Scientists have captured the bassy sound of galaxies colliding

It’s been more than 100 years since Einstein predicted their existence. Astronomers have now been able to pick up the sound of gravitational waves from black holes.

referred to as “Cosmic bass tone“And the”Non-Earth Choir»- But what exactly is the exciting sound that American researchers have now picked up?

Briefly explained, it is the sound of all galaxies colliding throughout history.

According to the researchers, the sound opens a whole new window of knowledge about the mythical creatures black holesblack holesA black hole is a region of space in which gravitational forces are so strong that nothing, not even light, can escape from it. which lies at the center of every galaxy.

– This is huge news, says Dr. Stephen Taylor guardian. He is an astrophysicist at Vanderbilt University in Nashville and led the group behind the discovery.

The big news is that the researchers were able to pick up a small signal from the so-called gravitational wavesgravitational wavesGravitational waves are tiny disturbances in the structure of space.

Galaxies and black holes

These gravitational waves arise from collisions supermassive black holessupermassive black holesThese are black holes that are more than a hundred thousand times more massive than a star. “Ordinary” black holes have a mass about the size of a star.. The signals picked up by the researchers are the common sound of all these collisions through the ages.

In other words, cool stuff. But how big is this really? And what can this discovery be used for?

We let University of Oslo astrophysics professor Austin Elgaroy explain it.

— which isn’t really surprising, because this gravitational-wave background is something we were expected to find, says Elgarøy.

100 years ago, Einstein predicted the existence of such waves. In 2016, scientists found evidence that the universe can expand and contract.

– It’s great, says Elgarøy, that for the first time they have been able to prove the existence of this background of waves.

The room is expanded and compressed

The waves were detected by studying pulsars, which are fragments of large stars that have exploded.

They emit very regular radio waves, much like the flashes of a beacon. Gravitational waves make space stretch or contract a little. This means that the distance to the pulsar changes very little. This causes small disturbances in the rhythm of the “fire signal” being sent.

Researchers collected data over several decades to find this small effect, which can tell us new things about large events:

This is how waves occur when supermassive black holes collide.

It could provide new information about what happens when galaxies form and evolve. All galaxies have a supermassive black hole in the middle. The same applies to the Milky Way.

What will happen to the globe?

– The signal comes from all the galaxy collisions that have occurred throughout the history of the universe. He says his strength could say something about what happens when galaxies collide.

So far, most of what we know about the universe has been discovered by studying different types of light. Elgarøy says that gravitational waves are an entirely different kind of information source. They are less susceptible to the interference that light experiences from astronomical objects on its way to us.

What can the results be used for?

“This is basic research based mostly on curiosity that is being done because we want to understand more of what is going on around us,” says Elgarøy.

– But in the distant future, our galaxy is likely to collide with the Andromeda galaxy. This can help us understand what will happen to our galaxy next, he says.

He says the advanced technology and statistical models used to find out can also be used in other, more practical areas.

The sound of a black hole

Finally, a fun fact:

Last year, it caused quite a stir when NASA tweeted what was supposed to be the sound of a black hole:

This is not the same “gravity trough” that researchers have now found.

Black holes also emit pressure waves. These create ripples in the hot gas that can be translated into a note. Tone accordingly NRK It’s actually 57 octaves below average C, but it’s been tweaked by NASA so we can hear it.

So you have it – the sound of a black hole.