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How Do 'Singing Magnets' Work?
dpbsmith asks: "Singing magnets are available at all of the usual geek-toy emporia, and, for all I know, ordinary toy emporia as well. They consist of a pair of magnets made of a polished substance with the general appearance of hematite. What is surprising, pleasing, and unexpected is that when the magnets strike each other under their own power, they produce a sharp, loud buzz that rises in pitch. The sound lasts a good fraction of a second and climbs somewhere into what sounds like the 200-500 Hz range. The exact sound and its duration are somewhat unpredictable and depend on how the magnets happen to strike each other. It is a little like the sound that you get when you mash a pingpong ball against a pingpong table with a paddle. What physics are involved in the production of these sounds?"
"Google searches turn up some forum postings that indicate that it is a synthetic magnetic substance similar to hematite that's available cheaply in China as an industrial byproduct. The singing magnets are a little larger than size of olives; the shape is similar to a (U. S.) football but slightly more elongated. Their major axis is about 5 cm long, their minor about 1 cm. They are fairly powerful and will jump together when placed on a desk about three inches apart. They can distort the colors on a CRT display from a distance of over 20 cm.
Contrary to expectation, the poles of the magnets are oriented along one of the minor axes of the ellipsoid, not the major axis.
Neodymium magnets in 'ordinary' shapes produce boring 'plinks' when they snap together. Something about the shape of these magnets makes the sound much longer-lasting and entertaining. It is not simply the bounding rebound of two objects made of stiff-but-elastic material. Transfers of linear to angular momentum are clearly involved.
If course, I'd love to know whether these things were 'invented' or 'discovered', and by whom, trying to do what.
Contrary to expectation, the poles of the magnets are oriented along one of the minor axes of the ellipsoid, not the major axis.
Neodymium magnets in 'ordinary' shapes produce boring 'plinks' when they snap together. Something about the shape of these magnets makes the sound much longer-lasting and entertaining. It is not simply the bounding rebound of two objects made of stiff-but-elastic material. Transfers of linear to angular momentum are clearly involved.
If course, I'd love to know whether these things were 'invented' or 'discovered', and by whom, trying to do what.
They bounce apart, attract togethor, bounce apart again, etc losing energy each cycle until they can bounce no more.
Okay, that was a wild ass guess.
This is clearly the work of witchcraft! BURN HIM!!!
Despite what you say, they are just bouncing off each other. The modulus of elasticity is high, and because of the shape of the objects they can only contact at one point. The magnet pulls them together and they bounce apart, the point of contact possibly traveling along the curve of the objects depending on how much energy remains. They might maintain a semi-constant tone because this contact point travels to where the mass of the objects is less, at the ends, allowing them the bounce apart at the same frequency despite energy being absorbed in the material.
I don't have any so I can't verify this theory.
No make that scream...
I took the magnets out of an old SCZI drive bigger than my head, and pried them apart with a screwdriver.
Well I was holding a magnet in each hand, and while I was walking they got a little too close, and my was caught in-between. Oh I sang, like a little girl in church choir.
Long story short, I didn't need stitches, but I did have one very bruised bone, not to mention my ego...
Go ahead and call me unreliable; reliable is just a synonym for predictable.
It's definitely just them bouncing apart and colliding until they give off all their potential energy as sound.
If you listen, you can hear the pitch of the sound getting higher and higher as they start to hit each more frequently, until they stop moving.
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This is blowing my mind. You would think it should be a constant frequency with decay, like the classical pendulum. The difference between the classical pendulum and this case is that for a pendulum, the force is constant; with the magnet, the force is inversely proportional to the distance between the magnets. As the energy in the velocity (E=1/2mv^2) is converted to heat, the magnets have a lower velocity so they travel a shorter distance away from the other magnet. The closer the magnets are, the greater the force, again reducing the period between "clacks". The frequency increases because the magnets have a non constant in the force between them (the force increases as the reciprocal of the square of the distance).
.. it is the 'sound of the magnetism itself', which is to say, the 'out of balance' nature of the two magnetic forces reflective attraction for each other, pitched over time, much as a delay line, while things stabilize and the energy of the initial collision dissipates ..
; -- the corruption of government starts with its secrets. a truly free people keep no secrets. --
I'm sure that the guys who are selling audiophile lacquer for $200/oZ and wooden potentiometer knobs for $500 a piece will have a much more amazing explanation involving quantum audiodynamic subparticle field wavetransformation theory, that not only makes your audio equipment sound more open and free flowing with a nice improvement in resolution, better dynamics and improved overall naturalness, but also improves the taste of wine making it older in a matter of seconds (a widely known property of magnets), but I--a boring scientist--will only tell you this: they bounce.
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."
Ok, I'll probably lose mod points for this, but I can't be the only one to read that as "How Do Singing Midgets Work?" And here I was so excited to find out if singing midgets really do have to work harder to stay in show-business.
http://instagram.com/thephotographer
$1,200.00 is not that much for a high quality digital cable, but notice the arrows on the pictures. They indicate the direction in which the sound should flow. Of course it works best with quantum sound purifiers which strips electronic noise from individual electrons. When you are at it, don't forget to buy your tuning dots: "Marigo's VTS Tuning Dots have been one of the most effective and dramatic steps I have taken to improve my system's performance. The improvements were not sublte. They brought great transparency without losing musicality. Clarity, dynamics, inner detail, midrange bloom, bass slam and articulation have such an improved sense of openness that they represent a major paradigm shift in resonance control." Yes, those are little round stickers in various sizes that cost between $5 and $20 a piece, that you should stick to every single piece of equipment and flat surface in your listening room. It is not surprising that when James Randi offers them a million dollars if they can demonstrate that it works in a simple double-blind test (search the commentary archive for audiophile) they don't want it--if I was selling stones and sticks for thousands, I wouldn't want that laughable million either.
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."
I have a pair, and this is the only explanation that makes sense to me. I imagine that the effect would also happen on a whole range of rounded magnets of this type, but with the length of the "buzz" varying - the stretched football shape is probably just one of the more effective ones.
If you try to isolate the system by throwing them up in the air so they pull together and strike each other while airborne, they will generally buzz for quite a long time - generally, it stops because the motion was dampened by your hand (or whatever else they land on) rather than coming to a stop on its own.
The whole effect is made even more fun because if you throw them in the air, they will spin around each other like a cat in zero gravity.
Go here: http://liquidmetal.com/news/dsp.multimedia.asp
View their "Ball Bouncer Demonstration"
I have a hunch that these "singing magnets" are coated with a Liquidmetal-like material which preserves some 99% of the impact force and returns it quite energetically, causing the magnets to come together, be pushed apart, come together, be pushed apart, fast enough to create a "tone" of sorts.
When the ball gets to the end of the ball bouncer demonstration, it does largely what the original poster was asking about with regard to the sound it produces.
Reinvent the wheel only at either a lower cost, greater effectiveness, or your own personal enrichment and satisfaction.
"...simply plugging appliances into mains outlets in decending order of power consumption"
Sorry, that should have been "plugging appliances into power boards". Using different mains outlets around a room can cause the same ground problems. And always calculate the total loading.
Oh, and while I'm ranting: "Oxygen Free Cable"? If it's shiny, its oxygen free, you golden-eared idiots. Besides, most cable deteriorates because of chloride contamination from the PVC sheath, not because of oxygen (which is why we have "blackwire" syndrome; copper oxide is green, not black). And despite years of research, there is still not a shred of evidence that "microdiodes" really exist inside bulk copper.
"Sharpen razors overnight with a patented proprietary magnetic field. After each shave simply place the blade edge on the Razor-Mate. Razor blades are reported to last up to ten times longer, and give a smoother, closer shave." Looks impressive, but I only use free magnetic fields and I am strongly against field patents.
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."
they produce a sharp, loud buzz that rises in pitch. The sound lasts a good fraction of a second and climbs somewhere into what sounds like the 200-500 Hz range.
I also don't believe its a simple bounce. If that were so then it should work with any magnets with a a strong surface. I've never heard of this.
Someone pointed out that liquidmetal demos the same rising pitch behaviour. They do this by having an inredibly efficient 99% bounce. But singing magnets have been around for a while before that.
I think the shape allows the magnets to convert their kenetic energy into a rolling motion and back to kenetic without needing to to do a real bounce and avoid elasticity losses.
Think of Tony Hawks doing a half pipe. Vertical to horizontal back to vertical. The magnets with their weird shape collide slightly off center, then pulled by the magnetic fields convert a portion of their energy to the rolling that occurs as they get into a more parallel position and then inertia carries them beyond equilibrium where the kenetic energy throws them apart again. Like a rocking chair but with enough energy to seperate the surfaces. As long as the rolling resistance is low it should be pretty efficient.
Normally shapped magnets don't exibit the same behaviour since their surfaces collide and depend entirely on their modulus of elasticity to rebound them.
I not sure but I also think that the rolling action reduces peek force at contact so what bounce there is can be more efficient.
At least thats my guess..
You are unaware of the basics of metallurgy in steel, as well as of 'singing' in swords.
A properly made sword rings when tapped. This is because the fittings (hilt, pommel and handle) are tight, and do not dampen vibration. If the blade has any cracks, these will also dull the ring of a sword.
Additionally, a good western sword flexs a fair amount during cutting or thrusting. This in itself is not a positive or negative feature. However, a blade that returns too much vibration to the hand may be uncomfortable to use (think about how a bat stings your hands when you hit something with it).
The addition of chromium to a steel in quantities of over 13% makes 'stainless' steel. Not only does the addition of high levels of Cr make the steel resistant to stains, it makes in more 'deep hardening'. This is in refference to the cooling of steel from the the point at which all of the carbon in the steel is disolved in the solution(AC1, also called the Currie point, which is generally above 1350 degress F) down to below the point(MS, below 900 degrees F) at which martensite (hardened steel) is formed.
In this process, a variety of different crystaline forms can be produced. If you cool slowly, you will probably end up with pearlite. This is soft, and relitively flexible, and not at all good for blades. If you cool faster, you will end up with grains (crystals) of martensite, which is harder, and more springy (once tempered) much better for knives and swords.
Now, back to why stainless is bad for swords. Stainless is deep hardening because the chromium pins the edges of the grains (crystalline stuructures of carbon and iron), preventing them from growing when heat is applied. Smaller grain sizes lead to increased hardness. Unfortunately, the introduction of the chromium into the edges of the crystals causes them to be less strong. This leads to lower flexiblity. Lower flexility leads to swords that fail castastrophically durning use.
I'm not a metallurgist by any means, but I have made a half dozen swords, a hundred plus knives, and been studying heat treating of swords for about a dozen years. Please, spend 300+$ on good old fashioned carbon steel if you must have a sword. Heck, even get a good stainless steel sword from Rob Criswell or one of the Dawsons, but quite buying that cheap stainless crap on ebay and in the Mall cutlery stores. Support a sword smith with real talent, here in the US. There are lots of us, It's a better deal in the long run.
Josh Powell, owner and operator of Josh Powell Custom Knives.
I am sure that none of us would want to hear any jitter that sounds like ass--i.e. like this--but that doesn't mean that any of us would buy a $1900.00 USB cable. Also, the USB power is strong enough to power the iGrill (which is great, by the way, because now I don't have to carry around the bulky Zero-Point generator while I'm hunting when I have a laptop anyway), so we also don't have to worry about the power line impedance so much, unless we use kilometres long USB cables, which is not so popular as it used to be with null modems any more, since we have an easy access to the Interweb.
Now seriously, I have noticed that people usually stop listening when I start talking about the "science stuff" so they don't really care if it is Fourier series or quantum cleaning of dirty electrons, since they don't listen anyway. As long as it sounds scientific, it is scientific, for all they care. And of course I must be lying to them because I am only their friend while the guy who just sold them a wooden potentiometer knob for $500 must be an expert, because otherwise he wouldn't have a job selling expensive equipment, right? Here the cognitive dissonance kicks in: "I am not a sucker, but I have just bought an ugly wooden knob for $500, therefore people who say that buying ugly wooden knobs for $500 is dumb must be mistaken."
Now, when they say that it was an "expert" in the audiophile store who has told them--or the "expert" in the Stereophile Magazine who has written--what they are telling you about, what they need here is a good ipse dixit and argumentum ad populum, for they won't listen to any other argument at all.
At that point, I usually shout at them: "Does Deutsche Grammophon use this junk to 'purify' their music while they record it? No? Then why on Earth do you think I need it to listen?! Now, will you excuse me, I need to drink my snake oil," and I leave in furious anger. Later when I talk to them, they sometimes ask me: "Are you serious that the record industry don't use such cables? Why?" To which I answer: "Because they are not bloody idiots, that's why! Do you need to spend millions on sound equipment? Then go to the recording studio, see what they use, and buy the same stuff. You will still be a sucker to buy something that you don't need, but at least you will have something that actually works."
It is surprisingly difficult to explain the truth to anyone who have bought audiophile lacquer or the wine clip, but it is still nothing compared to e.g. homeopathy or any other quackery when we are talking about peoples' health and lives, not just some useless junk. People will just not accept that they are suckers. Remember this story?
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."