. | . |
Byzantine solar eclipse records illuminate obscure history of Earth's rotation by Staff Writers Tsukuba, Japan (SPX) Sep 16, 2022
Witnessing a total solar eclipse is an unforgettable experience and may have been even more impressive throughout history before we were able to understand and accurately predict their occurrence. But the historical records of these remarkable astronomical spectacles are more than mere curiosities-they provide invaluable information on changes in the Earth's movement. In a new study in Publications of the Astronomical Society of the Pacific, Japanese researchers combed through records from the Byzantine Empire to identify and locate total solar eclipses observed around the Eastern Mediterranean in the 4th-7th centuries CE, a period for which previously identified solar eclipse records are particularly scarce. These records are crucial for understanding the variability of the Earth's rotation throughout history. However, because the people who recorded these events in antiquity often left out key information of interest to modern astronomers, identifying the correct times, locations, and extents of historical eclipses is painstaking work. "Although original eyewitness accounts from this period have mostly been lost, quotations, translations, etc., recorded by later generations provide valuable information," co-author Assistant Professor Koji Murata of the University of Tsukuba explains. "In addition to reliable location and timing information, we needed confirmation of eclipse totality: daytime darkness to the extent that stars appeared in the sky. We were able to identify the probable times and locations of five total solar eclipses from the 4th to 7th centuries in the Eastern Mediterranean region, in 346, 418, 484, 601, and 693 CE." The key variable that this new information sheds light on is ?T, the difference between time measured according to the Earth's rotation and time independent of the Earth's rotation. Thus, variations in ?T represent variations in the actual length of a day on Earth. Taking the eclipse of July 19, 418 CE as an example, an ancient text reported a solar eclipse so complete that stars appeared in the sky, and the site of observation was identified as Constantinople. The previous ?T model for this time would have placed Constantinople outside the path of totality for this eclipse. Therefore, ?T for the 5th century CE can be adjusted based on this new information. "Our new ?T data fill a considerable gap and indicate that the ?T margin for the 5th century should be revised upward, whereas those for the 6th and 7th centuries should be revised downward" says Dr. Murata. These new data shed light on variation of the Earth's rotation on a centennial timescale, and thus help refine the study of other global phenomena throughout history, such as sea-level and ice-volume variability.
Research Report:The Variable Earth's Rotation in the 4th-7th Centuries: New ?T Constraints from Byzantine Eclipse Records
First solar eclipse of 2022 seen across South America, Antarctica Washington DC (UPI) Apr 30, 2021 The first solar eclipse of the year took place Saturday and was viewable from parts of South America and Antarctica. A live stream of the partial solar eclipse began at 3:30 p.m. EDT and ended when the sun sunk below the horizon. "If skies are clear, this eclipse is visible from South America, parts of Antarctica, and over the Pacific and Atlantic Oceans," according to TimeandDate.com. Skywatchers near the coast of Antarctica would have been able to see the solar eclipse starting ... 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. |