Posted on 08/14/2009 9:31:19 AM PDT by HIDEK6
Caption:"The Chandra data show sound waves rippling through hot gas that fills the Perseus cluster. The features were discovered by using a special image-processing technique to bring out subtle changes in brightness."
"Is this image you are talking about a simple time lapse image acquired over the 53 hours; or is it more like a race track photo finish image?"
53hr shutter speed on an object ~250Mly away...
Even though the shutter speed is 53hrs, there is no motion to be observed. The time lapse is needed to gather spacial info. 2.5Byrs of event is contained in that still.
I would note that the ripples are not concentric and diminish abruptly rather than with distance. I don't see yet how one can associate this image with a wave generator. I also don't see how you come up with a velocity for the "signal" being suggested.
ML/NJ
Yes.
" I just am not familiar with the use of the word ripple as a scientific term."
It's English and portrays waves through a fluid cross section very well. The fluid in this case is a gas embedded in a field of galaxies.
"I would note that the ripples are not concentric and diminish abruptly rather than with distance."
The entire assembly appears to have a 2.5Bly radius. The lack of concentricity is caused by spacial inhomogeneitiesous in the gas and resultant speed of sound variation, and rotational effects. There's no apparent dissipation, because the density peaks in the longitudinal waves are substantial and gravity will maintain that configuration. Pressure waves through gas regions generate stars.
The generating wave is a resultant og the BH's gas jet. If the ejecta moved at c, there would be 120 ripples. Since there are only ~5.5 ripples/radius, the ejecta, or speed of sound in the gas, is 0.05c.
Well, now that I think about it we did use "ripple tanks" in my high school physics class (PSSC - it was pretty good) to study waves.
The entire assembly appears to have a 2.5Bly radius.
And how do you know this?
ripples/radius
What kind of a unit is this? Radius of what?
Since there are only ~5.5 ripples/radius, the ejecta, or speed of sound in the gas, is 0.05c.
I don't understand. Does the number 5.5 come from the number of wavelengths extending from the generating object? I still don't understand why these peaks(?) don't extend out indefinitely from the center. How do you infer a wave velocity from any of this?
ML/NJ
"And how do you know this?"
The NASA guys said so.
"Radius of what?"
That Persius cluster. The gas cloud is embedded in the galaxies. That's the same as saying the galaxies are embedded in the gas cloud. Both are the Persius cluster which has the radius of 2.5Bly.
"I still don't understand why these peaks(?) don't extend out indefinitely from the center."
There's nothing but intergalatic space outside the Persius cluster. That means there's nothing to propagate a longitudinal shock/sound wave through.
"Does the number 5.5 come from the number of wavelengths extending from the generating object?
Yes.
"How do you infer a wave velocity from any of this?"
If the jet v was c, there would be 120 ripples. There is only ~5.5, so... 5.5/120=0.05c.
don’t think sound waves, think math
... Also, the BH jets would have had a startup time in the cluster.
Any one that can understand what you wrote is either a genius or schzoid...I am not a genius..
Closer to home...
Somewhere I found a geologic _audio_ recording of the Indonesian Christmas Eve Tsunami. Fascinating sound - with sub-bass so strong it blew out my iPod headphones.
ML/NJ
Here's a paper that covers the matter: A deep Chandra observation of the Perseus cluster: shocks and ripples" Fig 5 gives a radius of 163kly. The shock/sound velocity is ~0.005-0.02c.
This discussion the two of you are having is above my pay grade. WAY above my pay grade. But the fact that you’re having this discussion at all has me more encouraged about the future of FR than anything I’ve read here for quite a while. Hope you don’t mind me peeking in the window from time to time just because I enjoy seeing IQ points flying around a room.
ML/NJ
I just heard about this from my daughter, googled it up and found it here, and thought you might be interested in it.
Job 38:6-8
6 On what were its footings set,
or who laid its cornerstone-
7 while the morning stars sang together
and all the angels shouted for joy?
8 “Who shut up the sea behind doors
when it burst forth from the womb,
Okay, I just did a little research on your links, and the legendary, “Brown Noise.”
I didn’t know that they actually tested this theory on Mythbusters.
LOL!!
Without checking it out for myself, I’ll tell you how to do it -
an octave is a doubling of frequency.
So take the frequency of the “middle B flat” and double it 40 times (times 2 to the 40th power) and compare that to the frequency of yellow.
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