MH370 - Call for Search & Rescue Help

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#1032104 27-Apr-2014 16:40

I still cannot share in the supreme confidence of the optimistic. People think sound waves go in a straightt line from the black box to the receiver. I do not think it's that easy. I am back up by science of ultra sound waves.

I hope I'm wrong though

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#1032123 27-Apr-2014 17:31

joker97: I still cannot share in the supreme confidence of the optimistic. People think sound waves go in a straightt line from the black box to the receiver. I do not think it's that easy. I am back up by science of ultra sound waves.

I hope I'm wrong though

Sound waves do not travel in straight lines underwater, they are affected by temperature and salinity changes. That is what enables submarines to hide from surface ship sonar. I strongly suspect that is partially why the British Hunter-Killer submarine was sent, to "map" the thermal and saline differences in the water column to enable a better guess as to where the pings are possibly coming from - I can't see that technology in any of the surface ships deployed.

Regards FireEngine

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#1032124 27-Apr-2014 17:33

Bit confused really , I assume nothing else in the sea makes a 37.5Khz signal, yet they detected this signal in two different places 600k's apart. straight line or not that's a big difference to 7km.
so what were they detecting, someone elses black box ? or were they detecting a black box designed to be a distraction :)
I still have a suspicion about the maldives sightings which now look like they are being revisited as a possibility

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#1032137 27-Apr-2014 17:59

A signal is not digital. It is analogue and probably buried within other sounds, maybe even within harmonics of the same band. Hence signal to noise ratio is important to determine how pure that signal is.

Telling where it came from ... well ... there's a saying, like a drop in the ocean

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#1032141 27-Apr-2014 18:09

I believe the range was 1.5km? say its double or triple that, say also there is distortion and increase or decrease of the range due to ocean variables, depth, salinity, temperature. But the vicinity will not be large IF the signals are real. They cannot be as no one has said they ARE the black boxes, and the detections are hundreds of km apart. Again, zero evidence of anything

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#1032144 27-Apr-2014 18:14

That's what I don't understand. So at 1.5km you get a signal, at 1.6 km you have no signal? At 1.576km?

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#1032234 27-Apr-2014 21:35

CNN had an 'expert' discussing it with a video diagram showing how waves could bounce km's along layers of the sea. It is possibly one explaination as to why the chinese also picked up some signals many km's away, and they were so patchy. I think technology will need to improve before they will find it. They did eventually find the titanic, although they did have a rough location for it, but that wasn't as deep.

From what I've read elsewhere there is pretty well no chance of the signals going as far as the Chinese were from the other area where the pingers were heard.

I think the Chinese were just putting on a show for the media to be shown to the people at home. It sure looked like a set up having the media there to "witness" the event. I read on another site that an expert in searching for the pingers fell off the chair laughing when he saw shots of the Chinese claiming to have heard the pingers.

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#1032264 27-Apr-2014 22:34

Technofreak:

I think the Chinese were just putting on a show for the media to be shown to the people at home. It sure looked like a set up having the media there to "witness" the event. I read on another site that an expert in searching for the pingers fell off the chair laughing when he saw shots of the Chinese claiming to have heard the pingers.

I wouldn't be surprised. What I was describing previously I believe is referred to as the Sofar channel, 600-1500m under the sea, which can carry sound many kms. http://oceanexplorer.noaa.gov/explorations/sound01/background/acoustics/media/sofar.html

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#1032267 27-Apr-2014 22:39

it refers to "low frequency" sound waves which i believe is like in the tens to hundreds of Hz.

no idea how 37kHz would behave.

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#1032296 28-Apr-2014 00:03

rule number 1 is never believe anything the Malaysian officials say.

so the demented ex dictator of the country has finally spoken (he is still wildly outspoken yet immune to criticism due to his stranglehold on the present rulers despite his retirement - think sir alex ferguson of man utd) http://www.smh.com.au/world/former-malaysian-pm-lays-blame-on-boeing-for-mh370-disappearance-20140427-zr0cz.html

PS - he believes that 9-11 was ochestrated by the CIA

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#1032795 28-Apr-2014 19:56

joker97: it refers to "low frequency" sound waves which i believe is like in the tens to hundreds of Hz.

no idea how 37kHz would behave.

I was also curious about ultrasonic and in http://webpages.charter.net/jameslh/science/whaletalk.html found this:

So while low frequencies can travel >1000 km in the SOFAR channel, it seems unlikely ultrasonic will get very far (scale is dB/km).

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#1032802 28-Apr-2014 20:06

dwl:
joker97: it refers to "low frequency" sound waves which i believe is like in the tens to hundreds of Hz.

no idea how 37kHz would behave.

I was also curious about ultrasonic and in http://webpages.charter.net/jameslh/science/whaletalk.html found this:

So while low frequencies can travel >1000 km in the SOFAR channel, it seems unlikely ultrasonic will get very far (scale is dB/km).

Thanks dwl. I was looking for information that clarified the attenuation characteristics of the various frequencies.. Also some of the articles quoted in previous posts didn't quantify the exact frequencies that were being discussed except to say low frequencies. Your info ties in with what I understood was the case with the pinger frequency of 37.5 kHz

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#1041980 12-May-2014 09:32

Physicist and satellite engineers raise serious questions about Inmarsat's predicted flight path. Additional source of doppler shift may be unaccounted for:

http://m.theatlantic.com/technology/archive/2014/05/why-the-official-explanation-of-mh370s-demise-doesnt-hold-up/361826/

Still not enough information released to know if the incomplete data was used to calculate the projected flight path. I'd like to see all the available data released.

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#1041995 12-May-2014 09:56

I wonder if those who were supremely Confident are still as confident.

I never shared any confidence. As I said if they find it great, chances are, no one knows where it could be

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#1042024 12-May-2014 10:32

joker97: I wonder if those who were supremely Confident are still as confident.

I never shared any confidence. As I said if they find it great, chances are, no one knows where it could be

An interesting article in gzt's post.

What hasn't been explained though, is the pings the Aussies tracked over several days, if they didn't come from MH370 where did they come from?.

There were two of them (as was expected, one each from the CVR and FDR) and they were at the right frequency (frequency that doesn't occur naturally). If they didn't come from MH370 where did they come from? No one has come up with a credible explanation to explain that these pings could have come from a source other than MH370.

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