Gravitational waves were already discovered in 2016, but this Thursday afternoon an unpublished study was presented that could explain the beginnings of the Universe: a group of international scientists managed to detect low-frequency gravitational waves that cause a “serious sound” that propagates throughout the cosmos.
“This note will come from supermassive black holes that are inside galaxies. It is possibly the result of colliding galaxies, where in the center, these holes are going towards each other, they are still dancing and they produce a gravitational wave that is so low in frequency that it can take one or two light-years to pass,” he explains. to TSF astrophysicist Jose Fonseca.
To discover this “background noise” of low-frequency gravitational waves, this group of scientists observed pulsars, that is, “what remains of supermassive stars, in which the star explodes and what remains of the core is a star.” of neutrons”. .
The astrophysicist affirms that some of these neutron stars have the axis of rotation and the magnetic axis “misaligned”, thus creating “a beam of light”. Pulsars “are almost like clocks in the sky. They are so precise that they help us measure time very precisely.”
But what are gravitational waves? Recalling Albert Einstein’s Theory of Relativity, José Fonseca refers to gravitational waves as “oscillations in space-time” and compares them to a boat on the water. “The ship goes up and down. By disturbing spacetime, we disturb the way we measure time and distances. The jitter is actually in the spacetime mesh and what we observe are the effects of the jitter on the mesh of space-time.”
There is still no explanation for the sound of these low-frequency gravitational waves, which has now been detected, but the astrophysicist advances a theory by TSF: “The most likely explanation is supermassive black holes living in the centers of galaxies, which are orbiting each other and are still in that dance where they are going to collide.”
Another possibility is that “primordial gravitational waves are latent noise from the beginning of the Universe.”
This is an essential result that could explain the early history of the Universe, such as the Big Bang, as well as the evolution of galaxies. “The general idea we have of the formation of structures in the universe is that first small galaxies were created and then, over time, they collided and joined to create larger and larger galaxies. What we believe is that most galaxies will have massive mass. black holes at the center of galaxies and these galaxies colliding also caused the black holes themselves to collide to form even larger black holes, but because they are such massive entities they take a long time to collide. the universe and, therefore, they will not even have collided, they keep dancing, waiting to collide”, clarifies the astrophysicist.
Now, with this discovery, scientists already have a way to detect low-frequency gravitational waves, opening “a whole new window for us to study and observe the beginning of the universe.”
TO TSF, José Fonseca confesses that the sound that was heard from these low-frequency gravitational waves was “much stronger than expected” and compares it to a symphony orchestra, where there are “some sounds more serious and others more acute”. “If space-time and the space-time grid were always fluctuating, what we hear now is the bass part of this symphony orchestra,” he says.
And this is a different sound than black holes make when they collide. In this case, it is “the upper part” of the symphony orchestra.
“If it is the black holes that create this sound, what we hear now is the dance before they come together. It is a different state in the process of black holes going towards each other”, she clarifies.
This was a discovery made by the NANOGrav consortium of scientists, but José Fonseca stresses that there are several other entities that study and monitor pulsars in the Universe, namely the European Pulsar Timing Array.
According to the astrophysicist, in the future, monitoring of pulsars will be carried out by a “giant telescope”, the Square Kilometer Array Observatory, of which Portugal is a part.
Source: TSF
