For human beings, the exploration of outer space has never stopped. Whether it is a Shenzhou spacecraft or an interstellar spacecraft, they are all exploring the vast and boundless universe. In the history of exploration, humans seem to have never heard the sound of the universe, so what about the roaring sound waves from black holes in space? Why does a black hole produce a sound where even light cannot escape from it?
NASA records black hole ‘roar’
Recently, the National Aeronautics and Space Administration (NASA) released an excerpted audio directly on the media platform. In this audio, we can hear bursts of roaring sound waves. It is understood that this sound wave is based on the pressure wave synthesis of the Perseus black hole.
And the audio of this sound wave comes from NASA’s Chandra X-ray Observatory. A vacuum environment cannot transmit sound waves better. In fact, this is a misunderstanding.
Although there is no medium for the propagation of sound waves, there is a large amount of gas in the star clusters around the black hole, which provides a medium for the propagation of sound.
Of course, NASA has discovered more than this kind of sound wave, and also extracted another pressure wave from the black hole in the Perseus galaxy cluster. Since this sound wave propagates in the gas near the black hole, it is difficult for people to hear it clearly if they simply use their ears to distinguish it.
Because even the highest tones of sound produced in supermassive black holes are always below the limit of human hearing. In this audio, the reason why people can clearly hear the roaring sound of the black hole is mainly because NASA has used a new technical method to increase the pitch of the sound notes collected in the black hole through synthesis. It was not until 57-58 that we successfully heard it.
The penetrating power of the sound from the black hole is extremely strong, like a lion roaring in an empty forest, deafening. Some netizens left messages saying: “Black holes can’t even transmit light, how could there be sound released?”
“What I understand is that as long as you reach the speed of sound, can you escape the black hole directly? In the vast and boundless universe, people are just a drop in the ocean.” “This kind of sound wave is like a sports car starting the engine, it is really scary “”Hearing the sound of a black hole, it feels like a call from hell, and the sound is really penetrating.”
Why do you say that even light cannot escape from a black hole? How do people see black holes?
Before clarifying this question, let’s popularize science with everyone. What is a black hole? In fact, a so-called black hole is formed by the collapse of a star of sufficient mass after being burned by the fuel of a nuclear fusion reaction.
A black hole is not a dark cave that we see in our daily life. It can be said that it is a mysterious celestial body, and everything that is sucked in by it will not come out again. Its mass is very large, and the gravitational field it produces is also very strong. This strength is beyond our imagination. For example, it will suck all heavy objects into it.
Take light as an example. We all know that light travels very fast, but in a black hole, even matter like light cannot escape. Why is this?
In fact, a black hole is invisible because it is surrounded by a ring of gas. This space region of the black hole is very strong, and nothing including light can escape. We all know the principle of light refraction in real life. For example, a beam of light shining on a glass will reflect on the ground through refraction.
However, every possible path that light can take in a black hole will eventually bend and return to the inside of the black hole. It would not be able to find a medium for refraction, which means that once light enters the inside of the black hole, it will no longer get out.
So how can humans see black holes?
When we point an astronomical telescope at the galaxy, we find that the surroundings are so dark that we can’t see anything. The main reason for this is that this is the original color of the black hole—black, and the gravitational force of the black hole is very strong. Yes, even the stars not far from it will orbit him, and the light from these stars will shine on the earth.
When scientists observe the Milky Way with telescopes, they find that these stars have been revolving around a blank spot. What is this blank spot? After research, researchers discovered that this blank spot is actually where the black hole is located. I have to say that we are indeed much luckier than our ancestors because we are the first humans to see black holes.
This black hole that reveals its true face is located in the center of a giant elliptical galaxy M87 in Virgo. It is about 55 million light-years away from our earth and has a mass about 6.5 billion times that of the sun. So, how to capture the true face of this black hole?
In fact, the equipment used to photograph it is a “virtual” telescope whose caliber is equal to the size of the earth. About two hundred scientific researchers have combined eight radio telescopes in different places on the earth to form an observation array. The so-called array is a cluster, which is like the array of monster catchers we see in film and television works is ordinary. Several monster catchers set up magic circles from different directions, and then gather their forces to take down the monsters in one fell swoop. The observation array arranged by researchers is actually similar to this principle.
Then using eight radio telescopes, the true appearance of the black hole was finally photographed. When we magnify this photo of a black hole a thousand times, we will find that it is like the briquettes that were burned red, emitting red light. Speaking of this, some people can’t help but ask: “Isn’t the light in the black hole unable to come out? Why do you see red light in it?”
In fact, the reason we see red light is the light emitted by the huge plasma jet produced by the supermassive black hole. As the plasma gets closer to the black hole, it moves faster and faster. At the same time, the space for plasma is getting smaller and smaller.
As a result of this high velocity and crowding, some of the plasma bounces away from the black hole. In the process of plasma jetting, two huge beams of light will be formed. This process is called astrophysical jet. The red light we see in the enlarged picture is actually because the plasma in the jet flows from Not inside the black hole, the light from the jet is outside.
How do black holes produce sound?
From the moment humans explored outer space, the impression left to the world is that “space is silent”, because the space images we obtain through astronomical telescopes are still images, and outer space is also silent in recorded history. Although scientists have demonstrated through countless hypothetical experiments and found that the universe is changing, they have never found that it has sound.
With the continuous advancement of science and technology, researchers have discovered a kind of gravitational wave, which is produced by the collision of black holes and pulsars. This kind of gravitational wave is the sound of oscillation in the universe. Since the universe is sound, how is the sound in the black hole produced?
The black hole sound waves in the audio are synthesized by the sound waves of the M87 galaxy and the Pegasus galaxy. In such galaxy clusters, the galaxy gas provides a sufficient medium, so the sound is recorded. The reason why black holes produce this sound is mainly because after reaching enough medium, sound waves will occur. And this medium is gas. In our cognition, sound is produced by gas particles constantly colliding with surrounding particles.
In a broad sense, sound is actually a longitudinal wave. There is a lot of galactic gas around the black hole, and their density is very low, which is why the sound waves they transmit are of low frequency. This low-frequency sound wave is produced after strong pressure and radiation squeeze each other or rhythmically heat and cool.
From another perspective, the black hole can produce sound waves because it absorbs matter from its surroundings and forms a huge cavity structure, and this low-frequency sound wave is formed by the galaxy gas from the cavity.
Let’s use an analogy, the reason why some people make sounds when walking is that the friction between the shoes and the ground produces a vibrating friction sound. In fact, the sound waves emitted by black holes are the same.
So just how low-pitched is this sound produced in a black hole? When singing, there is often a saying that the octave is lower than the original pitch, and a piano is only seven octaves. The sound wave in the black hole is 57 octaves lower than middle C. If It will take about 16.44 million years to hear this sound wave completely. In order to allow humans to hear the sound of black holes clearly, NASA has used sophisticated new technology to increase the sound of low-frequency black holes to 144 trillion times the original, so that people can hear the sound of black holes.
It can be seen that we are really very lucky to be able to hear the sound of a black hole for the first time living in the world. It can be said that the sound waves from black holes synthesized by NASA can help humans better uncover the mysteries of how large galaxy clusters in the universe are generated. I believe that, in front of the vast and boundless universe, human beings will one day use advanced scientific and technological means to uncover more mysterious veils layer by layer.