. | . |
Laboratory experiments probe the formation of stars and planets by Staff Writers Portland OR (SPX) Nov 06, 2018
The cosmos is a void dotted with stars and an ever-increasing number of newly-observed planets beyond our solar system. Yet, how these stars and planets formed out of clouds of interstellar dust and gas remains mysterious. The study of black holes provides clues that could help solve this mystery. Black holes are typically depicted as vacuum cleaners sucking up all the nearby matter and light. But in reality, clouds of dust and gas called accretion disks swirl around black holes, gradually moving closer and closer until they fall into the black holes. Researchers at Princeton Plasma Physics Laboratory helped verify one of the proposed models for how this process works. Their work, supported by NASA, the National Science Foundation, the Department of Energy, the Simons Foundation, the Institute for Advance Study and the Kavli Institute for Theoretical Physics, will be presented at the American Physical Society Division of Plasma Physics meeting in Portland, Ore. Typical objects orbiting a star, such as the planets going around our sun, continue orbiting for billions of years because their angular momentum remains unchanged, preventing them from falling inward. Such a system's angular momentum is a conserved quantity - it remains constant unless acted on by another force. If for some reason, the angular momentum of an orbiting object decreases, it can fall inward towards the star. Unlike isolated planets, orbiting matter in a denser, more crowded accretion disk can experience forces, such as friction, that cause it to lose angular momentum. Such collisions, however, are not enough to explain how quickly matter must fall inward to form planets in a reasonable time. But the magnetorotational instability, in which magnetic forces take the place of collisions, can provide an explanation. Researchers did an experiment simulating this process using a unique rotating water-filled device. Video is recorded of a water-filled red plastic ball as it moves away from the center of the device. A spring in the experiment connects the ball to a post to simulate magnetic forces. Position measurements of the ball indicate that the behavior of its angular momentum is consistent with what is expected of the magnetorotational instability. Researchers are now conducting experiments using spinning liquid metals to study what happens in accretion disks with actual magnetic forces present. The experiments confirm how strongly the magnetic field affects the metal and pave the way toward a clear understanding of the role the fields play in accretion disks. The combined results mark a significant step toward a more complete explanation of the development of heavenly bodies.
|
|
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. |