Winston
Lorenzo von Matterhorn
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Experiment shows that arrow of time is a relative concept, not an absolute one
https://phys.org/news/2017-12-arrow-relative-concept-absolute.html
(Phys.org)An international team of researchers has conducted an experiment that shows that the arrow of time is a relative concept, not an absolute one. In a paper uploaded to the arXiv server, the team describe their experiment and its outcome, and also explain why their findings do not violate the second law of thermodynamics.
The second law of thermodynamics says that entropy, or disorder, tends to increase over time, which is why everything in the world around us appears to unfold forward in time. But it also explains why hot tea grows cold rather than hot. In this new effort, the researchers found an exception to this rule that works in a way that doesn't violate the rules of physics as they have been defined.
The idea of entangled particles has been in the news a lot lately as researchers around the world attempt to use it for various purposesbut there is another lesser-known property of particles that is similar in nature, but slightly different. It is when particles become correlated, which means they become linked in ways that do not happen in the larger world. Like entanglement, correlated particles share information, though it is not as strong of a bond. In this new experiment, the researchers used this property to change the direction of the arrow of time.
The experiment consisted of changing the temperature of the nuclei in two of the atoms that exist in a molecule of trichloromethanehydrogen and carbonsuch that it was higher for the hydrogen nucleus than for the carbon nucleus, and then watching which way the heat flowed. The group found that when the nuclei of the two atoms were uncorrelated, heat flowed as expected, from the hotter hydrogen nucleus to the colder carbon nucleus. But when the two were correlated, the opposite occurredheat flowed backward relative to what is normally observed. The hot nucleus grew hotter while the cold nucleus grew colder. This observation did not violate the second law of thermodynamics, the group explains, because the second law assumes there are no correlations between particles.
https://phys.org/news/2017-12-arrow-relative-concept-absolute.html
(Phys.org)An international team of researchers has conducted an experiment that shows that the arrow of time is a relative concept, not an absolute one. In a paper uploaded to the arXiv server, the team describe their experiment and its outcome, and also explain why their findings do not violate the second law of thermodynamics.
The second law of thermodynamics says that entropy, or disorder, tends to increase over time, which is why everything in the world around us appears to unfold forward in time. But it also explains why hot tea grows cold rather than hot. In this new effort, the researchers found an exception to this rule that works in a way that doesn't violate the rules of physics as they have been defined.
The idea of entangled particles has been in the news a lot lately as researchers around the world attempt to use it for various purposesbut there is another lesser-known property of particles that is similar in nature, but slightly different. It is when particles become correlated, which means they become linked in ways that do not happen in the larger world. Like entanglement, correlated particles share information, though it is not as strong of a bond. In this new experiment, the researchers used this property to change the direction of the arrow of time.
The experiment consisted of changing the temperature of the nuclei in two of the atoms that exist in a molecule of trichloromethanehydrogen and carbonsuch that it was higher for the hydrogen nucleus than for the carbon nucleus, and then watching which way the heat flowed. The group found that when the nuclei of the two atoms were uncorrelated, heat flowed as expected, from the hotter hydrogen nucleus to the colder carbon nucleus. But when the two were correlated, the opposite occurredheat flowed backward relative to what is normally observed. The hot nucleus grew hotter while the cold nucleus grew colder. This observation did not violate the second law of thermodynamics, the group explains, because the second law assumes there are no correlations between particles.
