Listen to a black hole.

[Workingman]

Here.

It is not really the sound of the black hole, that's impossible, more the sound of the interstellar gas as it swirls around and falls over the event horizon. The gas is just dense enough for sound waves to propagate within it but only at frequencies below which the human ear can detect. These frequencies have been speeded up - shifted by 57 and 58 octaves - so we can hear them.

Talk about weird.

[Kaz]

It certainly is!

[Suff]

I always feel that these "massaged" soundtracks are there to get people interested and perhaps bring in new talent.

Because there is no sound in space and these waves are not audible and would not be audible on earth either, even speeded up.

It makes a nice story but in reality it is a gimmick. Plenty enough stuff going on in space right now without manufacturing soundtracks which don't actually exist. I know it represents a whole lot of dry and unpalatable scient to get to this point. I just don't find it as interesting as other things we are currently doing.

Although the moves to understand the basic building blocks of our universe are important and fascinating, nothing so slow as "sound" could escape a black hole.

It is fortunate that black holes don't grow at close to the speed of light. Because given the red shift action of the gravity well of a black hole, you would not see it for very long before you fell into it. Now calculating that is very useful. Even if we couldn't do anything about it.

[Workingman]

Ha, you fell into the falsehood of "In space no one can hear you scream". © Alien - Ridley Scott.

Reality is not a film.

Sound needs a medium to travel through be it air, water, dust, rock, metal etc. There is plenty of "stuff" in areas of space for sound to propagate. Look at the Pillars of creation photograph. Space might be mostly a vacuum, but without physical matter there would be no stars or planets. Without it - the stuff - we would not be here.

We cannot see in the IR or UV spectrums but our telescopes can and their images are 'converted' to the visible - see Hubble and JWST. Nor can we hear in the radio wavelengths yet those are adjusted so we can 'hear' them. Look up CMBR. I take it you own a radio or TV.

Are they gimmicks? Without them the Universe would be blind to us.

nothing so slow as "sound" could escape a black hole.

I take it you did not read my OP.

[Suff]

I did and I followed it up.

The "sound" being presented here are an audible representation of flux waves set up by the gravitational pulses sent out by material as it is absorbed by a black hole, probably as it is circling the accretion disk before being torn apart. So far as I'm aware, even if they could hear it without speeding up, these flux waves implied by the gravitational waves are outside the hearing of anything living.

Maybe I just woke up grumpy?

[Workingman]

There are limits as to how "fast" a black hole can grow and they vary with their different masses, their age, and the amount of other matter surrounding them and how "near" it is. The maths is astoundingly difficult so I won't even try. Two simple equations are Einstein's E=mc² and Newton's F=G x m¹m²/r² where G= 6.67430(15)×10-¹¹ N m2·kg-² and they are only small units within much more complex equations

The Milky Way is about 12.9 billion years old and is thought to have upwards of 200 - 400 billion visible stars at about 100,000 light years in diameter. Its mass is about 1.9 trillion solar masses. Its supermassive black hole, Sagittarius A*, is 4,100 million solar masses (about 4 million times the mass of the Solar system) - a spot on a pimple on a gnat's bum. In Universal terms growing the black hole is an achingly slow process.

I think we are safe for a while.

[Suff]

I think we are safe for a while.

So do I. But it is an intriguing thought. If you were close to a black hole would you feel it before you saw it?

[Workingman]

Now then, you cannot see it as it gives off no light, you cannot hear it because its sound is well below our hearing range, even for whales that use infrasound, so that leaves gravity.

My guess is that gravity has it, and if it does you and you mass are so near as to not be enable to get away. A Raptor engine is not strong enough.

[Suff]

A Raptor engine is not strong enough.

Quite right. No engine in strong enough, it would take FTL technology and that doesn't (won't?) exist.