FREE TAPATALK APP

INRM · 25th March 2007, 04:16 PM

I heard it mentioned on a site and I want to know whether it's true or false.

casebro · 25th March 2007, 04:41 PM

context?

My guess is it would be something that conducts sound at supersonic speeds. Like water, which conducts sound faster than air does.

Dr Adequate · 26th March 2007, 08:01 AM

It seems to be a not-very-well-worked-out idea of Jerry Decker and the "free energy" crowd on keelynet.

If someone tries to sell you some acoustic superconductivity, be extremely cautious.

Thing · 26th March 2007, 09:46 AM

A few acousticians have used the term in a metaphorical sense to describe the very low losses that can occur over long distances in underwater acoustic propagation under the right conditions. And someone a while ago proposed what was essentially a microphone with a superconducting element, don't think it ever caught on. But for the keelynet crowd, as Dr A says, it's the usual [(sound = waves) & (electricity = waves)] -> (magical effects no one's observed) -> (gimme a dollar).

[ETA:Casebro, at the risk of being pedantic, superconduction has low resistance, not high velocity. Alright, I'm a pedant.]

Schneibster · 26th March 2007, 09:48 AM

[(sound = waves) & (electricity = waves)] -> (magical effects no one's observed) -> (gimme a dollar)

Heh, yeah, pretty much.

aggle-rithm · 26th March 2007, 09:55 AM

Unless I'm mistaken, this implies the existence of a "coherent sound", in which sound waves act similarly to the way light waves act in a laser. It's a contradiction in terms. "Superconductivity" implies quantum effects, and there's nothing quantum about sound waves.

But I could be wrong. Anyone smarter than me want to comment?

casebro · 26th March 2007, 11:16 AM

Originally Posted by Thing

[ETA:Casebro, at the risk of being pedantic, superconduction has low resistance, not high velocity. Alright, I'm a pedant.]

In electrical superconductivity, yes.

I'll take "Acoustic Superconductivity" for 200, Alex. Wherein, I suppose, less resistance = higher speed. Not the same with electons, since thay all travel at 186,000 furlongs per fortnight.

If you know you are being a pedant, can't you just STFU?

aggle-rithm · 26th March 2007, 01:22 PM

Originally Posted by casebro

In electrical superconductivity, yes.

I'll take "Acoustic Superconductivity" for 200, Alex. Wherein, I suppose, less resistance = higher speed. Not the same with electons, since thay all travel at 186,000 furlongs per fortnight.

If you know you are being a pedant, can't you just STFU?

Well, since sound can't travel faster than sound, by definition, I would think resistance in this case refers to lack of signal loss over a long distance.

Doesn't matter, it's all pseudoscience anyway.

Fnord · 26th March 2007, 01:48 PM

Ignoring the causes of superconductivity for a moment, and the fact that acoustics is not a quantum phenomenon (ignore "phonons" for a moment, as well), one could assume that the term "Acoustic Superconductivity" refers more to an acoustic signal passing through a medium without becoming distorted or attenuated.

The first time I heard this phrase used was in Michigan State University's Physics department. It was tossed around rather carelessly, I might add.

The second time I heard this phrase was while in the U.S. Navy. A sonarman was relating his story about how he listened (via passive sonar) to the crew's voices from the U.S.S. Thresher as she passed crush depth "half a world away." Again, this was not a scientific discussion, but the usage seemed more appropriate.

So, IMHO, "Acoustic Superconductivity" is the passage of an acoustic signal, through a ducting medium, without distortion or attenuation of the original signal. This would be more science than woo.

Disclaimer: I'm not a sonarman or a physicist, just an ordinary electrical engineer. I occassionally work with sound systems.

And somtims my spelin ain't no gud, neether

Thing · 26th March 2007, 02:25 PM

Originally Posted by casebro

If you know you are being a pedant, can't you just STFU?

Because I'm right?

Acoustic resistance (viscous dissipation, thermal losses etc) doesn't slow sound down appreciably, it attenuates its amplitude.

Cuddles · 27th March 2007, 07:39 AM

I was going to go with some kind of technical explanation involving phonons, but I think the response "Wooooo" is more appropriate. Superconductivity means that loss is identically zero. Not "close to zero" or "fairly low", exactly zero. As far as I'm aware this is simply not possible with sound, therefore any talk about acoustic superconducting is either sloppy wording or just plain bollocks.

Alternatively, it refers to the sound you hear when you stick your head in a bucket of liquid helium.

Big Al · 27th March 2007, 07:53 AM

Originally Posted by Cuddles

Alternatively, it refers to the sound you hear when you stick your head in a bucket of liquid helium.

Unless the helium were superfluid - then it would crawl up the sides and out of the bucket.

Otherwise, I imagine your eardrums freezing and shattering in an instant would make the audio experience a little limited.

OK - naughty pedant! [smack]OUCH![/smack]

25th March 2007, 04:16 PM	#1
INRM Philosopher Join Date: Jul 2002 Posts: 5,490	What is Acoustic Superconductivity I heard it mentioned on a site and I want to know whether it's true or false.
INRM Philosopher Join Date: Jul 2002 Posts: 5,490

25th March 2007, 04:41 PM	#2
casebro Philosopher Join Date: Jun 2005 Posts: 6,883	context? My guess is it would be something that conducts sound at supersonic speeds. Like water, which conducts sound faster than air does.
casebro Philosopher Join Date: Jun 2005 Posts: 6,883	__________________ Please pardon me for having ideas, not facts. Some have called me cynical, but I don't believe them. It's not how many breaths you take. It's how many times you have been breathless that counts.

26th March 2007, 09:46 AM	#4
Thing ...now with added haecceity! Join Date: Dec 2005 Location: Beside myself Posts: 512	A few acousticians have used the term in a metaphorical sense to describe the very low losses that can occur over long distances in underwater acoustic propagation under the right conditions. And someone a while ago proposed what was essentially a microphone with a superconducting element, don't think it ever caught on. But for the keelynet crowd, as Dr A says, it's the usual [(sound = waves) & (electricity = waves)] -> (magical effects no one's observed) -> (gimme a dollar). [ETA:Casebro, at the risk of being pedantic, superconduction has low resistance, not high velocity. Alright, I'm a pedant.]
	__________________ One evening I came home to find my wife dissolved in tears. After crystallizing her over a bunsen burner, I managed to elicit the reason. S. J. Perelman Last edited by Thing; 26th March 2007 at 09:50 AM.

26th March 2007, 09:48 AM	#5
Schneibster Illuminator Join Date: Oct 2005 Posts: 3,966	[(sound = waves) & (electricity = waves)] -> (magical effects no one's observed) -> (gimme a dollar) Heh, yeah, pretty much.
Schneibster Illuminator Join Date: Oct 2005 Posts: 3,966

26th March 2007, 09:55 AM	#6
aggle-rithm Ardent Formulist Join Date: Jun 2005 Location: Austin, TX Posts: 14,301	Unless I'm mistaken, this implies the existence of a "coherent sound", in which sound waves act similarly to the way light waves act in a laser. It's a contradiction in terms. "Superconductivity" implies quantum effects, and there's nothing quantum about sound waves. But I could be wrong. Anyone smarter than me want to comment?
	__________________ To understand recursion, you must first understand recursion. Woo's razor: Never attribute to stupidity that which can be adequately explained by aliens.

26th March 2007, 08:01 AM	#3
Dr Adequate Banned Join Date: Aug 2004 Location: Waiting Long Enough By The River Posts: 17,897	It seems to be a not-very-well-worked-out idea of Jerry Decker and the "free energy" crowd on keelynet. If someone tries to sell you some acoustic superconductivity, be extremely cautious.

26th March 2007, 11:16 AM	#7
casebro Philosopher Join Date: Jun 2005 Posts: 6,883	Originally Posted by Thing [ETA:Casebro, at the risk of being pedantic, superconduction has low resistance, not high velocity. Alright, I'm a pedant.] In electrical superconductivity, yes. I'll take "Acoustic Superconductivity" for 200, Alex. Wherein, I suppose, less resistance = higher speed. Not the same with electons, since thay all travel at 186,000 furlongs per fortnight. If you know you are being a pedant, can't you just STFU?
casebro Philosopher Join Date: Jun 2005 Posts: 6,883	__________________ Please pardon me for having ideas, not facts. Some have called me cynical, but I don't believe them. It's not how many breaths you take. It's how many times you have been breathless that counts.

26th March 2007, 01:22 PM	#8
aggle-rithm Ardent Formulist Join Date: Jun 2005 Location: Austin, TX Posts: 14,301	Originally Posted by casebro In electrical superconductivity, yes. I'll take "Acoustic Superconductivity" for 200, Alex. Wherein, I suppose, less resistance = higher speed. Not the same with electons, since thay all travel at 186,000 furlongs per fortnight. If you know you are being a pedant, can't you just STFU? Well, since sound can't travel faster than sound, by definition, I would think resistance in this case refers to lack of signal loss over a long distance. Doesn't matter, it's all pseudoscience anyway.
	__________________ To understand recursion, you must first understand recursion. Woo's razor: Never attribute to stupidity that which can be adequately explained by aliens.

26th March 2007, 01:48 PM	#9
Fnord Metasyntactic Variable Join Date: Oct 2006 Posts: 6,633	Ignoring the causes of superconductivity for a moment, and the fact that acoustics is not a quantum phenomenon (ignore "phonons" for a moment, as well), one could assume that the term "Acoustic Superconductivity" refers more to an acoustic signal passing through a medium without becoming distorted or attenuated. The first time I heard this phrase used was in Michigan State University's Physics department. It was tossed around rather carelessly, I might add. The second time I heard this phrase was while in the U.S. Navy. A sonarman was relating his story about how he listened (via passive sonar) to the crew's voices from the U.S.S. Thresher as she passed crush depth "half a world away." Again, this was not a scientific discussion, but the usage seemed more appropriate. So, IMHO, "Acoustic Superconductivity" is the passage of an acoustic signal, through a ducting medium, without distortion or attenuation of the original signal. This would be more science than woo. Disclaimer: I'm not a sonarman or a physicist, just an ordinary electrical engineer. I occassionally work with sound systems. And somtims my spelin ain't no gud, neether
	__________________ Belief is the subjective acceptance of a (valid or invalid) concept, opinion, or theory; Faith is the unreasoned belief in improvable things; *and Knowledge* is the reasoned belief in provable things. Belief itself proves nothing.**

26th March 2007, 02:25 PM	#10
Thing ...now with added haecceity! Join Date: Dec 2005 Location: Beside myself Posts: 512	Originally Posted by casebro If you know you are being a pedant, can't you just STFU? Because I'm right? Acoustic resistance (viscous dissipation, thermal losses etc) doesn't slow sound down appreciably, it attenuates its amplitude.
	__________________ One evening I came home to find my wife dissolved in tears. After crystallizing her over a bunsen burner, I managed to elicit the reason. S. J. Perelman

27th March 2007, 07:39 AM	#11
Cuddles Decoy Moderator Join Date: Jul 2006 Location: A magical land full of pink fluffy sheeps and bunnies Posts: 16,676	I was going to go with some kind of technical explanation involving phonons, but I think the response "Wooooo" is more appropriate. Superconductivity means that loss is identically zero. Not "close to zero" or "fairly low", exactly zero. As far as I'm aware this is simply not possible with sound, therefore any talk about acoustic superconducting is either sloppy wording or just plain bollocks. Alternatively, it refers to the sound you hear when you stick your head in a bucket of liquid helium.
	__________________ I am not a little teapot.

27th March 2007, 07:53 AM	#12
Big Al Mage Questor Join Date: Sep 2006 Location: La-la Land Posts: 827	Originally Posted by Cuddles Alternatively, it refers to the sound you hear when you stick your head in a bucket of liquid helium. Unless the helium were superfluid - then it would crawl up the sides and out of the bucket. Otherwise, I imagine your eardrums freezing and shattering in an instant would make the audio experience a little limited. OK - naughty pedant! [smack]OUCH![/smack]
	__________________ I don't believe in God. I stopped needing a comfort blanket a long time ago.