. | . |
Einstein finally warms up to quantum mechanics? by Staff Writers Kyoto, Japan (SPX) Dec 10, 2021
Einstein was no stranger to mathematical challenges. He struggled to define energy in a way that acknowledged both the law of energy conservation and covariance, which is general relativity's fundamental feature where physical laws are the same for all observers. A research team at Kyoto University's Yukawa Institute for Theoretical Physics has now proposed a novel approach to this longstanding problem by defining energy to incorporate the concept of entropy. Although a great deal of effort has gone into reconciling the elegance of general relativity with quantum mechanics, team member Shuichi Yokoyama says, "The solution is shockingly intuitive." Einstein's field equations describe how matter and energy shape spacetime and how in turn the structure of spacetime moves matter and energy. Solving this set of equations, however, is notoriously difficult, such as with pinning down the behavior of a charge associated with an energy-momentum tensor, the troublesome factor that describes mass and energy. The research team has observed that the conservation of charge resembles entropy, which can be described as a measure of the number of different ways of arranging parts of a system. And there's the rub: conserved entropy defies this standard definition. The existence of this conserved quantity contradicts a principle in basic physics known as Noether's theorem, in which conservation of any quantity generally arises because of some kind of symmetry in a system. Surprised that other researchers have not already applied this new definition of the energy-momentum tensor, another team member, Sinya Aoki, adds that he is "also intrigued that in general curved spacetime, a conserved quantity can be defined even without symmetry." In fact, the team has also applied this novel approach to observe a variety of cosmic phenomena, such as the expansion of the universe and black holes. While the calculations correspond well with the currently accepted behavior of entropy for a Schwarzschild black hole, the equations show that entropy density is concentrated at the singularity in the center of the black hole, a region where spacetime becomes poorly defined. The authors hope that their research will spur deeper discussion among many scientists not only in gravity theory but also in basic physics.
Research Report: "Charge conservation, entropy current and gravitation"
Record-breaking simulations of large-scale structure formation in the universe Tsukuba, Japan (SPX) Dec 02, 2021 Current simulations of cosmic structure formation do not accurately reproduce the properties of ghost-like particles called neutrinos that have been present in the Universe since its beginning. But now, a research team from Japan has devised an approach that solves this problem. In a study published this month in SC '21: Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis, researchers at the University of Tsukuba, Kyoto University, and the U ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |