An international team of physicists laboratory builds a system in which the "arrow of time" pointing in the opposite direction
In our everyday experience time passes, always in one direction , that is, from the present to the future. Matter ages and decays, children grow up , adults become old and no one would be with a friend "three hours ago."
However, for decades, scientists are wondering whether the Universe "should" forcibly advance and develop in that direction only. Why not the reverse? Especially considering that in the world of subatomic particles , those from which everything and everyone is made, the laws of physics are symmetric with respect to time. Or what is the same, work the same regardless of time go forward or backward. It is to move to the macroscopic level when everything seems to "choose" to move only forward. The physicist Arthur Eddington called this situation early last century as "the arrow of time ' .
The reason why this "arrow" always points in one direction but not the other, is one of the greatest puzzles scientists of all time. And the classic answer to make things so that the arrow of time is clear from the Second Law of Thermodynamics , which states that entropy, or disorder, always increases in a closed system.
That's why, for example, that milk is easily mixed with coffee or tea, but never re-emerges clean and pure a cup of coffee with milk; or an egg, a fried once, will never again be a raw egg; or that heat always flows from the warmer to the colder object, and never the other way.
Another important reason to make things work as we are the initial conditions of the system right. And for reasons that still escape our understanding, the early universe was very hot and energy is evenly distributed everywhere. Which it is a state of low entropy in a market dominated by gravity system. Over time, indeed, the entropy of the universe has not stopped increasing, and that is what determines the direction of the arrow of time.
"Desfreír" an egg
Now, an international team of researchers led by Kaonan Micadei , a physicist at the University Federal ABC in Brazil wondered what would happen when changing the initial conditions of a closed system. That is, if the initial state of a system determines the direction of the arrow of time, would it be possible to create, here on Earth, closed systems whose initial conditions force the arrow of time to point in the opposite direction? If you answered yes, within that system fried eggs could "desfreirse" spontaneously and heat may flow from the coldest to the hottest objects.
The answer is yes. Micadei and his team have indeed achieved for the first time, to build a system like this. And indeed, in his experiment time's arrow pointing in the opposite direction , allowing researchers to see how a cold object is able to provide heat to a warm, something unthinkable in our everyday reality. The work, published in arXiv.org , opens the door to the development of a new generation of devices where time moves backward, rather than forward.
Research, of course, will not allow us to undertake a journey into the past to see dinosaurs, but yes it could tell us why our universe is "stuck" on a street in one direction.
quantum entanglement
The exotic system created in the laboratory by the investigators is a mixture of chloroform dissolved in acetone. Chloroform (CHCl3), is formed by a carbon atom, one hydrogen and three chlorine, a perfect setting to perform experiments quantum physics, which is able to manipulate the spin (a kind of internal rotation) of carbon and hydrogen nuclei through a technique called nuclear magnetic resonance.
The idea was to align the nuclei by a strong magnetic field. Physicists used radio pulses to reverse one or both Espins, and got both intertwine. Entanglement is a strange but well-known quantum process in which two particles share the same existence so that, as if two microscopic twins were, what happens to one is instantly "known" on the other, irrespective the distance separating them. Then, once intertwined, listening to the radio signals emitted by nuclei physicists were able to determine how to evolve their quantum states.
At the same time, the nuclei of atoms of carbon and hydrogen were in thermal contact , which means that the thermal energy could flow therebetween. The researchers could control the temperature of the two cores independently and heat through nuclear magnetic resonance. Under these conditions, it would be logical, as in the real world, the heat flow from the hotter to the cooler core. But Micadei and his team found just the opposite.
The key to this was, as mentioned earlier, interlacing, the phenomenon that Micadei and his colleagues exploited to create unique set of initial conditions allow, within that system, time runs backwards.
The result was the creation of a type of "motor" capable of driving the thermal energy in the opposite direction to which we are familiar. "We see -Pray the article- spontaneous flow of heat from cold to hot system".
macroscale
The finding has important implications for our understanding of the nature of time and its relation to quantum entanglement and entropy. "Our results Soble explains the thermodynamic arrow of time Micadei- could also have stimulating effects on the cosmological arrow of time". Which implies that similar to those described in the experiment processes could be responsible for the initial conditions of the universe, the system in which we live, and explain why time flows in the direction we observe.
Another significant aspect of this work, more practical in nature, is that the phenomena observed by researchers are not limited only to microscopic systems, but also work on a macroscopic scale, with a large number of molecules involved. Therefore, these results could lead to a new generation of devices into which the time run backwards , and that would be capable of conducting heat energy from cold to more hot objects.
I go to see dinosaurs, unfortunately, will still have to wait ...
Source: ABC.es
