{"id":29439,"date":"2023-06-29T02:00:31","date_gmt":"2023-06-29T00:00:31","guid":{"rendered":"https:\/\/www.sciencefocus.com\/?p=147447"},"modified":"2023-06-29T03:38:25","modified_gmt":"2023-06-29T01:38:25","slug":"groundbreaking-gravitational-wave-discovery-could-unlock-our-universes-deepest-mysteries","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/rss_feed\/groundbreaking-gravitational-wave-discovery-could-unlock-our-universes-deepest-mysteries\/","title":{"rendered":"Groundbreaking gravitational wave discovery could unlock our Universe\u2019s deepest mysteries"},"content":{"rendered":"

The results are the first evidence of the gravitational wave background, a hum of spacetime ripples that pervades the Universe. <\/p>

By Jason Goodyer\n \t\t<\/p>

Published: Thursday, 29 June 2023 at 12:00 am<\/p>

\n\n

After 15 years of painstaking observations, an international team of researchers has listened in on the ripples of gravitational waves that perpetually course throughout the Universe<\/a> for the first time.<\/p>\n

The discovery of the long-theorised \u2018gravitational wave background\u2019 could lead to answers to some of cosmology\u2019s longest-standing questions, from the fate of colliding supermassive black holes<\/a> to the frequency of galaxy mergers and maybe even the birth of the Universe.<\/p>\n

The newly detected gravitational waves were observed by a team at the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) and are by far the most powerful ever measured.<\/p>\n

They were likely created by pairs of supermassive black holes spiralling together in hugely energetic collisions throughout the Universe, the researchers say.<\/p>\n

\u201cIt\u2019s like a choir, with all these supermassive black hole pairs chiming in at different frequencies,\u201d said NANOGrav scientist Dr Chiara Mingarelli<\/a>, who worked on the new findings while an associate research scientist at the Flatiron Institute\u2019s Center for Computational Astrophysics<\/a>\u00a0(CCA) in New York City.<\/p>\n

\u201cThis is the first-ever evidence for the gravitational wave background. We\u2019ve opened a new window of observation on the Universe.\u201d<\/p>\n

How were the gravitational waves detected?<\/strong><\/h2>\n

When two supermassive black holes merge together, the colossal forces involved create fluctuations in the fabric of spacetime known as gravitational waves.<\/p>\n

Pulsar timing arrays (PTAs) use the regular radio pulses that are emitted by pulsars, spinning neutron stars, as they rotate to detect these waves.<\/p>\n

As a pulsar rotates, it emits radio waves that reach Earth in precise, regular intervals.<\/p>\n

However, when a gravitational wave passes between a pulsar and the Earth, the distortions in spacetime cause the signal to arrive either earlier or later.<\/p>\n

By analysing these differences, astronomers are able to determine the nature of the gravitational waves causing the change in period.<\/p>\n

The team used observations of 67 carefully chosen pulsars taken by radio telescopes including Green Bank Observatory in West Virginia, the Very Large Array in Socorro, New Mexico, and Arecibo Observatory in Puerto Rico to effectively create a gravitational wave detector the size of our galaxy.<\/p>\n

This makes it possible to study\u00a0gravitational\u00a0waves with wavelengths much longer than those seen by other experiments such as LIGO, which detected gravitational waves for the first time in 2015.<\/p>\n

However, as the wavelengths are so long, the frequencies are very low. This means it takes many years to accurately detect the waves.<\/p>\n

Currently, the team are only able to piece together the overall gravitational wave background, not those created by single events.<\/p>\n

They now plan to collaborate with other researchers across Europe, India, China and Australia to investigate the gravitational wave background in more detail.<\/p>\n

\u201cNow that we have evidence for gravitational waves, the next step is to use our observations to study the sources producing this hum,\u201d said chair of the NANOGrav detection working group Sarah Vigeland<\/a> of the University of Wisconsin-Milwaukee.<\/p>\n

Read more about astronomy:<\/strong><\/p>\n