Hi! A couple of times I have shown how my monster
magnets easily hold barbell weights over quite a distance. However, I have received comments on how lucky I was that the weights did not flip up to
be as close as possible to the magnet. Or sandwich together. Possibly pinching my fingers into a blend
of shattered bones and minced meat. Fair point. In this video, I will test how likely it is to happen. Have I been on the edge of a disaster? Don't play with big neodymium magnets. Let me do the crazy experiments, so you dont have to. All right. Let's poke the sleeping bear. Will the weight slam up against the
magnet at even the smallest angle away from being perpendicular
to the magnet's pole surface? No, let me adjust the direction. Naah, the weight is finally lifted
but caught on a wooden crossbar. And not eager to go all the way at high force. It is also easy to pull back in starting position. Let me push it the other way and avoid the crossbar. Yeah OK. Sounds like it would have been
unpleasant to have fingers caught in the snap. But notice the angle I had to lift
the weight to before it snapped. I would never have lifted it
that high with fingers in between. And it is not that keen on staying flat on the magnet. I can relatively easily pull it back. Now, let's up the ante. With two weights under the magnet, there are more
failure options and simply more force involved. Since I will enter uncharted, terrifying territory here
I decided to put some protection around the magnet. In case one of the weights go haywire, fly around
the table edge and hit the magnet directly this box may prevent chipping
a magnet worth over 1000 $/€. Or maybe not... After putting on a face shield - and
adjusting the angle - I am sort of ready to go. This feels so wrong - second attempt. Wow, the weights did not create a pinch risk in this case
since they did not stick flat to the magnet. In stead I have a hard-hitting 5 kg swinging pendulum. Fascinating and frightening at the same time. What if I attempt to sandwich the two weights together
under the center of the magnet? Again, I had to go to a crazy
angle before something happened. For me it seems unlikely anyone
would risk going this far up by hand. But once I pushed it too far
a lot happened. Very fast. Remember these are made of solid cast iron. It takes some force to accelerate them this fast. All in all, it seems like I have to go to surprising
angles before an accidental pinch could occur. Still, do not ever try this yourself - results may vary. Let me clean up this mess
and switch to an even wider magnet. Easier said than done. Feels like the table extender
will give up before the magnet. Time for some upside down weight lifting I guess. Yes, I do have a quirky mind but sometimes
it helps in untried situations like this one. And yep, my safety slippers have been
upgraded to steel-capped shoes. I wonder if we will see a different
reaction with this very wide magnet. Can I get the weights to stay flat
on the center of this one? Not a major difference. Maybe more energetic when allowed
to go the edge of the magnet's pole. But shouldn't the weight be able
to lie flat under the magnet's center? By hand it seems impossible. The weight wants to tilt or go to the edge of the magnet. I will now attempt to force it to stay
flat under the center using a handle. Hard to describe how unreal this feels
but it is like the weight is telling me: 'I prefer to stand like this. Let's not fight over it.' One final attempt - it must be possible. Nope - the weight will only rest parallel near the edge
of the magnet or perpendicularly under the center. What is going on? Here are some other examples
with more manageable items. It seems counter-intuitive. Why will a magnetic object not
stay flat on a large magnet's pole center? The magnetic field is after all stronger
the closer you are to the surface. It seems to be an effect in elongated objects. This nut is less elongated and
will stay flat with some persuasion. After a short message, I will give
my guess on what is happening. A big, BIG thanks to all my patrons. Thank you so much for helping out! It's really appreciated and
important for a niche channel with monthly quality uploads like mine. For just a dollar a month
you can help me out too and get full access to all my posts on patreon.com Link to my Patreon page in the desciption. Thank you! I have not found any papers
explaining this phenomenon so I had to come up with my own guess. To make it a qualified one, I used the free program
FEMM to simulate two scenarios with the barbell weight. One with it hanging down from the center and one where I somehow
managed to lay it flat on the center. And for both magnet sizes, there is a striking
difference in how the barbell weight is magnetized. Notice the colors. Magenta marks the strongest magnetic field
followed by red, orange, yellow etc. The weight is significantly stronger
magnetized in the upright position. This appears to be the explanation. When upright on the center the weight is aligned with the almost straight and parallel
magnetic field lines coming from the magnet. And the magnetic field lines even cluster together in the weight
since it is better at conducting a magnetic field than air. In technical terms, the ferromagnetic weight
has higher magnetic permeability than air. With a lot of parallel, long field
lines going all the way through the induced magnetism in the weight is very strong. All the magnetic domains in the weight are more or less
aligned to form a classic dipole bar magnet. In the other - almost impossible scenario - the magnetic domains inside the weight are not teaming
up to form a magnetic field with a uniform direction. The field lines are curving away from each other. Many field lines are leaking out
at both the bottom and the two sides. The weight is weakly magnetized
without two clearly separated poles. It is a mess. No wonder the magnetic domains inside
the weight prefer the weight to be upright. Working in harmony with the monster magnet. Like the spikes rising up in ferrofluid over a magnet's center. The strong dipole magnetization of the weight also
explains, why it is reluctant to fly up against the magnet. The bottom part has the same
polarity as the big magnet pole above. Equal poles repel each other, so once magnetized the bottom of the weight wants to be
as far away from the magnet as possible. And two weights will not sandwich together under the magnet
since they will have equal poles next to each other. Creating a strong repulsion visible in the sandwich tests. I believe the magnetic geometry and equal pole repulsion
make this setup safer than it may appear at first glance. Based on both hands-on experience and simulations. Still, do not ever try this yourself - results may vary. And I could be wrong. Comment if you have another explanation or if you
know of a scientific paper examining this phenomenon. Speaking of attraction and repulsion
you may have seen my posts on Valentine's Day. I am not a fan of the implied forced appreciation. If it doesn't come naturally
I am repulsed by it like a diamagnet. Apparently, the European Space Agency
- ESA - sometimes feels the same and put some refreshing humor into
some limited-edition merchandise. They sent me a few free samples from their Space Shop. I must admit I didn't know they have a webshop
and was surprised by how much they have in store. If you haven't seen it either, I have put a link
to the ESA Space Shop in the description. Hope you enjoyed this video
as much as I enjoyed making it. Remember to click like
if you think I deserve it. And maybe even subscribe
for more scientific discoveries. Have you seen my video, where I examine
a magnetizer/demagnetizer tool? Thanks for watching.
Bye for now.
