Space

Discovery of the background gravitational waves of the universe

According to Einstein’s theory of relativity, when black holes collide, strong gravitational waves are produced. The existence of these gravitational waves has been captured by the LIGO gravitational wave detector and shown.

Scientists have now discovered the gravitational waves underlying the universe. The waves of this background gravitational wave are too far apart to be captured by the ordinary LIGO system. So this wave was captured using another technique.

Gravitational waves are massive. In other words, there are vibrations in space-time (space and time) that occur when objects with large gravitational forces pass through space or collide with each other. As these waves pass through, the patio itself vibrates and distorts.

It is said that the cosmic background gravitational wave captured now is the most powerful gravitational wave ever captured. Scientists believe that these gravitational waves are generated when supermassive black holes in the centers of galaxies merge.

These gravitational waves are not only powerful, but their lifespan is decades long. Scientists estimate that this giant gravitational wave carries millions of times more energy than normal gravitational waves from the merger of a neutron star and a black hole.

“I have to say that it is similar to a large orchestra because of what it looks like. Gravitational waves came out of the great black hole. Gravitational waves emanate from the nearby supermassive black hole,” explained Chiara Mingarelli, one of the researchers involved in this research. He is one of more than 190 astronomers and physicists involved in this research.

The discovery was made using several radio telescopes around the world. From these radio telescopes, 68 pulsars were studied and identified in detail. This result was announced after a detailed analysis of the data obtained by studying these pulsars for two decades.

Pulsars are neutron stars that rotate at very high speeds centered on an axis. These neutron stars emit radio waves at the right time.

The radio waves emitted by pulsars are very weak by the time they reach Earth. So they spend many hours studying using very large radio telescopes.

Gravitational waves captured by previous LIGO experiments are high-frequency gravitational waves. Also, the lifetime of LIGO gravitational waves is very short.

Now, gravitational waves have a fixed frequency, and it takes many years for each wave to pass through. So it is impossible to capture this kind of gravitational wave with LIGO.

So, to capture these waves, astronomers have to use another method. Here comes the role of pulsars:

Pulsars spin so fast that the radio waves emitted by them oscillate as they spin. Why? It’s like a light bulb is shining through. The faster the rotation speed, the faster the cutting speed.

If you want to see this with your own eyes, tie a flashlight to a string and turn it around.

The radio waves emitted by pulsars are directed in the same direction as a flashlight, so the pulsar will spin around as it rotates. If you look at this from a distance, you will see that the radio waves are crossing each other.

Among them is a very fast millisecond pulsar. These pulsars are spinning hundreds of times per second. So the radio waves from them will hit hundreds of times per second.

Supermassive black holes are large black holes at the centers of galaxies. When two galaxies merge with each other, these black holes merge with each other. It can be assumed that mothers who do not cooperate with each other for a long time Due to this mutual rotation, the space-time surrounding the pair of black holes causes waves to form as they contract and stretch.

The lifetime of these resulting gravitational waves is very long, so the large gravitational waves coming from different parts of the universe will converge with each other.

It’s like in a room where there are many people, you can’t hear each person’s voice, and it just comes out as background noise.

It can even be said to be the background sound of the universe. Scientists have re-identified this background wave from data from pulsars.

According to astronomers, this finding is 99% sure to be real. (99% confidence level), But more research is needed to confirm this. In the sense of scientific research, a theory or a finding cannot be confirmed by a single research result. Further research is needed to confirm it.

The next step is to search for gravitational waves by capturing the radio waves emitted by 13 radio telescopes around the world and more than 100 pulsars. Experts believe that the result obtained in this way will be very strong.