The gravitational wave background of the universe has been heard for the 1st time [View all]

By Sharmila Kuthunur published about 2 hours ago

In a historic first, astronomers have detected low-frequency gravitational waves using a galaxy-sized antenna of millisecond pulsars in the Milky Way.



bright points of light spread out throughout space emit a grid-like pattern
Artist's interpretation of an array of pulsars being affected by gravitational ripples produced by a supermassive black hole binary in a distant galaxy. (Image credit: Aurore Simonnet for the NANOGrav Collaboration)

Astronomers have heard the faint hum of gravitational waves echoing throughout the universe for the first time.

For nearly a decade, scientists have been hunting for the gravitational wave background, a faint but persistent echo of gravitational waves thought to have been set off by events that took place soon after the Big Bang and the mergers of supermassive black holes throughout the cosmos. While such a background was long theorized by physicists and sought by astronomers, signals of gravitational waves that make up that background have been hard to detect due to being faint, in addition to vibrating at decade-long timescales. Now, long-term observations have finally confirmed their presence.

In a highly anticipated and globally coordinated announcement on Wednesday (June 28), teams of scientists worldwide have reported the discovery of the "low pitch hum" of these cosmic ripples flowing through the Milky Way.

While astronomers don't definitively know what's causing the hum, the detected signal is "compelling evidence" and consistent with theoretical expectations of gravitational waves emerging from copious pairs of "the most massive black holes in the entire universe" weighing as much as billions of suns, said Stephen Taylor, a gravitational wave astrophysicist at Vanderbilt University in Tennessee who co-led the research.

More:
https://www.space.com/gravitational-wave-background-universe-1st-detection