‘Background noise’ in the universe – researchers announce groundbreaking discovery

Many research teams are finding evidence of a kind of “background noise” in the universe. Gravitational waves can reveal many mysteries.

Bonn – If you look up at the night sky, it seems all is quiet there. Occasionally, the satellite would speed up, otherwise nothing would move. But appearances are deceiving. The universe is constantly fluctuating, but the gravitational waves that rock the universe are invisible to the human eye and most scientific instruments.

For many years, researchers have been trying to detect gravitational waves with what are called pulsar timing arrays. Pulsars are celestial bodies that emit pulsations at very regular intervals. They are so regular that researchers have long hypothesized that these regular pulses should tell you when you are being affected by gravitational waves.

“Pulsars are excellent natural clocks. We use the amazing regularity of their signals to search for subtle changes in their beats and thus detect the exact expansion and compression of space-time through gravitational waves from the distant universe,” explains David Champion from the Max Planck Institute for Radio Astronomy in Bonn Announcement from the European Pulsar Time Group (EPTA).

Gravitational waves detected: ‘background noise’ in the universe

Researchers around the world have now succeeded in detecting a kind of “background noise” from gravitational waves in the universe. Stephen Taylor (Vanderbilt University) explains in one communication From the Nanohertz North American Gravitational-Wave Observatory (NANOGrav).

“Pulsars are actually very faint radio sources, so it takes us thousands of hours a year at the largest telescopes in the world to do this experiment,” says researcher Maura McLaughlin. There are many giant gravitational-wave detectors around the world with different pulse timing arrays—EPTA and NANOGrav are just two of them—that have now made it possible to detect gravitational waves at much lower frequencies than was previously possible. “We are opening a new window into the world of gravitational waves in the nanohertz range, where we can observe unique sources and phenomena,” says scientist Katerina Tiburzi.

Gravitational waves from the dance of two black holes

In a coordinated action, studies by several research groups at the same time – NANOGrav Studies – were published in the specialized journal Astrophysical Journal LettersEuropean Studies in a specialized journal Astronomy and astrophysics.

This isn’t the first time research teams have detected gravitational waves. It was successful for the first time on September 14, 2015 with the LIGO detector in the USA. In 2017, researchers Rainer Weiss, Barry Barish, and Kip Thorne received the Nobel Prize in Physics for the first direct evidence of gravitational waves occurring in space. The measured gravitational wave signal came from two black holes orbiting each other, getting closer and closer and finally merging.

“contain information about some of the best kept secrets in the universe”

The now detected gravitational waves are a kind of “background noise” in the universe, a “hum” on which researchers have high hopes. “Very low gravitational waves contain information about some of the best-kept secrets of the universe,” says Stanislav Babak, a co-author of the study. “The results presented today mark the beginning of a new journey into the universe to unravel some of its unsolved mysteries,” says his colleague Michael Keith.

But what exactly is the “buzz” in our world? NANOGrav researchers believe that pairs of supermassive black holes orbiting each other emit low-frequency gravitational waves. Over time, gravitational waves from different pairs overlap – background noise or “buzz” is generated and is seen as a unique pattern in the pulsar data. (unpaid bill)