Can you hear a black hole or "The echoes of the Big Bang still go through the universe"

We all know that sound in space does not apply. No matter how loud the engine of a spacecraft flying next to the observer, he will not hear it. Nevertheless, some sounds still spread throughout the Universe, although man cannot hear them without the help of equipment. We are talking about infrasounds with a very long wavelength and a very low frequency, which can spread in the clouds of interstellar dust and gas.

One example of such a source of infrasound is a super massive black hole located in the center of a giant cluster of galaxies, which is called the Perseus cluster. This object is located 250 million light years from Earth. The sound emitted by a black hole is 57 octaves lower than (the notes of Do) of the first octave, it is a million billion times lower than the frequency of sound that can be heard by humans. The lowest sound a person can hear has a frequency of 20 Hz. The sound wave generated by a black hole has a lower frequency: 1 oscillation of 10 Myr. This is literally the sound of Eternity.


The sound wave generated by a black hole in the Perseus cluster was detected by the Chandra orbital X-ray observatory.
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The orbital Chandra observatory was able to capture concentric formations in a gas and dust cloud surrounding the Perseus cluster. These formations are similar to the circles on the pond, which go on the water, if you throw a stone into the pond (well, or a duck goes down to the pond). The brighter formations are the peak of the wave, where the gas concentration is maximum. Darker areas - the area of ​​minimum gas pressure, the base of the wave. These sound waves propagate hundreds of thousands of light years from the source, and the sound disappears where there is no gas or dust at all. Between the Earth and the cluster there are huge empty areas of space where there is a very low concentration of gas, therefore the sound from a black hole does not reach us.

The first sound in the universe

If someone could go to the starting point of the Universe, or rather, to a point that is 760000 years from the Big Bang, then this person or apparatus could hear the sound of the Universe.



At this time, the density of matter was high enough to transmit sound waves. And they spread, the universe sounded. Now there is no sound, but there is a relic radiation, which is a kind of carrier of the first sound. 760000 years ago (we will leave a reference to this time) the sound, spreading through the gaseous matter of the Universe, caused changes in the density of matter, wave. Accordingly, these fluctuations caused changes in the temperature regime of their surroundings, and temperature fluctuations, in turn, left their mark on the background radiation.

Specialist from the University of Washington, physicist John. J. Gremer (John G. Cramer) tried to reconstruct the ancient sound. This sound can be heard here or in the video above.