. | . |
New measurements of the solar spectrum verify Einstein's theory of General Relativity by Staff Writers Washington DC (SPX) Oct 09, 2020
This work, which verifies one of the predictions of Einstein's General Relativity, is to be published in the journal Astronomy and Astrophysics. The General Theory of Relativity, published by Albert Einstein between 1911 and 1916, introduced a new concept of space and time, by showing that massive objects cause a distortion in space-time which is felt as gravity. In this way, Einstein's theory predicts, for example, that light travels in curved paths near massive objects, and one consequence is the observation of the Einstein Cross, four different images of a distant galaxy which lies behind a nearer massive object, and whose light is distorted by it. Other well known effects of General Relativity are the observed gradual change in Mercury's orbit due to space-time curvature around the "massive" Sun, or the gravitational redshift, the displacement to the red of lines in the spectrum of the Sun due to its gravitational field. The gravitational redshift is an important effect for satellite navigation systems such as GPS, which would not work if General Relativity was not put into the equations. This effect depends on the mass and the radius of an astronomical object, so that even though it is bigger for the Sun than for the Earth, it is still difficult to measure in the solar spectrum. In 1920, Einstein wrote: "For the Sun, the theoretical redshift predicted is approximately two millionths of the wavelength. Whether this effect really exists is an open question, and astronomers are currently working hard to resolve it. For the Sun, its existence is difficult to judge because the effect is so small". To measure it, the scientists have used observations of the solar spectrum reflected from the Moon, obtained with the HARPS (High Accuracy Radial-velocity Planet Searcher) instrument using the new technology of the laser frequency comb. "Combining the precision of the HARPS instrument with the laser frequency comb, we have been able to measure with high accuracy the position of the iron lines in the solar spectrum", explains Jonay Gonzalez Hernandez, a Ramon y Cajal researcher at the IAC and first author of the article. "This has enabled us to verify one of the predictions of Einstein's Theory of General Relativity, the gravitational redshift, to a precision of just a few metres per second". "New measurements with the laser frequency comb attached to the ESPRESSO spectrograph, on the 8.2 m VLT telescopes, would allow us to improve these measurements", adds Rafael Rebolo, a researcher and the Director of the IAC and a coauthor of the article.
Research Report: "The solar gravitational redshift from HARPS-LFC Moon spectra. A test of the General Theory of Relativity"
Radio astronomers join moon mission to explore early universe Charlottesville VA (SPX) Sep 23, 2020 The National Radio Astronomy Observatory (NRAO) has joined a new NASA space mission to the far side of the Moon to investigate when the first stars began to form in the early universe. The universe was dark and foggy during its "dark ages," just 380,000 years after the Big Bang. There were no light-producing structures yet like stars and galaxies, only large clouds of hydrogen gas. As the universe expanded and started to cool down, gravity drove the formation of the stars and black holes, which en ... 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. |