the real infrasound/ la montes fundamental?

Black Hole Sound Waves

Sound waves 57 octaves lower than middle-C are rumbling away

from a supermassive black hole in

the Perseus cluster.

Listen to this
story via streaming audio, a downloadable file, or get help.

Sept. 9, 2003:
Astronomers using NASA's Chandra
X-ray Observatory have
found, for the first time,
sound waves from a
supermassive black hole. The
"note" is the deepest
ever detected from any object in
our Universe. The
tremendous amounts of energy
carried by these sound
waves may solve a longstanding
problem in astrophysics.

The black hole resides
in the Perseus cluster of
galaxies located 250
million light years from Earth. In
2002, astronomers
obtained a deep Chandra
observation that shows
ripples in the gas filling the
cluster. These ripples
are evidence for sound waves
that have traveled
hundreds of thousands of light years
away from the cluster's
central black hole.

Right: The Perseus
cluster of galaxies. Each fuzzy object is a galaxy. Unseen is a vast
cloud of hot gas filling the cluster.
Near the center of it
all lies a supermassive black hole.

Earlier observations had
revealed the prodigious amounts of light and heat
created by black holes.
"Now we have detected their sound, too," says Andrew
Fabian of the Institute
of Astronomy in Cambridge, England, and the leader of
the study.

In musical terms, the
pitch of the sound generated by the black hole translates
into the note of B flat.
But, a human would have no chance of hearing this
cosmic performance
because the note is 57 octaves lower than middle-C. For
comparison, a typical
piano contains only about seven octaves. At a frequency
over a million billion
times deeper than the limits of human hearing, this is the
deepest note ever
detected from an object in the Universe.

"The Perseus sound waves
are much more than just an interesting form of black hole acoustics,"
says
Steve Allen, also of the
Institute of Astronomy and a co-investigator in the research. "These
sound
waves may be the key in
figuring out how galaxy clusters, the largest structures in the
Universe, grow."

Above: Peering into the
heart of the Perseus Cluster (left), the Chandra X-ray Observatory
detected sound waves
rippling through the gas
(right). [more]

For years astronomers
have tried to understand why there is so much hot gas in galaxy clusters
and so
little cool gas. Hot gas
glowing with X-rays ought to cool because X-rays carry away some of the
gas'
energy. Dense gas near
the cluster's center where X-ray emission is brightest should cool the
fastest. As
the gas cools, say
researchers, the pressure should drop, causing gas from further out to
sink toward the
center. Trillions of
stars ought to be forming in these gaseous flows.

Yet scant evidence has
been found for flows of cool gas or for star formation. This forced
astronomers
to invent several
different ways to explain how gas contained in clusters remained hot.
None of them
were satisfactory.

Black hole sound waves,
however, might do the trick.

Previous Chandra
observations of the Perseus cluster
reveal two vast,
bubble-shaped cavities extending away
from the central black
hole. These cavities have been
formed by jets of
material pushing back the cluster
gas. The jets, which are
a counter-intuitive side effect
of the black hole
gobbling matter in its vicinity, have
long been suspected of
heating the surrounding gas.
But the exact mechanism
was unknown. The sound
waves, seen spreading
out from the cavities in the
recent Chandra
observation, could provide this heating
mechanism.

Right: an illustration
of cavities and sound waves in the hot gas
filling the Perseus
cluster. [more]

A tremendous amount of
energy is needed to generate
the cavities, as much as
the combined energy from 100
million supernovas. Much
of this energy is carried by the sound waves and should dissipate in the

cluster gas, keeping the
gas warm and possibly preventing a cooling flow. If so, the B-flat pitch
of the
sound wave, 57 octaves
below middle-C, would have remained roughly constant for about 2.5
billion
years.

Perseus is the brightest
cluster of galaxies in X-rays, and therefore was a perfect Chandra
target for
-- -Kraig Grady
North American Embassy of Anaphoria Island
http://www.anaphoria.com
The Wandering Medicine Show
KXLU 88.9 FM WED 8-9PM PST

--- In metatuning@yahoogroups.com, kraig grady <kraiggrady@a...>
wrote:

>
> <snip>
> In musical terms, the pitch of the sound generated by the
> black hole translates into the note of B flat. But, a human
> would have no chance of hearing this cosmic performance
> because the note is 57 octaves lower than middle-C.

very interesting article, Kraig!!

assuming A=440 Hz as a reference and 12edo as the tuning
to determine this "Bb", the frequency coming from Perseus is:

(220 * [2^(1/12)] ) / (2^57) = 1.61733 * 10^-15 Hz

how would the wavelength of that be calculated?

i know how to do it for a case where the sound occurs here
on earth, in the medium of air ... but not for something
like this.

-monz