[KayEyeDoubleDee]

Okay, after reading the original article, I sent the following to the author:

... I'm ... curious about the original article. Consider the introduction:

"B-flat flying through space ... 57 octaves below the keys in the middle of a piano."

Wow, 57 octaves below B-flat, eh?

Assuming we are using A-440 Hz (and not some pre-Bach value), the B-flat below middle-C vibrates a medium only 233.0818808 times per second.

57 octaves below that is roughly 1.61733e-15 vibrations per second. This means that the period of the wave is the inverse of that number, or 6.18303e+14 seconds. But, ...

6.18303e+14 seconds
equals
1.71751e+11 hours
equals
7156282833 days
equals
19606259.51 years.

Call me suspicious, but how exactly does one make a measurement of a physical process which occurs once every 19 million years? Is there something in the fossil record, perhaps scratchings on a rock thanks to an inquisitive T. Rex?

Granted, if the note in question is 57 octaves below the B-flat which is above middle C, then you only have to wait half that long.

[KayEyeDoubleDee]

Any ideas on my question in #19 above, concerning actually measuring that B-flat?

[Aracelis]

perhaps scratchings on a rock thanks to an inquisitive T. Rex?

ROFL!

As to your inquiry, let's ask the FR resident brainiacs (my background is in carbonate geochemistry). Gentlemen, would you have any comments on Post 19? Thanks!

[Physicist]

Call me suspicious, but how exactly does one make a measurement of a physical process which occurs once every 19 million years? Is there something in the fossil record,

Yes, in a way. The fossils aren't to be found in Earth's rocks, of course, but in the nebula surrounding the black hole. Per the article:

Every 10 million years, a fresh wave bubbles out of the system.

...

As the pressure peaks travel outward from the cavities around the black hole, collisions occur between atoms in the gas, generating X-rays that reveal a concentric ring pattern. Being a form of light, X-rays can traverse the universe sans any medium, and these are what Chandra detected.

The sound waves rapidly die out, their energy converted to heat. So in essence the B-flat was seen, not heard, from 250 million light-years away.

So there you have it: a series of concentric density waves, spaced at 10-million-year intervals, centered on the black hole.

[RadioAstronomer]

The frequency is about 9.5 million years between wave crests. (It was the B-flat above the middle C. :-)

What they are "seeing" are ripples in the hot gas inside the cluster that the black hole resides in. By measuring these ripples and the effects from them, the sound waves can be calculated.

[MetalHeadConservative35]

now THAT is some low end..if only i could get that kinda low end outta my amp ehehehehe