 The Clarinet BBoard
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Author: uliano guerrini
Date: 2000-12-14 20:03
I'm obviously kidding, there is no way for an acoustic vibration of a gas to produce elcetromagnetic waves... mhhh unless the gas is ionized??
anyway if you have access to a bass clarinet try to play a low note (Eb is perfect) and while playing look at the PC monitor (switched on!) (maybe it works also with the TV but I didn't try)
uliano
PS
I can only guarantee that with a NOKIA 447V the "funny" effect takes place
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Author: Mark Charette
Date: 2000-12-14 20:22
You get a beat frequency when you shake your head at similar frequencies to a TV or monitor's vertical retrace frequency.
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Author: mike
Date: 2000-12-14 21:46
Actually, any body at a temperature above 0K will emit a electromagnetic radiation with a blackbody distribution. For reference, at T=6800K or so, the peak of the distribtion is in the visible. At T=3000K, it has shifted into the infrared (about 10 microns). 300K probably corresponds to the range between microwaves and radio waves.
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Author: mike
Date: 2000-12-14 21:58
Well, ok, so the blackbody spectrum at 300K peaks at 18 microns. And thats still well inside the IR...
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Author: Mark Charette
Date: 2000-12-14 23:56
It's English, all right (all it boils down to is that any particle not at rest emits electromagnetic radiation - pun intended :^)
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Author: Willie
Date: 2000-12-15 03:56
If you are talking about the double vision while playing some of the low notes, I have experienced this on my contra alto also. Just about everyone says this is my eyes vibrating with the reed, but I'm not totally convinced. Last year I could see my neighbor watching the superbowl on the TV through my window. When a new play started, I blew a low F and he would get up a hit his TV almost every time. I did this for about 10 minutes. It was fun!
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Author: Mark Charette
Date: 2000-12-15 04:01
That's quite funny! Coincidence (unless there was a wire or part loose that vibrated in sympathy). The TV frequencies are electromagnetic, not acoustic, and a million or more times faster than the reed was vibrating.
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Author: mike
Date: 2000-12-15 06:21
Well, don't forget that AC power in the US is tranmitted at 60 Hz, so you might be able to see strange effects when you look at fluorescent lights when you play. Also, the effect with TV screens has more to do with the scan rate of the tube, which is something like 20-30 frame per second, than the actual frequency of visible light.
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Author: uliano guerrini
Date: 2000-12-15 06:58
mike wrote:
Actually, any body at a temperature above 0K will emit a electromagnetic radiation with a blackbody distribution.
sure!! how could I have forgotten it!!?
would you please be so kind to remember me the field strenght in V/m so I can sue nokia engeneers for declaring EM compatibility.... (grin)
uliano
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Author: Gordon (NZ)
Date: 2000-12-15 10:18
Mike: In English he was saying that anything with any warmth at all gives out warmth. Aint that profound! (He is telling you that he knows that the warmth given out is part of a group of 'radiation's called electromagnetic radiation)
And the discussion was confirming that the warmth given out is indeed perceived as warmth given out (as opposed to other forms of 'radiation' such as light rays, microwaves, radar waves, xrays, radio waves, nasty rays from bombs and nuclear power stations, rays for killingf cancer, rays for causing cancer, etc) And that was also profound!
(Just stirring!! 
By the way those weird screen effects can also be achieved when sitting on one of those vibrating massage cushions or chairs.
A TV screen jerks if your bang your head.... same sort of thing.
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Author: Jodi
Date: 2000-12-15 12:39
I think that it's just the vibrations from your head while you play. I have found that on occasion, blowing a raspberry (you know, the Pthbbbbbbbt sound) with your mouth and looking at a computer screen will make it bounce....
I can't explain the superbowl. That is the kind of fun I would like to have though.
~Jo
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Author: Dave Spiegelthal
Date: 2000-12-15 14:34
It's true. Frequently when I play bass clarinet, the navigation systems and radios of commercial aircraft flying overhead are disrupted, and the aircraft crash into fields near my house. So I try to do my practicing during the late evening, when there are fewer flights, to minimize the number of catastrophes.
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Author: Stephen Froehlich
Date: 2000-12-15 15:09
I remember maiking my monitor jump when I first started playing around with the contra-alto (high school). I'm pretty sure that something really happens in the monitor, as I remember bringing other people to see the effect. Concert F or E was the most effective note for me to get the monitors to skip. I have never acutally bothered to speculate.
Just for clarification's sake, this has nothing to do with the blackbody radiation of the clarinet, as its blackbody radiation is essentially the same of the wall behind it.
OK, so why would harmonic acoustic waves kill the horizontal sync of a CRT? The only electronic parts that respond to physical motion are inductors (electronic elements that use magnetism). A TV tube is full of them, most espically the flyback transformer. Transformers actually try to move (torque) due to the magnetic-electric interactions (hence the 60 Hz buzz from them). Given that the assembly of a flyback transformer in one's TV is usually farily loose, the acoustic vibrations could modulate a transformer so that its out of sync with the rest of the electronics, hence causing beats (yes, the same ones that tell you you're out of tune) which show up as horizontal sync "rolling".)
Hey, but who am I?
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Author: Stephen Froehlich
Date: 2000-12-15 15:20
One additional note, the TV thing looks very much like what happens when hsync is not correctly adjusted (roll). It is on a much larger angular scale than the double vision from your head vibrating. Moreover, the double-vision thing when combined with a TV scanning at the same frequency would cause effects like seeing the edge of the screen over the plastic, etc, not the hsync thing.
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Author: uliano guerrini
Date: 2000-12-15 18:14
Stephen Froehlich wrote:
>I remember maiking my monitor jump when I first started playing around with the
>contra-alto (high school). I'm pretty sure that something really happens in the
>monitor, as I remember bringing other people to see the effect.
I disagree, or at least we are not speaking of the same effect: captured my wife and coerced her to play the low Eb ... she was seeing the effect... and me a still monitor... so, unless the contra can foce other people head to vibrate syncro, ...
>OK, so why would harmonic acoustic waves kill the horizontal sync of a CRT?
>The only electronic parts that respond to physical motion are inductors
>(electronic elements that use magnetism).
I disagree... capacitors can respond... you know some mic are just capacitors...meanwhile I can't see the electric effect of a mechanical vibration on an inductor or transformer
magnetic field generate forces on currents in wire so they move and create the pressure waves known as sound (noise) this is NOT reversible :-)
uliano
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Author: Mark Charette
Date: 2000-12-15 18:23
Besides being totally off-topic ...
The screen flickers. Your head shakes. It ends up being a stroboscopic effect - your visual system starts seeing what's _really_ there (a flickering TV screen). TV and movies are "unreal" in the sense that they only show single frames, not continuous motion. They're an optical illusion. A valuable one, but an illusion nonetheless.
Enough on this subject. It's a joke gone too far afield now.
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Author: uliano guerrini
Date: 2000-12-15 18:23
Dave Spiegelthal wrote:
>It's true. [...] to minimize the number of catastrophes.
:-DDD ROTFL
ok thell me were do you live ... in case I should ever fly there I will do the last 100 miles (will be enough?) with a public car (hopin' you don't interefere with the ignition)
uliano
(who fears flying)
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Author: Rene
Date: 2000-12-18 12:21
Just one more, please: Could it be that those virbrations have negative effects to the brain too? In the end, things may start to look spooky, not to mention the danger of getting addicted. God, I have been playing too long.
Rene
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Author: Mark Charette
Date: 2000-12-18 13:55
Actually <i>that</i> is a more interesting question. I have not looked for any studies referring to the effect of low-frequency vibrations to the brain. Perhaps someone can do an article search at a library to see if there have been any studies.
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Author: Gordon (NZ)
Date: 2000-12-19 08:29
The vibration mayb help to make lateral thought connections. Just think of all those nerve endings flapping around and making new links!
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