Past. The present. Future. For physics, they are all the same. However, for you, me, and everyone else, time moves in only one direction: from expectations to experiences and memories. This linearity is called the time axis (sometimes called the arrow of time), and some physicists believe that it moves in one direction only for humans and other species that are able to perceive its movement only in this way.
The question of the time axis has been sorted out by scientists for quite some time. And its main aspect is not whether time exists at all, but in what direction this time is actually moving. Many physicists believe that time manifests itself when a sufficient number of tiny elementary particles, individually controlled by rather strange laws of quantum mechanics, begin to interact with each other and exhibit behavior that can already be explained using the classical laws of physics. However, in the pages of the latest issue of the German journal Annalen der physic (the same journal on the pages of which Einstein's series of articles on general and special theories of relativity were published), two scientists claim that gravity is not strong enough toso that absolutely all objects in the Universe follow the principle of the direction of the time axis past - present - future. Instead, scientists believe that the time axis itself is created by outside observers.
One of the main modern problems in physics is the adaptation of quantum mechanics to classical ones. In quantum mechanics, particles can have superpositions. For example, one electron can exist in two places at the same time and it is impossible to find out which one is until you make an observation. Here the main aspect is probability. Finding out the location can only be experimentally.
However, the rules change dramatically if electrons begin to interact with other objects, for example, with air atoms, or as part of dust particles and, in general, all types of matter. Here the rules of classical mechanics come into force, and gravity becomes the most important factor in the interaction of these particles.
"The position of the electron, each atom, is controlled by probability," says Yasunori Nomura, a physicist at the University of California, Berkeley.
But as soon as they begin to interact with larger particles or become part of an object, such as a baseball, then all of these individual probabilities of their position are mixed, and the chances of all these electrons in superposition are reduced. Therefore, you will never see how the same baseball can be in two places at once - in the catcher's glove and flying out of the playing field.
The moment when the physics of elementary particles collides (merges) with classical mechanics is called decoherence. From the point of view of physics, this happens when the direction of the flow of time becomes mathematically significant. Many physicists believe that the time axis is exactly what comes from decoherence.
The most famous theory explaining the decoherence principle is the Wheeler - DeWitt equation. The theory appeared in 1965, when physicist John Wheeler had to stay for a long time at the airport in North Carolina (USA). To kill time, he asked his colleague Bruce DeWitt to meet him. The two scientists met and, as is usually the case, began to talk about various theories and "play with numbers." At some point, both came up with an equation that Wheeler thought (since DeWitt was more skeptical about the matter) is a seam between quantum and classical mechanics.
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The theory turned out to be imperfect. However, it turned out to be very important for physics. Many scientists have agreed that it is an important tool in understanding all the oddities of the process of decoherence and so-called quantum gravity.
Despite the fact that the time variable is not included in the equation (in physics, time is measured by the transition of one object from one place to another or a change in its state), it creates the basis for linking everything in the universe.
However, in a new scientific article, two scientists say that in the Wheeler-DeWitt equation, gravity affects time too slowly to be accepted as a universal time axis.
“If you look at the examples and do the calculations, it turns out that the equation does not explain how the directionality of time appears,” says Robert Lanza, biologist, polymath and co-author of the article. (Lanza is a proponent of biocentrism - the theory that biological life creates the reality around us, time and the universe - that is, life creates the universe, and not vice versa).
The scientist explains this by the fact that quantum particles must retain the properties of their superpositions until they are captured by gravity. If gravity turns out to be too weak to maintain the interaction between particles during their decoherence into something larger, then it will be unable to make the particles move in the same direction in any scenario.
If mathematics cannot solve this question, then the answer may lie in the observer. That is, in ourselves. Time moves exactly the way it moves, because we humans are initially biologically, neurologically and philosophically “programmed” to perceive time in this way. It's like Schrödinger's cat at the macro level. It is possible that the far end of the universe is moving from the future to the past, and not vice versa. It is quite possible that when looking through telescopes, time passes from this state and acquires a more understandable direction of "past - future" for us.
"In his work on the theory of relativity, Einstein showed that time is relative to the observer," Lanza says.
"Our work develops this idea and says that in fact the observer himself creates time."
Of course, this theory cannot be called new. The Italian physicist Carlo Rovelli published an article about this in the largest open scientific web library ArXiv.org last year. There are also enough contradictions in it. For example, Nomura says that it is not yet clear how to find out if the concept of "observer time" is real.
"The answer will depend on whether the concept (concept) of time can be defined mathematically without including observers in the system," says the scientist.
The authors of the article argue that there is no way to exclude the observer from any equation, since these equations are deduced and analyzed by humans by default.
Nomura also notes that the authors of the theories did not take into account the fact that the entire universe exists in the so-called transitional state of "space-time".
"When we talk about space-time, we are talking about an already decohere system."
Of course, Namura did not say that other scientists are completely wrong and that physics is still an incomplete, incomplete and incomplete science (and, interestingly, it is difficult to argue with this), but he noted that he completely disagrees with the conclusions which were made by these scientists. In his opinion, like time itself, all interpretations in physics are relative.
NIKOLAY KHIZHNYAK