Quirks of negative time
We see a flash (the release of a photon), the particles annihilate, but, in accordance with this diagram “from the point of view of the electron,” the positron before the act of interaction moved backward in time. “From the positron’s point of view,” the situation is completely opposite, but the interaction still occurs. The cause-and-effect relationship is not broken.
Time is an illusion
In this case, if after the end of such interaction on the “clock” the particle and antiparticle have the same amount of time, then these time periods are equal in magnitude, and antimatter exists in antitime.
We know that as time flows from the past to the future, the Universe expands (accelerating) and entropy increases. Accordingly, if antitime also arose during the Big Bang, then it should have served as the basis for antispace, in no way connected with ours. Perhaps antispace would differ from ours precisely in the reverse action of the second law of thermodynamics (entropy is constantly decreasing, and the Universe is collapsing with acceleration). In this case, the axis of antitime would disappear in those very “first three minutes”, about which the famous book by Steven Weinberg tells, and from the second Universe there would only be a flash of photons – the result of annihilation. But, if this did not happen, and the anti-universe in its anti-time and with other anti-dimensions exists side by side with ours, then its influence could affect ours, for example, in the form of wave effects and quantum entanglement.
It also cannot be ruled out that time is completely emergent and even illusory. This concept is developed by the American physicist Sean Carroll in his books “Eternity” And “Universe“— Here a chapter from the second book has been posted, which outlines the connection between the passage of time and the increase in entropy.
An even more radical point of view is expressed by an Italian-American physicist Carlo Rovelliexploring quantum entanglement, cause-and-effect relationships, popularizing the idea of time loops, and also trying to formulate the foundations of quantum gravity. Rovelli, in principle, is not inclined to include time in calculations as a significant variable, but prefers to work with discrete quanta. Rovelli considers time one of the manifestations of entropy and argues that “time does not exist where there is no heat” In this case, the absence or reverse course of time could be recorded during the interactions of elementary particles or individual atoms.
When time fails
Perhaps this thesis can be confirmed or refuted if such interactions are found at the subatomic level that will measurably change under negative time conditions. Such experiments would explain the almost complete absence of antimatter in nature. If some forces reversed time at the level of individual particles, then these particles would have a constant electric dipole moment (EDM). In various experiments they tried to detect the electric dipole moment in neutrons, atoms and molecules, but so far such searches have not been crowned with success.
EDM searches often use high-precision atomic clocks placed in a controlled magnetic field (uniform in time and stable in time). In an electric field, such a clock, which has a constant electric dipole moment, should run a little faster or a little slower than the control clock. The electric dipole moment of atoms arises mainly due to interatomic forces. As a rule, such experiments are carried out on atoms of radium and mercury, since the limits of “normal” interatomic interactions of this kind are well known for them. They are currently most accurately calculated for the mercury-199 atom. Researchers at the University of Washington in Seattle have used it to build an atomic clock that moves one second every 40,000 years. Such clocks have not yet shown deviations in the passage of time, so the search continues for an isotope that would be even less sensitive to external interference than mercury-199. In 2019, a collaboration from the University of Michigan, the Massachusetts Institute of Technology and Argonne National Laboratory (the collaboration is led by Professor Jaideep Singh from the University of Michigan, working at the famous Factory of rare isotopes). Scientists are trying to repeat the experiment, using instead of mercury the rare isotope radium-225, which has a half-life of about 14.9 days. The core of this element has an elongated pear-shaped shape, therefore it increases the sensitivity of the above-described atomic clocks by another thousand times compared to the mercury model. The protactinium-229 nucleus also has a similar shape, with a half-life of 1.4 days—potentially its sensitivity could be even higher than that of radium. However, by 2024, the first signs of time reversal were detected not at the level of atoms, but at the level of photons, and this was achieved by a team led by Daniela Angullo from the University of Toronto. According to the study, laid out on the website arxiv.org on September 5 as a preprint, it can be assumed that photons can spend negative time in a cloud of cooled gas atoms, although non-zero (positive) time is spent on the experiment itself.
The idea for this experiment arose in 2017, when University of Toronto employees Ephraim Steinberg and his graduate student Josiah Sinclair studied excitation of atomstrying to better understand the principles of interaction between light and matter. When photons penetrate a certain medium, electrons in the atoms of this medium receive additional energy and move to higher energy levels in their atoms. Returning to the ground state again, the atoms emit excess energy also in the form of photons, and therefore a delay can be noticed in the passage of light through such a medium.
Sinclair wanted to measure this “group” delay as accurately as possible, and to try to do it in a medium so rarefied that a photon, theoretically, could pass through it without hitting a single atom. For this purpose, after three years, an installation was prepared that made it possible to penetrate a cloud of rubidium atoms, cooled almost to absolute zero, with photons, after which it was possible to measure the degree of excitation of these atoms. Experiment right away led to strange results: In some cases, the photons clearly passed through the medium without hitting a single atom, but the rubidium atom appeared excited. Moreover, in cases where photons were absorbed by rubidium atoms, the atoms re-emitted them almost instantly, while still clearly being in an excited state. In general, photons were leaving atoms much faster than they should have been, so Canadian scientists, together with Australian colleague Howard Wiseman from Griffiths University in Queensland, developed explanationaccording to which photons could leave atoms earlier than they entered them – this is precisely the conclusion that can be drawn from the fact that atoms linger in an excited state longer than they should. A more traditional explanation for this phenomenon may be related to the wave-particle duality of the photon. The behavior of a photon is described by a wave function, and the photon is a fuzzy entity rather than a point in space. Nevertheless, it would be interesting to wait for a detailed analysis or refutation of this hypothesis about the manifestation of the negativity of time at the level of elementary particles. But if the photon spends less time in the atom than it takes for the atom to re-emit the photon and move to a lower energy level, then to the observer the situation looks as if the photon spends a negative amount of time in the atom.
Contrary to usual, I will leave this article without a conclusion and, perhaps, I will add one after studying the comments of my readers.
