when…
If the particles that make up the pair are hundreds of thousands or even millions of light-years away from each other.
This phenomenon, the eerie remote effect, is also the basis of a time travel simulation recently developed by theoretical physicists at the University of Cambridge, which sheds new light on the theory of time travel.
We can go back in time, but we cannot change the past
the Physical review letter A study published in a scientific journal has developed a revolutionary new thought experiment for the journey of entangled particles into the past. In the investigation by Cambridge Hitachi Laboratory researchers, only one pair of entangled particles participated in the experiment itself, while the other was manipulated in such a way that the outcome of the experiment could then be changed. David Arvidsson Shakur, a scientist at the lab, explains the essence of their experiment with a live example.
Suppose we want to send a gift to someone, and we send it today so that you can receive the package on the third day. However, the next day – after we have already given in – we learn about the recipient’s desire. Respecting the chronology, even if we know what kind of gift the recipient wants, once the package is sent with the other gift, we will not have the opportunity to correct it. Related to this, let’s imagine that knowing the order received on the second day, we can change the shipment sent the previous day.
In the thought experiment conducted by the researchers, it was possible to change a previous decision in order to produce a result that was later decided upon. Returning to the world of quantum mechanics, the experiment looked like a given photon should reach a sensor if it had the right properties. When the researchers discovered what those properties were, they were able to manipulate the entangled photon pair in a way that changed the original photon.
“Our proposal is not a time machine, but a headlong dive into the basic principles of quantum mechanics. This simulation does not allow us to change the past, but it is suitable for obtaining a better future result by correcting yesterday’s problems today – the results of the thought experiment were evaluated by David Arvidsson Shakur, a scientist specializing in Cambridge Hitachi Laboratory.
