an Idea just occured to me after finding an old amplfier in my junk box, I hooked it all up and it worked lovely, I attatched a large coil (several thousand turns of copper wire) to the input and could hear all sorts of sounds from my mobile phone to my mouse when it moved, even the digits changing on my watch when placed inside this loop.

 

I`m now wondering if it would be possible to listen to a displacement reaction of a ferro-magnetic substance in a test tube, IE/ I drop a peice of magnessium into a soln of Iron Sulphate, Iron metal will appear out of the soln.

 

since Iron is a magnetic metal, could this be heard as it appears in a magnetic field, much like the pickup head on a Guitar detects the tiny movement of the string?

 

the idea may be a little crazy and I can`t think of any application for it other than pure curiosity, so I`ve put it in here

i smell an experiment brewing... can't see any reason why it wouldn't work so give it a shot.

Yes and tell us what happened!!? Did it work? How did it sound like?

well there`s a little bit of a hold-up at the moment, I`m trying to get some good iron Chloride (I`ve changed my mind about the sulphate) with which to do this experiment see: http://www.scienceforums.net/forums/showthread.php?t=15956

 

the reason I want the Chloride as opposed to a sulphate for instance is that the reaction is much more vigorous, and would likely present better results.

stay tuned though, I`de don`t give up that easily

I have a Partial success!

using the Barkhausen effect I can hear a tiny tiny clicking noise when a peice of iron is formed and moves off the Magnesium towards the magnet and then hits the side of the flask, but as predicted, the Iron Sulphate and magnesium reaction isn`t vigorous enough to hear any formation activity, however I will be using these newly formed iron particles as my source for the iron chloride that I`de like to try next

for those interested in the Barkhausen effect, this: http://jlnlabs.imars.com/spgen/barkhausen.htm and a good google search will give you a good idea of the electronic side of the set-up

BINGO!!!!

 

with the magnet directly OUTSIDE the coil and the test tube inside with the Ferric Chloride and Magnesium powder added, there`s a Rush of "white noise" as it reacts!

it freakin` WORKS!!!!

 

YT does his happy dance around the Lab )

Cool. Now you don't need to be taking LSD to hear a visual event!

LOL, actualy I`de hoped for something a little more interesting than just plain old White Noise, Hysterisis squeeks would have been cool, but nada, it wasn`t to be on this setup.

btw, I`ve just tried this same experiment on my electric guitar as close to the pickups as possible, there`s no effect or result, or at least nothing you can actualy hear.

 

the pickup coil I used is a 2.5 inch x 1 and 1/16`th inch truncated conical base 2 3/4", Osciliscope alignment coil (circa 1956) several 1000 turns copper.

 

the amp was from a late 70`s dual deck Hammond organ, I can`t give any more info as I striped it down about 5 year ago and have no more data on it, but it`s really nothing special at all, a more modern one as shown in the link I provided a few posts ago will do the same thing

it`s the pick-up coil and the magnet that seems to be "Critical"

This is funny. I also once did a similar experiment, but then with electrolysis.

 

Take a 12 V voltage source (e.g. old PC power supply). Take a 10 Ohm power-resistor and place this in series with the voltage source. Assure that the resistor is not becoming too hot, otherwise use two parallel resistors of 22 Ohm.

 

Perform electrolysis of a concentrated NaCl solution. In parallel to the NaCl solution, also take a 10 kOhm resistor in series with a 10 uF capacitor. The voltage over the 10 kOhm resistor will be 0 on average, but there is a considerable AC-component. If you connect this to the LINE input of an audio amplifier, then you'll hear the electrolysis proceeding. Quite impressive. It is a kind of roaring noise. Be careful here and use low volume and then turn up the volume. The signal level can be quite high and you may damage your loudspeakers if performed carelessly.

Hmmm... interesting idea!

using the same design setup with the amp and the capacitor, but without external power for the electrolysis, it should be possible to listen to a "battery" as one of the electrodes fizzes away also, the output current wouldn`t be a constant and that when amplified should be quite audible too, and not dependant on any magnetism either

one carbon and one magnesium electode in some diluted HCl should be plenty reactive enough I would have thought

 

it`s a real pity there`s no practical application for any of this though *sigh*

it`s a real pity there`s no practical application for any of this though *sigh*

Isn't that sometimes the funny part of science ? Just investigating something out of curiousity...

it`s a real pity there`s no practical application for any of this though *sigh*

 

Don't be too sure. Google up on "acoustic emission". This technique uses a very sensitive microphone to detect chemical reactions involving phase changes, corrosion, boiler and structural member stress, etc.

 

Your method resembled acoustic emission, but it would be far cheaper and probably more sensitive for susceptible reactions.

 

Dangerous Bill