The Barkhausen effect 

Do you have any further ressources on that? I unfortunately failed to find anything and wondered how a practical implementation into a radio receiver could work.

@@GreenCaulerpa I think the book "Early Radio Wave Detectors" might have been where I read it. In the early days of radio communication, it was desired to receive a single click from a spark at the transmitter. I think the Marconi magnetic detector might also have used the same principle, with a moving iron wire.

Yea the go SS IP for the flap and jacks on winder association of people who FLAP A B,OUT ANN HOT P LATE ITS CALLED POLE HATE HE KET

Shut up nerd

When you do not lift the needle from a record at the end you can also hear a hiss and a click

yeah 😅

Using

@@garyfrancis6193 no, usage

@@garyfrancis6193 It works both ways

@@arandomyoutuber6634 Wrong.

“Using of the brass bolts” is grammatically incorrect. there’s no room for debate, this is fact

Yeah. This demo really "clicks"!

Yes it is! Flashback of collage physics class poped in my mind and I visualized how the domain rub agains each other. 👍🏻

This is definitely a thing! Connections Museum has a whole video series on this very concept, the ringing machines used for telephones back in the day. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-dqKFS1p1ivo.html

Badass

This is how electric guitars work, but instead of a spinning square, it's a metal guitar string vibrating elliptically.

@Darrell Pidgeon so it seems reluctors actualy came from that design/mechanism

As found inside Hammond tonewheel organs

I'm glad you mentioned that. I was thinking the same thing.

Try putting your phones speaker up against the pickups while playing music out of them. The pickups will actually pick it up, because they are responding to the moving magnet of the speaker driver! Super cool.

Well it Is from ten years ago lol not these content farm junk videos we are inundated with these days

386 chip inside as the preamp/amp ?

Priceless 🤣

Man🤣🤣🤣🤣🤣🤣🤣

It's almost like a rain stick where you're hearing the atoms realigning. Fascinating.

name the 1001st

Battery powered, so no connection to 60 Hz AC.

@@akulkis Ahh! That makes sense! But . . . I had a wired earbud; no plug, just two tinned wires. Touch the wire to anything, even your skin, and the earbud would roar with sixty Hrz. RF. That said, this was very interesting. Thank you.

@@akulkis It has nothing to do with the power supply, the 60Hz hum is picked up from externally generated fields like florescent lights and computer monitors. All coils pick up noise unless it is wired to a second identical coil of opposite polarity to cancel out the hum.

Mostly not heard because of the tiny speaker in the test amp and weak path to built-in mic on camera. I'd like to hear the coil hooked up to a direct connection in the camera setup.

For that noise to disappear, nothing special need to be done. The orientation of the coil axis must be changed until the noise disappears completely. I know this because I did the experiment.

shit, they got him.

Magnetite, magnetic iron ore. Deposits in many places, Atlas mountain range I believe is one example

@@tsm688 Your, sir, win the Internet today!

I second that win, it made me. Lmao🤣

People saying it sounds like sand tripped the kitty litter algorithm.

Correct about the Faraday Effect! Yes, it's voltage that is induced in the coil, but in this case there is also a small current flowing, because the coil does have a load - the input impedance of the amplifier.

What a load of.... jk😉

Видимо магнитные линии толшиной с пищинку песка

sounds like radio static to me

@@alexprost7505 😃👌🏽

Yeah. Of course we don't directly hear the magnetisation. The effect attempts to demonstrate the irregularities in the magnetisation. The jumping, as you say.

Please do!

It doesn't magnetize the strings, they do not exhibit magnetic attraction and cant even pickup iron shavings unless physically touching magnetized pickup polepieces. They physically move in the complex magnetic field around the pickup.

@@JohnSmith-fq3rg How does just moving a piece of metal around in a magnetic field affect it, assuming the metal is not being magnetized? I guess the string then could be part of the core of the inductor, and moving it would change its inductance? But there's no currect being supplied to the guitar so any current to the amplifier must come from the guitar itself.

@@stekeln I don't know much about guiters but I think the strings are made of weakly magnetic material like steel or sth. Thus a tiny voltage change is generated in the pick coils [due to perturbation of the magnetic field of the pick] this then gets amped. The picks have magnets in them, no?

@@rex-up9ln Well, magnetic fields can't be "perturbed" so to speak. They are additive so in this case the magnet(s) in the pick-up would be completely unnecessary since it's not moving (in relation the the coil) and so could not generate any electricity. The only thing that could do that would be a moving magnet, the strings. If guitar strings were magnets themselves, the pick-ups would not need to have magnets.

@@stekeln 1. Perturbed in the sense "disturbed from its original state", i.e the static fields around the permanent magnet. 2. See en.wikipedia.org/wiki/Pickup_%28music_technology%29 my guess was correct, there are coils wrapped around permanent magnets and the strings are ferromagnetic

It’s not individual atoms switching, it’s magnetic domains

@@1495978707 Correct ! And if the ferromagnetic core was thinner, for example a transformer sheet, you could hear pops due to the change in the orientation of the magnetisation of the domains.

@@My_Fair_Lady Me, a liar ? Then Richard Feinman was the same, because I was inspired by his books when I did the experiment ! The domains of magnetisation are large enough to be seen with an ordinary microscope, so the sudden change in the magnetisation orientation of a single domain induces a detectable current in the coil. The phenomenon is observed at the beginning, when the external field is not to big.

@@My_Fair_Lady Feinman's postulate ? Here we are talking about experimental observations, not some postulate ! And I repeat, I myself did the experiment with devices made entirely by miself and I know what I observed !

@@My_Fair_Lady "Myself", sorry ! I live in Romania 😃 and I didn't learn English at school, I use google translate more ! I know wery well what I heard ! The sand-like noise heard in the video above is produced by the changing magnetisation of many Weiss domains. If the ferromagnetic core is thin and if the magnet is not too close to the coil, you can hear the change of orientation of each individual domain, that is of the more "sensitives" ones, which are fewer. As the magnetic field increase, the noise will resemble the one heard here.

😆

BOOOOOO

Do it... then post it... & share your link👍

My opinion is that it would be the same thing, a ferromagnetic single crystal is composed of many randomly magnetized domains, because if it had the same direction of magnetisation, the crystal would be a magnet !

The thing that this experiment is historically said to have proven is that the metal is built up of individual Magnetic domains (Weiss domains) So theoretically it should make a fundamental difference.

Mössbauer !

It's called Schrödinger effect.

@@oscargr_ There is no Schrödinger effect in physics ! There is instead the Mössbauer effect.

Rabbits don't have anything to say but they sure listen!

@@marianl8718 oh, killjoy

The potencial (voltage) amplitud at the coil is proporcional to the number of the turns, more turns more voltage can be enter to the amplifier.

Thank you, and you're welcome!

Good question. Surely the rod at different depths would make a scalable difference of some kind, trombone-style. Also, if you held the coil up to the amplifier speaker, would you hear a) nothing, b) similar white noise, c) same as magnetic rod, d) feedback [tone], e) other??

I think the effect might be weaker as the magnetic domains in a magnet are already oriented?

@@chriskaprys depends. Practically very low feedback. Feedback is due to coupling of the coils

From its apparent size and the length of wire, I'll wild guess in the neighborhood of 100 millihenries

It produces a white noise. The coil / parasitic capacitance is a tuned circuit, and will act as a bandpass filter in the audio range if you visualise the output on a spectrum analyser...

Who r u?

@@zhuzhu9599 the creator of the video

@@myrealusername2193 And why are you gae?

@@myrealusername2193 10 years ago

Yes.

A good way to visualize it is puzzle pieces with arrows drawn on them. When you put iron puzzle pieces together all the arrows point in the same direction. When you put chromium puzzle pieces together the arrows alternate. Mix them together and you get mixed magnetic domains making the strength of the field weaker. All matter is magnetic, but some matter cancels its own magnetic influence.

Its a Theremin. Objects near the antenna cause beat frequencies in the audio range by changing the frequency of radio waves so they're canceling and reinforcing such that a tone is produced. There is an antenna for both frequency and volume. Lots of videos here. Clara Rockmore was a contemporary of Leon Theremin ; it's inventor , and plays classics. Her videos are here , as well a lady that does it today. Page used one in Led Zep. I made the PAIA kit back in the '70s; lots of fun. I think someone still makes them.

Why don't build an experimental setup yourself and find it out? I'm gonna do it when I have time.

LoL

To answer your question, no. An MRI scanner is essentially a nuclear magnetic resonance device, it uses the fact that nucleons (what an atom‘s core is made of) show a characteristic we call „spin“ which is essentially the angular momentum of these particles - except they don’t „spin“ in any common sense. Since protons not only have a spin but are also charged, this results in them having a magnetic moment as well. Essentially nuclear protons act as teeny tiny magnets. If you apply a magnetic field (the big ass superconducting magnets in mri devices) these spins will align themselves either parallel or antiparallel to the magnetic field lines. But due to heisenberg‘s principle you cannot know both the exact location and impulse of a particle with absolute accuracy at the same time, so it essentially has a spin precession around an axis parallel to the magnetic poles - very much like a spinning top would „wiggle“ before it falls over. Now an external electromagnetic field is applied with a resonant frequency, this will essentially pull ALL the magnetic dipoles to one side. Now they can be seen essentially as rotating bar magnets. Since rotating bar magnets can induce a current in another coil, we can pick up their signal. For mri we use the fact that not all isotopes are nmr active and that other active ones have different resonance frequencies so they don’t get in the way with our measurments

Or shorter: No, the human body doesn't contain that much metal. (In fact if it did, it's not advisable to get in an MRI)

@@oscargr_ In theory every paramagnetic solid could exhibit something like the barkhausen effect due to the formation of magnetic domains (although muuuch weaker). If an atom or molecule is paramagnetic or diamagnetic depends on the existence of unpaired electrons (electronic configuration). Even bimolecular oxygen like in air is magnetic, so is manganese(II)sulfate. You are ultimately right in the conclusion, but you wouldn’t have to be made out of metal for that

@@GreenCaulerpa Thanks for the reply, I kinda understood what you are saying and it makes sense. I have a buddy who's doctoral thesis involved MRI's and the doppler effect so it would be possible to track blood flow and movement within the human body in real time. He was pretty good explaining things but I wasn't very good at understanding them so I would save him time by trying not to ask him questions I couldn't possibly understand, only that thing where you don't know what you don't know kept popping up, lol! Still, I find the overall concept of MRI's and that technology to be absolutely fascinating. I guess because it involves a method of seeing things that is so unlike image projection onto a plan, like the way film and optical image sensors work. Maybe if I am lucky, I will never understand and the awe of the magic will last forever. :)

I imagine that is because the magnetic domains in harder iron are smaller.

@@oscargr_ I suspect you are right.

That is correct. It creates a circulating electric field, which will drive a current if there happens to be a circular wire in that location!

Not sure? If there's a carbon steel rod inside a coil, that would probably enhance the magnetic flux in the coil, but haven't looked into it in detail.