I really love when reality trumps common sense. At the beginning, I considered the dangers being raised to be very, very plausible. As you began to test them out, I was cringing inside, waiting for a strong reaction leading to disaster. What a cool video. Thanks so much!
B75; You are going to get in the center of the magnet. Magnet; na, I don’t feel like it. B75; I’m telling you, get there, now. Magnet; I told you that I don’t want to. B75; I don’t care what you want, right now. Go! Magnet; make me. B75; goooo Magnet; clump B75; come on back, let’s try it again. Magnet; no, you can’t make me. B75; come on, I’m tired of this. Let’s go. Magnet; nnnoooo B75; oooooooooooooooooo, that’s it don’t make me come back here with my stick. I will do it. Magnet; mmmhh B75; you have till the count of three. One, two, Magnet; you will not make me move. B75; come on, I got you. Come on. B75’s back; this is tough. I don’t think it wants to come. Let’s give it a minute. B75; no, I aallllmmmooosst have it. Come on legs. Put some work in. Magnet; nnnnnooooon nnnooooonnnnooo B75; ooooffff, I got it.
Let your heart be your compass and knowledge be your candle. We won't get lost, love always wins. It might take lifetimes but it will win. One love, one family, one planet and only one you!
5:30 there are safe shoes without steel. For various reasons, steel is now being replaced with other material. The root issue is that steel is a shape memory material, and we now prefer that, once the deformation point is reached, material do not bend and punch the foot with permanent memorized pinched, but we prefer the materials to just break. Broken shoes are easier to extract. Pinched shoes are very difficult to remove at hospital, and once you know the energy involved passed any reasonable value, doctors prefer removing parts of shoes rather than having to grind steel literally glued to skin. I don't know if materials are derived from plastic, glass, or carbone.
that and steel is expensive, random other materials are cheaper to produce so therefore bigger profits for the companies. Steel toes are superior in maximum performance but honestly if you're dropping nukes on your toes, you're doing something wrong.
Carbon Fiber, Fiberglass, and various polymers are pretty common. i think the CF and FG would be the best options since you can actually wrap them into the sole a bit to create a sort of toe box that's much more durable than just a toe lid or toe hat.
Actual steel toed boots are indeed getting more rare. Since they are frankly worse. (some insurance companies don't even regard steel toed boots as safe, and won't cover medical costs if such were used.) Composite shoes with fiber glass, carbon fibers, or at times Kevlar are all more light weight, non magnetic, and cracks when overburdened instead of deforming. It is far easier for crushed toes to heal if not encased in a few mm of steel. And a lot of composite shoes are even stronger than steel ones, especially as far as weight is concerned. Composite shoes are though typically more expensive than steel ones, since making composites is more labor intensive then forming a piece of steel. (and steel is also cheaper than composites from a raw materials standpoint) There is also plastic reinforced shoes, these are also much cheaper than steel, however less strong. But for a lot of lighter applications these are strong enough, while having the advantage of not encasing toes in hard to remove material.
@@GameTimeWhy ... based on basic materials science? you fucking spergerstein? If carbon or plastic was better than steel, they would use those to make buildings, not steel beams. The two problems of steel toes is weight and irremovability once it *does* get crushed. But it's yield strength is the highest of all other offered materials.
@@awesomeavis7861 Because both are round, there's literally a point contact and it's hard to see in motion. But they're definitely connected at all times.
I think we would either need the raw uncompressed footage or a slow motion camera to confirm this, the problem is that if the plates would seperate, the Magnetic force would decrease by the square of the distance, and the centrifugal force would increase as they sepperated, and because they are not connected and no change of medium there should only be a decrease in magnetism as the magnets begin to seperate. After reviewing it in this fasion, I too believe its an illusion created by video compression and or the camera itself. I do not think they ever sepperated, and if they did, it would be Very brief and as a result of vibration, not centrifugal forces, soemthing that only a slow motion camera could catch it.
"Remember to like, *and maybe even subscribe* " That's some good ol' fashioned humbleness right there. I respect youtubers who don't throw the request in your face, or try to guilt trip you, ect. Your content is very reliably good, so a sub is a no-brainer. Keep up the good work!
Yeah, you came up with the same explanation I did, essentially. You put a ferromagnetic material up against a magnet, it becomes a magnet itself. Which means for long objects, the far end is the same pole as the face of the magnet and they'll repel each other. This is why paperclips stand up. For the lying flat scenario, you'd have to absolutely perfectly center the weight under the magnet and have it be perfectly parallel to the magnet as you bring them together. Any variance at all would cause it to polarize the closer side as opposite to the face of the magnet and the far side the same, force it it upright.
Yeah your explanation sounds correct, it's exactly what I was thinking when I saw the weight flip up and the two bottoms instantly repelled one another.
You just explained it by yourself: Ferromagnetic objects try to align alongside magnetic field lines, which are vertical at the magnet center and horizontal at the edges.
I think it looks strange enough even when you know there's a magnet. And also I think it would be impossible to see without realising that there must be a magnet.
Brilliant! 😀 the clip of you doing the reverse weightlifting gave me great laugh. Stay safe and remember to degauss your weights before your next session 👍😀
Damn. That's a nice question. Got me thinking... This is my take on it 🤔 I'd think it would still be the same. Though the fieldlines at the side are more going sideways and to that are more dense. So adding a flat metal on the left side, many field lines pass through the left side of the metal in an almost parallel manner to the metal. Only few field lines are in the opposing direction on the right side of the metal. So I'd say, the left sides attraction overpowers the repulsion of the right side.
Maybe the weight ‘conducts’/refracts/redirects’ the field lines convergence points. If each line has areas of N and S along it…then perhaps it could be that as these parallel lines approach so too does the attraction between them.
I am taking a Physics class right now and the one thing that my physics professor would say is that there are no monopoles. When you magnetize an object (or creating a temporary magnet by introducing the iron to a magnetic field), you are creating an object with both a South and North Pole. The paper clip and the weight do not want to lie center of the magnet because their temporary poles are repelling them against the magnetic poles. This causes them to align themselves with the magnetic field in the direction with the largest decrease in magnetic strength, in this case vertically. At the edge of the magnet, there is a large decrease in magnetic strength between the center and outside where that magnetic field curves from parallel to the edge to the center of the magnet. The induced magnet in the iron makes it really easy to align the metal to the edge of the field.
I get in enough trouble with small Neodymium magnets. You can also see this in the videos of MRI magnets that are being decommissioned. The various metal objects released near the magnet stick out instead of being pulled flat against the magnet. Search _magnet quench_ for hours of entertainment.
@@hughbrackett343 I was less worried about he LN2 and more worried about the straight O2 mixed in there as if you were doing a quench in a true emergency, I think liquid air is a flamibiblity hazard. I'd hate to hear about a piece of electronics getting sucked onto a patient so they quench and a fire breaks out in the room... that's nightmare fuel
I recognized this phenomena over a decade ago, using things like paper clips, nails, and other objects. Your graphic explanation is exactly how I rectified it in my mind back then, so I believe you're 100% correct in your analysis. Now, where things would go terribly wrong, and you would lose digits or eyes, is if you tried putting another similar magnet under the table! Then things would happen exactly as others feared, and it would snap flat and center, or if two, they would snap together in either direction dependent upon certain variables. Needless to say, it would be foolish to even try! Absolutely love your videos... Edit: btw, I'm guessing you can take those washers or paper clips, and easily lay them flat along the edge of the magnet face...
Lovely, These videos are always so entertaining and I can watch hours of this stuff , in fact I liked it so much I have some strong magnets of my own! (weak to yours lol) and your explanation seems correct one of my favorite videos.
I would be interested in seeing you test the snap force, using a hand/finger made out of ballistic gel & bone. A good visual of the possible danger to hands/fingers.
The explanation is very counterintuitive to what most people understand about how magnets work. A number one rule in physics is that magnetic fields can't do work. On its face, this seems to fly against everything we know from practical experience. However, what generates the forces that we normally experience when we play with magnets is actually the magnetic field gradient. In this case, your supposition is correct. When the dumbbells are oriented edge on the gradient is very strong, which induces a very strong corresponding magnetic field in the iron. This feedback pulls additional field lines in until it reaches equilibrium. When it's parallel to the surface though the magnetic field gradient is very weak, and therefore induces a very weak field in the iron.
I experienced this phenomena about 30 years ago. I played around with my keys outside a NMR cryogenic magnet and discovered that the keys were pulled towards the magnet along the magnetic field lines, but following the lines around the keys now pointed away from the magnet while pushing against my finger... I kept a very tight grip of the ring holding my keys. :-) To explain any physical system, just look at the energy in the system. For this case, when the object aligns along the magnetic lines the energy is locally minimized. If you want to turn the weight there is a energy penalty to overcome. If the system is in a stable state you have to add energy (force x distance, poking with a stick) until you reach a maxima and the system can drop down into the next minima of the system. In my example of the keys and in your video it means that the object is in a local minima and can't turn as it requires more energy than the system possess. Adding energy in the form of violently shaking things could bring a system from a local minima into a deeper global minima. The other way around is harder. I've been too long-winded, so I just say, Nice video! :-)
This is because of the Demagnetization Field. This term and its explanation can be found in litterature and in most books on magnets, like Blundell's book on Magnetism. In this example, when a magnet is flat in one dimension, the H field between the two imagined "Magnetic charges" on the top and bottom layers cancels out the Magnetization field, M - because they go in opposite directions. For long objects, the "magnetic charges" are far away from each other, thus the H field inside the magnet is small, and a large Magnetization can occur inside, which was what your simulations showed. When simulating and calculating this effect, you will need to specify the Demagnetization Tensor, which gives tells how much the magnet Demagnetizes itself in different directions - the shorter the magnet, the larger the Demagnetizing effect.
The easiest way to analyze it is probably in the context of equivalent magnetic circuits. I don't have too much experience with them, but I believe what's happening is that the weight is moving into the position which minimizes the magnetic reluctance. There's a lot of good info online about magnetic circuits.
It's so counter-intuitive because just looking at it, we assume it to behave like gravity, which (I believe) behaves in straight lines. But magnetic fields aren't straight lines, and the poles don't act like mass.
whats interesting to note is the weight reduction while under the effects of magnets while swinging. if polished surface might swing for every. great content sir
Great video as always. Like others in the comments, I would enjoy seeing that magnetic field program depicting a flat weight offset from the center of the big magnet, for comparison, if that is possible.
Your theory makes a lot of sense to me. I have a theoretical experiment that could be performed in order to test the theory. Place the magnet so that it is at a 90° angle from your usual positioning on top of the table. Slowly bring the barbell weight towards the bottom of the table first in the usual perpendicular to the ground and then parallel to the ground. And we'll see which orientation has the stronger magnetic attraction.
It has to do with the shape of the magnetic field. It's stronger near the edges and in the center. Depending on polarity, the field will flow up from near the edge on the face of the magnet, and flow towards the middle, or the other way around. This means that it wants to "short" the magnetic field through the metal you use. This poses a few different issues: 1: the material is saturated by magnetism, and is partially attracted to the magnet, but also repelled, much like the experiment of having 2 metal strips hanging, charged at the same high potential will repel. 2: for the weights with a hole in the middle, you'll likely still have the same issue as above, but it's likely made worse by the fact that you have a hole in the middle, where the opposite polarity to the edge is. If you had a thick cylinder without a hole, that has enough mass and capacity to not be saturated by the magnet, it would likely happily stay in the middle. If it does not have the magnetic capacity, a chunk of metal that big, might just flip the magnet in stead.
Within the magnetic field of the neodymium magnet, the weight becomes its own magnet. I my opinion, it's a question of geometry. The same poles on a magnet want to be hella far from each other, so any object placed towards them should line up in a stable and long orientation.
When i think about it, all i could think of is how the magnetic field spins around its edge and go through the center densely and straight down, therefore grabbing the also-vertical magnetized object in a better position. It seems i was kinda right, but thanks alot for the color/visualization of it! 👍
I like your other videos where you respectfully warn viewers of the various potential hazards associated with the content, but never assume that they are not capable of coping with them on their own. I click away from other videos when they assume somehow none of us are as capable.
I am amazed at how little we understand these things. We can describe them so accurately, but no one can explain a "mechanism" of cause. That kills me, and most don't even see the difference between "what" it does and "why" it does it. And then, magnetic lines do not exist, but most people think they do. The lines come from our attempt to describe and visualize, but the field itself is smooth and homogeneous. The spikes in the fluid come from how mass channels the field around other mass, not from the field itself.
The way I look at it is that the permanent magnet induces a dipole EM field into the iron weights, and the most stable self-organizing configuration is where the poles of that induced field have the maximum possible separation. Pushing the weight flat forces a metastable state around a local potential mimima and the quick flops represent the local maxima where the configuration slips from one energy well to another.
It's a function of the Surface area that interrupts the magnetic field, and total distance the field has to travel through the material, and the material's magnetic permeability. Think of how magnetic chucks for CNC machines work.
In any arbitrary configuration of magnets and ferromagnetic objects, the force always is in the direction that increases the total magnetic flux. The flat disk of iron on a pole increases the total flux just a bit, but any tilt increases it even more. So the flat approach is not stable. If the disk were perfectly constrained to move only along the axis of the magnet, it would be weakly attracted. But the slightest tilt would produce force that increases the tilt.
During the video, my speculation was also that it had to be related to the direction of magnetic field lines, where the illustration with a paper clip is more illustrative with the much larger size difference, that it is actively pushed up. Appears that the magnet does not like the lines "trapped" in the metal object being bent too much.
I was about to write something "because in a flat position the field would become an unstable mess", but you've demonstrated it in a sim. The magnetic lines that would form in a pancake will not form a good magnetic dipole, instead having poles scattered as rings god-knows-how. There is a big difference between being a magnet, which is best flat, and being magnetized. The reason there is no scientific papers on that problem is probably because it's quite straightforward. It's enough to consider 2 things: 1) Magnetic field can represent potential field by sort-of-inversing curl. 2) Everything in mechanics wants to achieve the maximum drop in potential energy possible, given the initial conditions (see Euler-Lagrange equation). Or everything follows the path of the most drop in potential. From those two, an axis aligned flat object on a magnet would experience the least possible potential (field) drop. There are neighboring positions with higher drop and the object will try to jump to them. This is as plain as putting two spheres one on top of another: the position is unstable and the top one will roll down. Lying flat off-axis over the edge of the magnet is also stable, although less stable. That creates a crisscross pattern for the poles in the magnetized object where the hanging part of the object is attracted to the side of the magnet, because it is polarized in reverse and wants to attach itself to the side.
i've always known objects will be forced into alignment with the magnetic field's directions, but i've never really thought of it this way. its the same reason that when you sprinkle iron dust on a magnet, it doesn't all clump tightly to the magnet and instead forms peaks along the field's vectors. there is probably a formula correlating magnetic flux vs moment of inertia in regards to the shape of things and their mass being affected different ways.
Maybe you could make video where you heat the weight and let it cool while still in the magnetic field? How strong a magnet can you make with your super magnet ?
Magnetic shape anisotropy will always prefer to magnetize the material in the longest direction possible. There will be less domains compared to other directors and will always be the case unless you're dealing with single crystal materials
8:25 it has very high "flux density" if you sprinkle more paper clip on top (or better still, tilt the magnet on it side) with a piece of paper, it no different if you sprinkle iron powder onto a paper with a smaller magnet underneath, showing the "pole orientation pattern".
I wrote a 10 page assignement on magnets a while ago. Your explanation as far as i know is correct. Though the resistance to flipping aweight is not only due to the repulsion but also because you move the weight through and out of the fieldlines. Though i'm not a 100% on that part.
I think it's that the weight becomes a magnet and it tries to keep the same pole away from the magnet. I bet after this the weights are slightly magnetic from being in such a powerful magnetic field.
In fact used fitness weights are often spontaneously magnetized due to the Villari or inverse magnetostrictive effect, because they're banged around so much.
@@ldskjfhslkjdhflkjdhf The Action Lab did a video not long ago about tapping iron to make it magnetic. Check it out: th-cam.com/video/oNjMLtHFxkU/w-d-xo.html - Can You Magnetize Iron Just By Tapping It? It works when tapped by aligning magnetic domains in the metal to the earths, or other strong nearby fields.
@@Muonium1 yeah, I know about the Villari effect (plus it's mentioned in the comment I replied to), I'm talking about information on weights specifically being magnetized. I can't imagine the stresses on gym weights are distributed uniformly enough to cause them to become magnetic to any significant degree. Plus the weights are so big. I found the claim surprising and was hoping you had a source or something you were drawing from
i just BURST out in lauthter at 5:12 - no joke you're a creative t(h)inker :D and i havent even finished the video yet! this is why i love your channel!
I don't know much about permanent magnets other than the iron filings experiment I did in school (well also things like the curie point and stuff) though I was about to sketch out the exact same thing in your simulation. It's easier to picture in my head but because the field lines extend out almost perpendicular to the magnet they'll 'interface' better with perpendicular objects. Edit: You explained it better.
When the weights started swinging at around 3:41 it appears that the bottom one separates for a moment at every swing before been pulled back by the magnetic field. Was that so or was it just my impression?
iron is not only attracted to a magnet, but it also becomes a magnet itself. It couples to a nearby magnet and reshapes the field giving rise to another pseudo N & S pole. I've been loosely trying to make formula for this.
One aspect of the geometry you didn't explore further was that all of the pieces you experimented with were toroidal (have a hole in the middle). That air gap may also play a role in the magnetic fields preferred pathway. It may be easier to center a solid disc vs a donut. I still believe the preferred orientation would be to hang but it may not snap off center as consistently like the barbell weight.
So, I'm at 1:00 even, and my guess is that it's the same thing keeping us from evolving wings, and from free energy. The universe seems to like the lowest possible energy state, and it seems like gravity pulling on the weights effectively cancels out the "desire" of any given weight to flip up, like a ball trying to roll uphill. Yes, there's plenty of force there, and yes it's a more stable position to get to flat with the magnet, but doing so requires overcoming gravity. Same goes for the other magnets, as they're held up from the conducted magnetic field through the weight above (kind of like a "lense" for the magnetic field, it's strongest on one pole where it's closest to the magnet, which means to me it's strongest on the other at the exact opposite point), kind of like how transformers have an iron core to increase efficiency. I'm not a physicist, mathematician, or anyone qualified to talk about any of this. Just my pre-video guess. Excited to see if any of this is brought up
What was interesting was how instantaneous the weights jumped into position to align themselves with the magnetic field, as if their mass was completely negligible. Did they even conform to the standard rules of inertia and F = ma? From the video you could estimate the force on the weight to make it jerk move that fast (and jerk to a stop).
nono..it appears right...it was more or less exactly what i thought would apply. many thanks for your work. the channel is truely, a great source of knowledge :3 stay safe :3
I'm curious to know whether the geometry of the Barbell weight plays an additional part to the story; in your simulation you've treated the weight as a solid mass where the north and south poles will be orientated at opposite ends, but in reality the barbell is a Torus, is it possible that the magnetic field is aligning with an opposite pole on the internal curve?
Thanks for showing all this neat stuff. Could you please do a video where you show the magnetic axial flux lines with ferrofluid, and then rotate the magnet around that axis? This would visualize the Faraday paradox, that still today isn't fully accepted or understood. A rotating stand with a monster magnet on top - a glas bowl of ferrofluid would do the trick? 😇
Individual magnetic field lines extend between north and south in concentric torus shape. Your iron is attracted srrongly to the flux in one magnetic field line at a time - linking/unllinking field lines has a canceling effect.
Consider a rod with two ferromagnetic spheres on each end and a pivot point between them. -Introduce a magnetic field in the form of a dipole magnet. -Influenced by this external field the spheres will find the internal field that minimises the torque about the pivot. If not for gravity the rod would be tangent to the external field. -The other state, is when the magnetic restoring torque, is cancelled by the normal force of the table. -The inflection point, is where the distance between the spheres and the pivot, is insufficient to describe the radius of curvature of the field(+some gravity stuff), and "falls" toward parallel to the magnet, but is stopped by the table. -Now in theory a homogenous disc, in a perfectly symmetric uniform field, could be balanced flat centre. But just as balancing a pencil on the tip, any perturbation would send the disk to one of the other states. -Reluctance is not really necessary for the description, as the same would happen if the reluctance for the ferromagnets matched the medium(ex. air).
Your assumption is correct 👍 we learned that in electronics education master class, while studying how conductors interfere with each other through field lines or how to construct electric motors
Its a good thing the washer didnt stick, you may never have gotten if off. I put a 1943 us penny (zinc coated steel) on a much smaller magnet and it was extremely difficult to remove
It's because the cast iron discs are concentrating the field lines of the magnet - there's only one polarity of field lines running below the magnet, so when you try to put the weight flat, the field lines coming out of the edges of the disc are the same polarity as the field lines coming from the bottom of the magnet. The same polarities repel eachother. This is why when you have 2 weights hanging by their edges, the bottom edges of the weights repel away from eachother. Same principal as a gold leaf electrometer - if there's charge there, it repels the same charge on the other leaf. The weight wants to migrate to the edge of the magnet so that the field lines coming out of the edges can wrap around the edge of the large disc magnet to the other side / other polarity
In air and with the ferrofluid the particles that are affected by the force are disconnected from each other and can move independently. In the barbell weight disparate particles are mechanically linked and so the relative strength of the magnetic field / Force are compelled to fight against each other by the linkage.
The flux lines are more concentrated at the edges so the plate will want to go to the edge so as to resolve (complete the magnetic circuit) more magnetic field lines than would be resolved at areas more towards the center, where the concentration or closeness of flux lines thin out slightly in comparison to those packed curved ones at the edge. Also if the plate were at the middle, there would be a bit of repulsion as the conducted directional flux would be projected out in slightly opposing angles to the approaching field lines of the opposite edge, especially in comparison to the plate being oriented at the edge.
Without watching the video, I am tempted to say that the shape of the weight essentially makes it have a strong anisotropy (shape anisotropy) when magntetized: so basically in this geometry it is hard to magnetize a disk along the out-of-plane direction because of the great number of surface "magnetic charges" that it would induce is a less stable state than magnetization in the plane, hence the way the weight hangs from the magnet.
Check out 'demagnetizing field'. Objects elongated in some direction tends to magnetize in this direction. Specifically, sum of demagnetizing coefficients N in X, Y and Z is 1, and N is approximately 0 in a very long direction (i.e. proportionally evidently the longest). Demagnetizing field, opposite to magnetization, equals NxM (for N=1 magnetization and demagnetization are equal). So for needle 'standing in Z' we have from symmetry N=0 for Z and 0.5 in X and Y - no problem with Z, max 0.5 out of what could be expected in X or Y. For plate 'lying in XY' we have N=1 for Z and 0 for X and Y, so no problem with magnetizing along plane, and almost no net magnetization along Z. Plates do not magnetize perpendicular to the surface. Screwdrivers magnetize only along main axis. This is also called shape anisotropy.
Easy answer: Same reason that iron filings make the patterns they do, but with slightly different consequences because of the shape and relative size equity between the magnetic field and the weight. The weight will naturally align itself with the magnetic field lines. Since the weight is a disk, it just makes it orient itself so these field lines travel perpendicularly through it's circular cross section. That simple. More mathy answer. The stable configurations represent orientations that maximize the Magnetic Flux through the weight, while the nearby unstable configuration represents a local minimum.
Ferromagnetic materials aren't "attracted" to magnets. They try to minimize the energy of the magnetic field passing through them. This functionally means that they follow (and try to contain) magnetic field lines. To be more precise, there are local minima in the configuration of whatever ferromagnetic materials you put near a magnet that require some amount of energy to reconfigure into a different (lower or higher) local minimum. You could do the same experiment with the weights on top of the magnet instead of under it but it would be much less stable with gravity working with the energy needed to reconfigure the weights instead of against it as it does with the weights hanging. How big a relative energy barrier there is depends a lot on the sheer mass of the chunk of iron you're putting on the magnet. The bigger the chunk of iron, the more magnetic field the iron can contain and the more (and deeper) the local minima of configuration energy. More simply: the larger the piece of iron, the more it can affect the shape of the surrounding magnetic field. I have a bunch of these very large neodymium magnets too and its easy to balance a pin or a razor blade or a screwdriver or knife point (or edge) towards the magnet with the object pointing up instead of hanging down.
My guess was, to put it simply, that opposite pole has to go somewhere when it came out the other end it's like what you explained with the repulsion keeping it from snapping onto it flat. Something like that. In any case it's always fun to watch a grown man still playing with magnets on a table haha
Try this with other elongated objects, like bolts, nails and screws. Maybe even try small metal bars. I wonder if the shape has something to do with it too, as most of the shapes you used had holes in them.
I really love when reality trumps common sense. At the beginning, I considered the dangers being raised to be very, very plausible. As you began to test them out, I was cringing inside, waiting for a strong reaction leading to disaster. What a cool video. Thanks so much!
I'm right there with you, I absolutely would be afraid to replicate this in person, even after seeing this video, eventhough I know better now.
B75; You are going to get in the center of the magnet.
Magnet; na, I don’t feel like it.
B75; I’m telling you, get there, now.
Magnet; I told you that I don’t want to.
B75; I don’t care what you want, right now. Go!
Magnet; make me.
B75; goooo
Magnet; clump
B75; come on back, let’s try it again.
Magnet; no, you can’t make me.
B75; come on, I’m tired of this. Let’s go.
Magnet; nnnoooo
B75; oooooooooooooooooo, that’s it don’t make me come back here with my stick. I will do it.
Magnet; mmmhh
B75; you have till the count of three. One, two,
Magnet; you will not make me move.
B75; come on, I got you. Come on.
B75’s back; this is tough. I don’t think it wants to come. Let’s give it a minute.
B75; no, I aallllmmmooosst have it. Come on legs. Put some work in.
Magnet; nnnnnooooon nnnooooonnnnooo
B75; ooooffff, I got it.
In these uncertain times, we need magnets more than ever. Large, powerful magnets, strong enough to guide us all.
Strong enough to align us all*
Fuckin magnets, how do they think?
Let your heart be your compass and knowledge be your candle. We won't get lost, love always wins. It might take lifetimes but it will win. One love, one family, one planet and only one you!
@E Van basically derranged pedophiles larping as commies
You only want a powerful magnet if it works with you. Remember it can also work against you.
5:30 there are safe shoes without steel. For various reasons, steel is now being replaced with other material.
The root issue is that steel is a shape memory material, and we now prefer that, once the deformation point is reached, material do not bend and punch the foot with permanent memorized pinched, but we prefer the materials to just break. Broken shoes are easier to extract. Pinched shoes are very difficult to remove at hospital, and once you know the energy involved passed any reasonable value, doctors prefer removing parts of shoes rather than having to grind steel literally glued to skin.
I don't know if materials are derived from plastic, glass, or carbone.
that and steel is expensive, random other materials are cheaper to produce so therefore bigger profits for the companies. Steel toes are superior in maximum performance but honestly if you're dropping nukes on your toes, you're doing something wrong.
Carbon Fiber, Fiberglass, and various polymers are pretty common. i think the CF and FG would be the best options since you can actually wrap them into the sole a bit to create a sort of toe box that's much more durable than just a toe lid or toe hat.
Actual steel toed boots are indeed getting more rare. Since they are frankly worse. (some insurance companies don't even regard steel toed boots as safe, and won't cover medical costs if such were used.)
Composite shoes with fiber glass, carbon fibers, or at times Kevlar are all more light weight, non magnetic, and cracks when overburdened instead of deforming. It is far easier for crushed toes to heal if not encased in a few mm of steel. And a lot of composite shoes are even stronger than steel ones, especially as far as weight is concerned. Composite shoes are though typically more expensive than steel ones, since making composites is more labor intensive then forming a piece of steel. (and steel is also cheaper than composites from a raw materials standpoint)
There is also plastic reinforced shoes, these are also much cheaper than steel, however less strong. But for a lot of lighter applications these are strong enough, while having the advantage of not encasing toes in hard to remove material.
@@dimitar4y "steel toes are superior in maximum performance" based on what? Your personal preference?
@@GameTimeWhy ... based on basic materials science? you fucking spergerstein? If carbon or plastic was better than steel, they would use those to make buildings, not steel beams. The two problems of steel toes is weight and irremovability once it *does* get crushed. But it's yield strength is the highest of all other offered materials.
3:40 you can see a gap between the plates when they're swinging, incredible
i think it's an optical illusion.
@@CM-xr9oq how?
@@awesomeavis7861 Because both are round, there's literally a point contact and it's hard to see in motion. But they're definitely connected at all times.
@@Hasan... if there was a point of contact you’d see it like you normally can when it’s not moving
I think we would either need the raw uncompressed footage or a slow motion camera to confirm this, the problem is that if the plates would seperate, the Magnetic force would decrease by the square of the distance, and the centrifugal force would increase as they sepperated, and because they are not connected and no change of medium there should only be a decrease in magnetism as the magnets begin to seperate.
After reviewing it in this fasion, I too believe its an illusion created by video compression and or the camera itself. I do not think they ever sepperated, and if they did, it would be Very brief and as a result of vibration, not centrifugal forces, soemthing that only a slow motion camera could catch it.
"Remember to like, *and maybe even subscribe* "
That's some good ol' fashioned humbleness right there. I respect youtubers who don't throw the request in your face, or try to guilt trip you, ect.
Your content is very reliably good, so a sub is a no-brainer. Keep up the good work!
Yeah, you came up with the same explanation I did, essentially. You put a ferromagnetic material up against a magnet, it becomes a magnet itself. Which means for long objects, the far end is the same pole as the face of the magnet and they'll repel each other. This is why paperclips stand up.
For the lying flat scenario, you'd have to absolutely perfectly center the weight under the magnet and have it be perfectly parallel to the magnet as you bring them together. Any variance at all would cause it to polarize the closer side as opposite to the face of the magnet and the far side the same, force it it upright.
yes, the whole explanation rests on the poles attracting and repelling each other.
That's what I was thinking, too; but in a much simpler way. Yours is better thought out.
Yeah your explanation sounds correct, it's exactly what I was thinking when I saw the weight flip up and the two bottoms instantly repelled one another.
You just explained it by yourself:
Ferromagnetic objects try to align alongside magnetic field lines, which are vertical at the magnet center and horizontal at the edges.
Yep, exactly what i came for in the comment section :)
We should call this the brainiac theory! Ba dum tis
this would look really strange if people didn't know there was a magnet up on the table.
Or what magnets are
A hidden magnet channel, where unwitting strangers suddenly do battle with an invisible force. :-D
I think it looks strange enough even when you know there's a magnet.
And also I think it would be impossible to see without realising that there must be a magnet.
Brilliant! 😀 the clip of you doing the reverse weightlifting gave me great laugh. Stay safe and remember to degauss your weights before your next session 👍😀
10:36 now I'm curious: What does the FEM simulation look like when the weight is flat on the magnet and at an offset like shown at 7:43?
I like your magic words funny man
Damn. That's a nice question. Got me thinking... This is my take on it 🤔
I'd think it would still be the same. Though the fieldlines at the side are more going sideways and to that are more dense.
So adding a flat metal on the left side, many field lines pass through the left side of the metal in an almost parallel manner to the metal. Only few field lines are in the opposing direction on the right side of the metal.
So I'd say, the left sides attraction overpowers the repulsion of the right side.
Maybe the weight ‘conducts’/refracts/redirects’ the field lines convergence points. If each line has areas of N and S along it…then perhaps it could be that as these parallel lines approach so too does the attraction between them.
The way i interpret the software makes me "see" why that works but would still be weaker, but actually seeing it in the software would be aweaome
The software FEMM is freeware.
Your videos are some kinf of hypnotic, really! I can't wait the next one, every time.
I am taking a Physics class right now and the one thing that my physics professor would say is that there are no monopoles. When you magnetize an object (or creating a temporary magnet by introducing the iron to a magnetic field), you are creating an object with both a South and North Pole. The paper clip and the weight do not want to lie center of the magnet because their temporary poles are repelling them against the magnetic poles. This causes them to align themselves with the magnetic field in the direction with the largest decrease in magnetic strength, in this case vertically.
At the edge of the magnet, there is a large decrease in magnetic strength between the center and outside where that magnetic field curves from parallel to the edge to the center of the magnet. The induced magnet in the iron makes it really easy to align the metal to the edge of the field.
Omg I never knew how much I needed this ESA merchandise in my life
I get in enough trouble with small Neodymium magnets.
You can also see this in the videos of MRI magnets that are being decommissioned. The various metal objects released near the magnet stick out instead of being pulled flat against the magnet. Search _magnet quench_ for hours of entertainment.
they should put a superconductor in the room with those magnets, please get somebody to try that. xD
I love the one where you can see a liquid running off the helium exaust tube, and it's actually ambient air condensing and raining into the room!
@Seldoon Nemar dangerous, too. Mostly LN²
@@hughbrackett343 I was less worried about he LN2 and more worried about the straight O2 mixed in there as if you were doing a quench in a true emergency, I think liquid air is a flamibiblity hazard. I'd hate to hear about a piece of electronics getting sucked onto a patient so they quench and a fire breaks out in the room... that's nightmare fuel
@Seldoon Nemar true, I forgot the LOx is a huge fire hazard.
Your explanation makes perfect sense to me and aligns with what I have seen here in my own much smaller scale experiments.
It's hilarious seeing you fight that magnet. Great video.
I recognized this phenomena over a decade ago, using things like paper clips, nails, and other objects. Your graphic explanation is exactly how I rectified it in my mind back then, so I believe you're 100% correct in your analysis. Now, where things would go terribly wrong, and you would lose digits or eyes, is if you tried putting another similar magnet under the table! Then things would happen exactly as others feared, and it would snap flat and center, or if two, they would snap together in either direction dependent upon certain variables. Needless to say, it would be foolish to even try! Absolutely love your videos...
Edit: btw, I'm guessing you can take those washers or paper clips, and easily lay them flat along the edge of the magnet face...
the force of the snap would definitely break the table, too. and probably the moving magnet.
Lovely, These videos are always so entertaining and I can watch hours of this stuff , in fact I liked it so much I have some strong magnets of my own! (weak to yours lol) and your explanation seems correct one of my favorite videos.
Glad you like my videos! All neodymium magnets are strong. No need to go as big as in this video ;) Much more videos to come.
I would be interested in seeing you test the snap force, using a hand/finger made out of ballistic gel & bone. A good visual of the possible danger to hands/fingers.
Hot dogs! Haha
Electromagnetism never loses it's magical appeal to me.
It is so 'other-worldly'
One of the great wonders of nature.
Well done Michael Faraday!
This is a brilliant demonstration of induced magnetic fields.
The explanation is very counterintuitive to what most people understand about how magnets work. A number one rule in physics is that magnetic fields can't do work. On its face, this seems to fly against everything we know from practical experience. However, what generates the forces that we normally experience when we play with magnets is actually the magnetic field gradient. In this case, your supposition is correct. When the dumbbells are oriented edge on the gradient is very strong, which induces a very strong corresponding magnetic field in the iron. This feedback pulls additional field lines in until it reaches equilibrium. When it's parallel to the surface though the magnetic field gradient is very weak, and therefore induces a very weak field in the iron.
New upload from Brainiac75 on this Beautiful Sunday morning!
Thanks, Maximus :) Beautiful, but cold evening here in Denmark ;)
I really like your work. I've always been a big fan of magnets and magnetism.
I experienced this phenomena about 30 years ago. I played around with my keys outside a NMR cryogenic magnet and discovered that the keys were pulled towards the magnet along the magnetic field lines, but following the lines around the keys now pointed away from the magnet while pushing against my finger... I kept a very tight grip of the ring holding my keys. :-)
To explain any physical system, just look at the energy in the system. For this case, when the object aligns along the magnetic lines the energy is locally minimized. If you want to turn the weight there is a energy penalty to overcome. If the system is in a stable state you have to add energy (force x distance, poking with a stick) until you reach a maxima and the system can drop down into the next minima of the system.
In my example of the keys and in your video it means that the object is in a local minima and can't turn as it requires more energy than the system possess. Adding energy in the form of violently shaking things could bring a system from a local minima into a deeper global minima. The other way around is harder.
I've been too long-winded, so I just say, Nice video! :-)
Gonna say getting under a table extension, bracing your foot on it, and pulling against a heavy magnet on top is a fair bit more dangerous.
This is because of the Demagnetization Field. This term and its explanation can be found in litterature and in most books on magnets, like Blundell's book on Magnetism. In this example, when a magnet is flat in one dimension, the H field between the two imagined "Magnetic charges" on the top and bottom layers cancels out the Magnetization field, M - because they go in opposite directions. For long objects, the "magnetic charges" are far away from each other, thus the H field inside the magnet is small, and a large Magnetization can occur inside, which was what your simulations showed.
When simulating and calculating this effect, you will need to specify the Demagnetization Tensor, which gives tells how much the magnet Demagnetizes itself in different directions - the shorter the magnet, the larger the Demagnetizing effect.
another video so soon! such a pleasant surprise!
February is short, but I managed to make a long video ;) Much more to come. And thanks for the early watch, sulfie!
The easiest way to analyze it is probably in the context of equivalent magnetic circuits. I don't have too much experience with them, but I believe what's happening is that the weight is moving into the position which minimizes the magnetic reluctance. There's a lot of good info online about magnetic circuits.
It's so counter-intuitive because just looking at it, we assume it to behave like gravity, which (I believe) behaves in straight lines. But magnetic fields aren't straight lines, and the poles don't act like mass.
whats interesting to note is the weight reduction while under the effects of magnets while swinging. if polished surface might swing for every. great content sir
I love when an new video comes out!
Thanks!
hi good to see you back
Never really been gone ;) Check my channel for the monthly uploads.
Great video as always.
Like others in the comments, I would enjoy seeing that magnetic field program depicting a flat weight offset from the center of the big magnet, for comparison, if that is possible.
I'm curious if different shaped magnets would change things, like more of cylinder shaped magnet or a cube shaped one
03:40 when the weights started swinging, there are moments where they aren't even touching, but still follow the magnetic force! :D
Always scary when he pulls his magnets out! I’m surprised they haven’t eaten your fingers. Please be safe love your video they are very informative
Your theory makes a lot of sense to me.
I have a theoretical experiment that could be performed in order to test the theory.
Place the magnet so that it is at a 90° angle from your usual positioning on top of the table. Slowly bring the barbell weight towards the bottom of the table first in the usual perpendicular to the ground and then parallel to the ground. And we'll see which orientation has the stronger magnetic attraction.
It has to do with the shape of the magnetic field. It's stronger near the edges and in the center.
Depending on polarity, the field will flow up from near the edge on the face of the magnet, and flow towards the middle, or the other way around. This means that it wants to "short" the magnetic field through the metal you use. This poses a few different issues:
1: the material is saturated by magnetism, and is partially attracted to the magnet, but also repelled, much like the experiment of having 2 metal strips hanging, charged at the same high potential will repel.
2: for the weights with a hole in the middle, you'll likely still have the same issue as above, but it's likely made worse by the fact that you have a hole in the middle, where the opposite polarity to the edge is.
If you had a thick cylinder without a hole, that has enough mass and capacity to not be saturated by the magnet, it would likely happily stay in the middle. If it does not have the magnetic capacity, a chunk of metal that big, might just flip the magnet in stead.
Best quote I have heard in a while. "I'm not a fan of the implied forced appreciation".
Within the magnetic field of the neodymium magnet, the weight becomes its own magnet. I my opinion, it's a question of geometry. The same poles on a magnet want to be hella far from each other, so any object placed towards them should line up in a stable and long orientation.
When i think about it, all i could think of is how the magnetic field spins around its edge and go through the center densely and straight down, therefore grabbing the also-vertical magnetized object in a better position. It seems i was kinda right, but thanks alot for the color/visualization of it! 👍
I like your other videos where you respectfully warn viewers of the various potential hazards associated with the content, but never assume that they are not capable of coping with them on their own. I click away from other videos when they assume somehow none of us are as capable.
I am amazed at how little we understand these things. We can describe them so accurately, but no one can explain a "mechanism" of cause. That kills me, and most don't even see the difference between "what" it does and "why" it does it. And then, magnetic lines do not exist, but most people think they do. The lines come from our attempt to describe and visualize, but the field itself is smooth and homogeneous. The spikes in the fluid come from how mass channels the field around other mass, not from the field itself.
The way I look at it is that the permanent magnet induces a dipole EM field into the iron weights, and the most stable self-organizing configuration is where the poles of that induced field have the maximum possible separation. Pushing the weight flat forces a metastable state around a local potential mimima and the quick flops represent the local maxima where the configuration slips from one energy well to another.
It's a function of the Surface area that interrupts the magnetic field, and total distance the field has to travel through the material, and the material's magnetic permeability. Think of how magnetic chucks for CNC machines work.
I don't think behaviour of magnetic chunks of cnc machine is common knowledge...
@@NoNameAtAll2 that's why i mentioned it so people can look into it and learn more about it, as it gives a lot of intuitive knowledge about magnetism.
@@NoNameAtAll2 well it should be lol
#ripmanufacturing
@@dimitar4y shout out to to HAAS youtube channel! Great vids on chucks and EVERYthing else.
Thanks! Gave me an idea for a magnetic catapult!
In any arbitrary configuration of magnets and ferromagnetic objects, the force always is in the direction that increases the total magnetic flux. The flat disk of iron on a pole increases the total flux just a bit, but any tilt increases it even more. So the flat approach is not stable. If the disk were perfectly constrained to move only along the axis of the magnet, it would be weakly attracted. But the slightest tilt would produce force that increases the tilt.
During the video, my speculation was also that it had to be related to the direction of magnetic field lines, where the illustration with a paper clip is more illustrative with the much larger size difference, that it is actively pushed up. Appears that the magnet does not like the lines "trapped" in the metal object being bent too much.
12:40 I can smell that "fresh book" smell, right through the screen.
I've always been curious of this behavior... it makes sense after a reminder of the poles and fields.
I was about to write something "because in a flat position the field would become an unstable mess", but you've demonstrated it in a sim. The magnetic lines that would form in a pancake will not form a good magnetic dipole, instead having poles scattered as rings god-knows-how. There is a big difference between being a magnet, which is best flat, and being magnetized.
The reason there is no scientific papers on that problem is probably because it's quite straightforward.
It's enough to consider 2 things:
1) Magnetic field can represent potential field by sort-of-inversing curl.
2) Everything in mechanics wants to achieve the maximum drop in potential energy possible, given the initial conditions (see Euler-Lagrange equation). Or everything follows the path of the most drop in potential.
From those two, an axis aligned flat object on a magnet would experience the least possible potential (field) drop. There are neighboring positions with higher drop and the object will try to jump to them. This is as plain as putting two spheres one on top of another: the position is unstable and the top one will roll down.
Lying flat off-axis over the edge of the magnet is also stable, although less stable. That creates a crisscross pattern for the poles in the magnetized object where the hanging part of the object is attracted to the side of the magnet, because it is polarized in reverse and wants to attach itself to the side.
Fun fact- this is why stacking thin sheets is used for motor rotors. the magnetic lines build up in the plates individually to make strong layers.
That magnet seems seriously strong ... I wish I could get one of those to play with in person.
i've always known objects will be forced into alignment with the magnetic field's directions, but i've never really thought of it this way. its the same reason that when you sprinkle iron dust on a magnet, it doesn't all clump tightly to the magnet and instead forms peaks along the field's vectors. there is probably a formula correlating magnetic flux vs moment of inertia in regards to the shape of things and their mass being affected different ways.
Maybe you could make video where you heat the weight and let it cool while still in the magnetic field? How strong a magnet can you make with your super magnet ?
11:59 I don't know if it's the same thing but the spike form in ferrofluid is due to an effect called Rosensweig or normal-field instability.
6:46 That was scary, you could see the magnet move. That wasn’t so safe 😀😬
Magnetic shape anisotropy will always prefer to magnetize the material in the longest direction possible. There will be less domains compared to other directors and will always be the case unless you're dealing with single crystal materials
Great Video Earthling , How About Using A Ball Bearing In A Plastic Tube That Switches Back And Forth As A Switch ?
Bless Up
Wow, I wasn't expecting you to be able to move them that far. Those magnets really are scary stong though.
Your explanation sounds good to me
5:25 That gives me some bad/silly ideas, like putting magnets in the attic so you can walk on the ceiling.
8:25 it has very high "flux density" if you sprinkle more paper clip on top (or better still, tilt the magnet on it side) with a piece of paper, it no different if you sprinkle iron powder onto a paper with a smaller magnet underneath, showing the "pole orientation pattern".
I wrote a 10 page assignement on magnets a while ago. Your explanation as far as i know is correct. Though the resistance to flipping aweight is not only due to the repulsion but also because you move the weight through and out of the fieldlines. Though i'm not a 100% on that part.
I think it's that the weight becomes a magnet and it tries to keep the same pole away from the magnet.
I bet after this the weights are slightly magnetic from being in such a powerful magnetic field.
In fact used fitness weights are often spontaneously magnetized due to the Villari or inverse magnetostrictive effect, because they're banged around so much.
@@Muonium1 Got any keywords I could use to find information on this? I searched but couldn't find any good information
@@ldskjfhslkjdhflkjdhf The Action Lab did a video not long ago about tapping iron to make it magnetic. Check it out:
th-cam.com/video/oNjMLtHFxkU/w-d-xo.html - Can You Magnetize Iron Just By Tapping It?
It works when tapped by aligning magnetic domains in the metal to the earths, or other strong nearby fields.
@@ldskjfhslkjdhflkjdhf ya, ummm "Villari effect". haha. here, just let MacGyver teach you:
th-cam.com/video/QmEi-rWPnAc/w-d-xo.html
🤣🤣
@@Muonium1 yeah, I know about the Villari effect (plus it's mentioned in the comment I replied to), I'm talking about information on weights specifically being magnetized. I can't imagine the stresses on gym weights are distributed uniformly enough to cause them to become magnetic to any significant degree. Plus the weights are so big. I found the claim surprising and was hoping you had a source or something you were drawing from
i just BURST out in lauthter at 5:12 - no joke you're a creative t(h)inker :D and i havent even finished the video yet! this is why i love your channel!
I don't know much about permanent magnets other than the iron filings experiment I did in school (well also things like the curie point and stuff) though I was about to sketch out the exact same thing in your simulation.
It's easier to picture in my head but because the field lines extend out almost perpendicular to the magnet they'll 'interface' better with perpendicular objects.
Edit: You explained it better.
When the weights started swinging at around 3:41 it appears that the bottom one separates for a moment at every swing before been pulled back by the magnetic field. Was that so or was it just my impression?
iron is not only attracted to a magnet, but it also becomes a magnet itself. It couples to a nearby magnet and reshapes the field giving rise to another pseudo N & S pole.
I've been loosely trying to make formula for this.
One aspect of the geometry you didn't explore further was that all of the pieces you experimented with were toroidal (have a hole in the middle). That air gap may also play a role in the magnetic fields preferred pathway. It may be easier to center a solid disc vs a donut. I still believe the preferred orientation would be to hang but it may not snap off center as consistently like the barbell weight.
So, I'm at 1:00 even, and my guess is that it's the same thing keeping us from evolving wings, and from free energy. The universe seems to like the lowest possible energy state, and it seems like gravity pulling on the weights effectively cancels out the "desire" of any given weight to flip up, like a ball trying to roll uphill. Yes, there's plenty of force there, and yes it's a more stable position to get to flat with the magnet, but doing so requires overcoming gravity. Same goes for the other magnets, as they're held up from the conducted magnetic field through the weight above (kind of like a "lense" for the magnetic field, it's strongest on one pole where it's closest to the magnet, which means to me it's strongest on the other at the exact opposite point), kind of like how transformers have an iron core to increase efficiency. I'm not a physicist, mathematician, or anyone qualified to talk about any of this. Just my pre-video guess. Excited to see if any of this is brought up
What was interesting was how instantaneous the weights jumped into position to align themselves with the magnetic field, as if their mass was completely negligible. Did they even conform to the standard rules of inertia and F = ma? From the video you could estimate the force on the weight to make it jerk move that fast (and jerk to a stop).
nono..it appears right...it was more or less exactly what i thought would apply.
many thanks for your work.
the channel is truely, a great source of knowledge :3
stay safe :3
3:44 Are the weights actually separating here or is it just TH-cam compression?
Great video as always!
I'm curious to know whether the geometry of the Barbell weight plays an additional part to the story; in your simulation you've treated the weight as a solid mass where the north and south poles will be orientated at opposite ends, but in reality the barbell is a Torus, is it possible that the magnetic field is aligning with an opposite pole on the internal curve?
Thanks for showing all this neat stuff. Could you please do a video where you show the magnetic axial flux lines with ferrofluid, and then rotate the magnet around that axis? This would visualize the Faraday paradox, that still today isn't fully accepted or understood. A rotating stand with a monster magnet on top - a glas bowl of ferrofluid would do the trick? 😇
7:00 - as seen on tv advertisement when showing some one using the inferior version of a product to accomplish an every day task…
Individual magnetic field lines extend between north and south in concentric torus shape. Your iron is attracted srrongly to the flux in one magnetic field line at a time - linking/unllinking field lines has a canceling effect.
Consider a rod with two ferromagnetic spheres on each end and a pivot point between them.
-Introduce a magnetic field in the form of a dipole magnet.
-Influenced by this external field the spheres will find the internal field that minimises the torque about the pivot. If not for gravity the rod would be tangent to the external field.
-The other state, is when the magnetic restoring torque, is cancelled by the normal force of the table.
-The inflection point, is where the distance between the spheres and the pivot, is insufficient to describe the radius of curvature of the field(+some gravity stuff), and "falls" toward parallel to the magnet, but is stopped by the table.
-Now in theory a homogenous disc, in a perfectly symmetric uniform field, could be balanced flat centre. But just as balancing a pencil on the tip, any perturbation would send the disk to one of the other states.
-Reluctance is not really necessary for the description, as the same would happen if the reluctance for the ferromagnets matched the medium(ex. air).
Your assumption is correct 👍 we learned that in electronics education master class, while studying how conductors interfere with each other through field lines or how to construct electric motors
Its a good thing the washer didnt stick, you may never have gotten if off. I put a 1943 us penny (zinc coated steel) on a much smaller magnet and it was extremely difficult to remove
It's because the cast iron discs are concentrating the field lines of the magnet - there's only one polarity of field lines running below the magnet, so when you try to put the weight flat, the field lines coming out of the edges of the disc are the same polarity as the field lines coming from the bottom of the magnet. The same polarities repel eachother. This is why when you have 2 weights hanging by their edges, the bottom edges of the weights repel away from eachother. Same principal as a gold leaf electrometer - if there's charge there, it repels the same charge on the other leaf. The weight wants to migrate to the edge of the magnet so that the field lines coming out of the edges can wrap around the edge of the large disc magnet to the other side / other polarity
I'm waiting for the Brainiac75 video in 10 years where he's created magnetic monopoles in his kitchen through testing viewer suggestions.
In air and with the ferrofluid the particles that are affected by the force are disconnected from each other and can move independently. In the barbell weight disparate particles are mechanically linked and so the relative strength of the magnetic field / Force are compelled to fight against each other by the linkage.
It will be helpful to mark ends (sides) on your barbells, as if they are positive and negative, to helo us recognize when they do spin before flipping
The flux lines are more concentrated at the edges so the plate will want to go to the edge so as to resolve (complete the magnetic circuit) more magnetic field lines than would be resolved at areas more towards the center, where the concentration or closeness of flux lines thin out slightly in comparison to those packed curved ones at the edge. Also if the plate were at the middle, there would be a bit of repulsion as the conducted directional flux would be projected out in slightly opposing angles to the approaching field lines of the opposite edge, especially in comparison to the plate being oriented at the edge.
Without watching the video, I am tempted to say that the shape of the weight essentially makes it have a strong anisotropy (shape anisotropy) when magntetized: so basically in this geometry it is hard to magnetize a disk along the out-of-plane direction because of the great number of surface "magnetic charges" that it would induce is a less stable state than magnetization in the plane, hence the way the weight hangs from the magnet.
My intuition is linking this to the effects seen in superconductive levitation, for some reason.
Check out 'demagnetizing field'. Objects elongated in some direction tends to magnetize in this direction. Specifically, sum of demagnetizing coefficients N in X, Y and Z is 1, and N is approximately 0 in a very long direction (i.e. proportionally evidently the longest). Demagnetizing field, opposite to magnetization, equals NxM (for N=1 magnetization and demagnetization are equal). So for needle 'standing in Z' we have from symmetry N=0 for Z and 0.5 in X and Y - no problem with Z, max 0.5 out of what could be expected in X or Y. For plate 'lying in XY' we have N=1 for Z and 0 for X and Y, so no problem with magnetizing along plane, and almost no net magnetization along Z. Plates do not magnetize perpendicular to the surface. Screwdrivers magnetize only along main axis. This is also called shape anisotropy.
Your monster magnet attracted me to this channel 😂
You're smart👍
Easy answer: Same reason that iron filings make the patterns they do, but with slightly different consequences because of the shape and relative size equity between the magnetic field and the weight. The weight will naturally align itself with the magnetic field lines. Since the weight is a disk, it just makes it orient itself so these field lines travel perpendicularly through it's circular cross section. That simple.
More mathy answer. The stable configurations represent orientations that maximize the Magnetic Flux through the weight, while the nearby unstable configuration represents a local minimum.
Ferromagnetic materials aren't "attracted" to magnets. They try to minimize the energy of the magnetic field passing through them. This functionally means that they follow (and try to contain) magnetic field lines. To be more precise, there are local minima in the configuration of whatever ferromagnetic materials you put near a magnet that require some amount of energy to reconfigure into a different (lower or higher) local minimum.
You could do the same experiment with the weights on top of the magnet instead of under it but it would be much less stable with gravity working with the energy needed to reconfigure the weights instead of against it as it does with the weights hanging.
How big a relative energy barrier there is depends a lot on the sheer mass of the chunk of iron you're putting on the magnet. The bigger the chunk of iron, the more magnetic field the iron can contain and the more (and deeper) the local minima of configuration energy. More simply: the larger the piece of iron, the more it can affect the shape of the surrounding magnetic field.
I have a bunch of these very large neodymium magnets too and its easy to balance a pin or a razor blade or a screwdriver or knife point (or edge) towards the magnet with the object pointing up instead of hanging down.
My guess was, to put it simply, that opposite pole has to go somewhere when it came out the other end it's like what you explained with the repulsion keeping it from snapping onto it flat. Something like that.
In any case it's always fun to watch a grown man still playing with magnets on a table haha
I'm curious what effect the hole in the weights has, if any
Try this with other elongated objects, like bolts, nails and screws. Maybe even try small metal bars. I wonder if the shape has something to do with it too, as most of the shapes you used had holes in them.