Magnetic Hysteresis or I KNOW WHAT YOUR MAGNET DID LAST SUMMER | Doc Physics

[@nathan6798]

You are seriously a life saver! So refreshing to have someone explain colloquialy... This is how you explain a concept well and quickly.. I dont understand people who try and overcomplicate concepts for nothing

[@power-max]

YES, Finally a worthwhile video explaining concepts like thin an *engaging* way rather than some old fart in the distance on a green chalkboard moaning on hour an hour and a half, You have rightly earned my subscribe!

[@DocSchuster]

Power Max Thanks, yo. We'll all be old farts someday, though. We'll have to be careful not to bore the kids then!

[@power-max]

Doc Schuster Haha I know, I always try to teach and explain difficult concepts using analogies and examples exactly like you, though not formally since I have not yet earned any degrees in engineering or physics, though I love to learn stuff, especially when I want to select the proper transformer (like a big chunky 60Hz iron core vs tiny ferrite or air-core RF Xformer) for a given project. I actually still haven't finished watched the video, I am at 11:30 and was 'eureka' for me since it not only made the 'saturation' concept clear to me, but also the fact that magnetism doesn't just go away so easily by removing the external field, that it learns around, just like what I discovered when I was pulsing current through a wire and discovered that a nail became permanently magnetized in my workshop/lab.

[@DocSchuster]

Power Max Pleased to meet you! You seem very cool!

[@frodobaggins6450]

You just made me think of my teacher standing up, fumbling through his notes an reading them to himself.

[@ahorsewithnoname935]

I don't know how I ended up here, but that was the most educational 20min of my life. I love when someone is able to explain and demonstrate a topic so well that you're left thinking at the end "yeah, I already knew all of those concepts." Yet collectively you have never put them all together to make a cohesive thought or conclusion. Thank you for explaining.

[@o0o0styx]

i picture this guy rolling into class on a skateboard wearing a backwards cap.

[@SHONSL]

LOL I can see that.

[@abhishekshankar1136]

you know i picture this guy as a cool stud in shorts with his cap backwards and marker in one hand proving E=mc2 like a boss

[@dipankarpurecha5564]

Yeah, with gold chains and bracelets

[@Ben10_ka_bhai]

Bruh ! 😂

[@alperentopay1164]

I wish there was more of you at our college of engineering. Would make life so much easier.

[@xavierturano548]

AT THE END OF THE VIDEO I REALISED I DIDNT HAVE TO TAKE ANY NOTES BECAUSE YOU TAUGHT SOOOOOOOOOOO WELL ALL THE ANALOGIES AND THE ENERGY YOU HAD WAS ENOUGH TO BURN WHAT YOU SAID INTO MY HEAD. A SOLID 10/10 WELL DONE

[@Anya-ty6oh]

This is like the best explanation of hysteresis. If teachers taught physics this way, the world would have been a better place.

[@Roberto-do9ny]

You know how to teach unlike my lecturer!! thank you so much, and the humour helps remember the concept even better :)

[@victordolman2646]

I always find hysteresis scary. It reminds me of how lucky we have been so far that it is not real. Actual, fundamental hysteresis would be a devastating blow to physics. Not fatal maybe, but an enormous setback. Sharing my fear makes me a little less afraid, so that is what I'll do. A basic feature of fundamental theories, classical Newtonian or quantum mechanical, is that it is possible in principle to specify an initial state of a system, and then the theory (again in principle) tells us everything about the future of that system. This also applies to spin, so one might wonder how ferromagnetic hysteresis is possible at all. The fundamental equations (say a many particle Schrödinger equation with magnetic interaction terms in the Hamiltonian) simply allow any initial state to evolve uniquely in time. So there should not be any hysteresis at all. The answer is basically this video. The story you tell shows explicitly how hysteresis does NOT occur, but is only apparent. If we think that the state of a piece of iron is adequately specified by giving its (unperturbed) magnetic field, we are mistaken. The configuration of the domains and their boundaries is also an essential part of the state of the system. If we choose to ignore them, we will not have a unique time evolution. If we take them into consideration, as you do in the video, the whole system becomes an ordinary case of a state whose future depends on the current state, but not on its past. You go through it, step by step. So thank you for showing the absence of hysteresis :-) In a few minutes I'll go to bed, switch off the lights and try to sleep, if I can. But I'm not sure I can. Suppose there would actually be hysteresis that no one can explain away by including more properties into the state, as you did. Then the future of a system would actually, really, unavoidably, depend on its (entire) past. Quantum mechanics would be wrong, and so would Newton. The whole mechanism of partial differential equations would not be relevant to physics. We would, in short, have almost nothing in the way of physical theory. When I imagine this, I cannot help but feel horror. Thank you for listening to my fear. It really helps. Goodnight. :-)

[@tyyamnitz3531]

i'm confused.. He just demonstrated hysteresis and newtonian physics are still intact. What is your fear?

[@prikarsartam]

You're simply wrong. Mind you that a little learning is a very dangerous thing.

[@anamendoza6741]

First year of chemical engineering at taipei, videos like these are my saving grace. God bless you😂

[@shikamaruX11]

this was beautifully and hilariously explained, thank you

[@ziyodbekyunusov9586]

"Lets name this sucker", hahah Great explanation, Thanx.

[@abbas_oso]

this dude is insane why don't we have more educational content like this these days

[@redpowerranger5935]

Very good video! Thank you for that! To bring a ferromagnet back to its (0,0) point on your B residual vs B ext graph, you can heat it to its Curie temperature rather than hitting it!

[@DocSchuster]

Red Power Ranger An excellent point!

[@Shahriar019]

My god! All these years I've been hearing "Physics is Fun!" Now I definitely know why!!! Thank you Doc!

[@Eddierocket2010]

you are the best an funniest teacher. thanks for being you

[@pisquare5107]

am in college now...and i came upon this while seaching for lab exp.. reminded me of my high school days (yes i highly depended on Doc Schuster's lectures during my school days) .. and glad to come across it again :)

[@talhaseemab8064]

your enthusiasm is appreciable

[@kalmahnalyd4615]

Why don't I have a teacher like you in my school? You're awesome man!

[@harshuttarwar1027]

holy.. only if I had a teacher as cool as you.. never understood a concept better.. beautiful way of teaching man.. you earned a subscriber!!

[@Ben10_ka_bhai]

You unsubscribe 😂

[@tiana5033]

This is absolutely delightful and brilliant. I'm cracking up and learning so much :D

[@levidr7]

I was looking for a slightly more intuitive explanation/example of hysteris to understand the use of a MT NDT Yoke etc. You nailed it sir. Couldn't be better, Thank you

[@DougLand]

I watched a few of your videos. They may take a while to finish because they are so comprehensive because of the subject matter. But when I get to the end of the video, I seem to love hitting the AH-HA moment. Keep it up!

[@joaogonzalez4082]

Hi Doc, I came across you video here, very nice introductory view about magnetic momentum and domains. Just want to freeze one thing, as you know "saturation" (B=nM) is only theoretically achieved and for most ferromagnet materials, even for non soft ferrites, will not align all domains in a "saturation" scenario as you described here :) . Good job.

[@transdata3035]

For the first time I really understand what the heck Hysteresis is all about. Thank you! (excellent metaphor!)

[@doudsbass]

Nice, especially your clicking device 😁 Also a remark about your voting people analogy for the micro/macro organisation of magnatised objects : I liked it, I think Theoria Apophasis (Ken Wheeler) would call that coherency and point source. You might like his very simple Physics based on pressure mediation in the Eher (inertia and losses of inertia). It's kind of piratry for current scientists but he says that Tesla and Steinmetz already said similar things. Anyway, thanks for the lesson 😊

[@nathanturner21]

Damn I wish I was as excited about magnetostatics as you. Cheers for making me smile during a torturous library session

[@AD-ox8bv]

Brilliant explanation, its made a lot of things fall into place about magnetism and greatly helped with my studies for next months exams. Thanks a million, i don't know if you are but you would make an excellent teacher.

[@jacobhornsby5459]

Great video! I'm in NDI school right now and we're learning about Mag Particle Inspections, specifically the Hysteresis Loop. All of our material is extremely technical and sometimes hard to understand or interpret (without a dictionary or prior knowledge) So, this video explained it to me very well.. A little sporadic but it definitely got to me! Thank you!

[@sarahappy3204]

13:09 oh thanks that you mentioned H. I was like „nice, but why is it B?“ so yeah. It‘s a great video for understanding the basics.

[@HieuNguyen-gc6kx]

wow, amazing lecture on hysteresis

[@miskeen_0]

Why is he posting no more??

[@bbbf09]

Good vid. Thought I would add rather than just mechanical shock you can of course reset the bolt to its magnetic history 'year zero' by heating to a defined temperature - known as the Curie temperature. For steel its about 900 deg C (I think)

[@munchmafuziquchi2965]

Of course you meant poop factory.

[@RioPradipto]

wow. I missed a class, and don't understand what does this Hysteresis on my script even mean. Thank you so much. Don't realise that video from almost 6 years ago is still very very helpful. Thanks again

[@MsZuckar]

omg...you are still making new video....u made me love physics more sir!...

[@johnezekieltandog1885]

"Who knoooowws?" HAHAHHA best part, you're a cool prof I guess, if you were hehe

[@murtazahatim6675]

You sir, saved me from a lot of head scratching and hair pulling! Loved the video ☘

[@gameforlife8542]

Damn i wish you were my teacher. :o Great explanation !!

[@SehajSingh94]

I just watched this at double speed... Best 10 minutes of my life :'D

[@Nick-yn3yt]

What a great and funniest teacher he is? If my school teacher study us like that I cant get fail in my exams He really deserves a subscribe

[@Sk8n2Enjoi]

Since nature "prefers" not to have concentrations of energy, you must make her very upset. Your enthusiasm is awesome!

[@yugenbear4895]

thanks a lot! really nicely explained, keep up the good work

[@faridmammadov7464]

Explanation is awesome but there was a huge mistake at the very end of video from 20:00-20:10. It is not the residual magnetic flux density Bres which distinguishes the hard and soft magnetic materials. It is the coercive force i.e. magnetic field intensity Hc distinguishes the hard from soft magnetic materials. The wider the graph in lets say x direction the more the harder the material from magnetic point of view.

[@nickqiao4764]

Thanks for lecture vivid

[@Hino_55]

so "B w/o IRON" means "IRON w/o magnetic field (B) caused by the electromagnet" i.e. electromagnet is where the Bext comes from & "Bresulting" means the resulting magnetic field in the iron got me confused about the label for a sec, great vid btw!

[@anmolrocks247]

Doc...this is one of the best physics concept explaining video i have ever seen!!!! You are great!! 👍👍👍👍

[@jamshi55]

Nice Presentation :). Keeps the energy of audience throughout the presentation

[@parthchopra2811]

I can bet my life’s fortune that there ain’t a better explanation than this in the whole of physics!!! This and every other video of yours sir, is a MARVEL, no less!!!!!!! Thanks a lot for the excellent work and lucid explanation :D

[@richardpaulson8954]

Yes roughly but curl at sharp corners of domains boundaries form stable vortexes. Farther away it's like you say. So what can magnetic pixels do with vortexes as a macro particles and what kind of resonant cavities can you form with m pixels? Can you shape saw devices dynamically? Can you beam steer for directed comms with say gammas beams.

[@euanmeston]

"You win!" Subscribed.

[@chiragkapoor3331]

Very helpful and interesting

[@minamyoui1682]

You win! Lol. And normal people call it saturation made me laugh.

[@khaliffoster3777]

So, there is a force, the higher level that is three of it, so you force to center which there is resistant field so it is huge relative to external force that is Iron that is thru the center like scissors and black pole thru a ring of box thing. So, at the points that is three of it so there is two saturation which is + and other is -, so the point is a force to compress of three energy, so those three energies is domain field, which has one arrow left and one arrow right, and you add the arrow from those two so it is a switch arrow base on center arrow that is already there, so the internal arrow is polar direction that is inner, so the external which you cause the force to add or subtract, so when it gets saturation that means the previous left at center change to right fully, same as another side of saturation, so when it gets full, the energy is compress of three energies. So, there is power base on high parallel direction, like a magnet which cause push another magnet, and if magnet hit you, you get hurt, so high parallel domains is high, but you change it from low to high, which from random to order, or old order to new order. So, you are causing the work that is base on center that is resistant field that is huge at center, so the weak to the strong, so need both to gain domains that is you are weak and there is a strong enemy so you need to beat from inside so you get smart so you gain the enemy into your side so the enemy betray the country so become your country, so you win so you saturation, so that means you steal the energy from center to left or right side, that is - or +, so it gets smaller and the weak get strong, so it is a switch from weak to strong, so balance out. So, compress is stealing the center as you compact into one point so you have higher domains from the center that has high random, high order of left or right, so the center switch to your side as you will win and beat the center country, so the external country get strong, so the weak become strong. So, when you compress so you have higher denser domains compare to center that is strong but wide spread, so you become higher compact in per space, compare to lower compact in per space of the center, so higher space density, relative to lower space density. So, when there is alter of two domains during the process there is eddy current as it feeds the current to other side as an exchange so pull or repel each other, so cancel out, so there is fighting between two enemy but you will win as you domains them so there is high lost of eddy current, but high gain of magnet field. So, you fight and persuade the enemy to your side, so you will success so you are best war planner so you success beating everything one. Summary: Two enemy, external enemy to center enemy, so the external will gain the center but the external is weak as correspond to soft iron, to center that has huge domains, so I have low domains, so domains with me so I fight and persuade to gain them so we fight as correspond to eddy current as switching domains, so I get stronger by persuade so constant force from left to center, and to right of center, so I get stronger surpass the center with higher domains in lower space per densities relative to center that is high space per densities, so I success to other side that is negative saturation. Of course happen again on other side to positive saturation when the center raise in strength, so need to beat them again, so the fighting of back and forth will constant for years so the magnet is in balance as hold each other that is eddy current to feed each other but no gainer, so it is best to fight than to keep it so I can keep working and success in small way so prefer in my enjoyment in waring the enemy. Ok, so there is no killing but only gaining or losing, but it is not a dead or alive, but pull to our side or lost the pull to their sides, so I attract them to win, than domain to repel the enemy that is in during the repel, I gain as attract all enemy so repel completely. So, in connect of eddy current, so there is a domain of gaining of other but not, so back and forth, so cancel out each other, so attract to repel, so in between the primary center, so left center, then to point of left so gaining which is overcome completely to attract all, as repel enemy can't repel, so the repel is lower as domains is weaker so my domains success so it is saturation that is left saturation.

[@valentina7901]

10 years ago but still useful😁👍thank you doc schuster

[@SHONSL]

Best hysteresis explanation!

[@user-ib4bg9kg5s]

Great analogy of taking over England, I love your style

[@cindiecapelduran2929]

Can you please replace all my teachers? Excellent video, I understood it so well. THANKS!

[@justadreamerforgood69]

Follow professor Adel Gastli if you are learning Electrical machines

[@alokverma3311]

HELPFULL VIDEO FOR BEGINERS FOR BH CURVE STUDY ...THNX

[@takshashila2995]

Did I just learn how to conquer England alongside learning Physics and some jokes?cool.

[@thijsg717]

you're an enormously good teacher

[@averelrebello8513]

u are the best when ti comes to explaining concepts

[@mr.priyatham]

fantastic....had a great pleasure to listen without any deviations......Thank u Doc!!!!!

[@namankarn1504]

I love it when he says.. ' magnet's going on an adventure.' Hence a new subscription added to my list.

[@teragreg2927]

Wow! Why is the direction of the magnetic field around currents so predictable? I guess what I’m asking is why do they always point one way (I.e., clockwise around a current), rather than the other way? I know some people say this is convention. But the universe really seems to operate based on the right hand rule, it must more than a convention. Is there something quantum that is causing the field around a current to always be the same predictable, preferred direction?

[@Sthern34]

Thank you for the great explanation. It helped me a lot. What i'm facing now is.. how comes that the material can't go back reversibly when you reduce de Bext ? what happen inside the material?

[@sundarbe]

You deserve a lot more subscribers, and you got one more.

[@dishatiwari285]

+Doc Schuster I have questions related to diamagnetism. Let's take Bismuth ( a diamagnetic material) and wood. Both Bismuth and Wood have the net magnetic dipole moment as 0, then why does Bismuth act as a diamagnetic material, but wood doesn't act like one?

[@jingyuanwang2464]

this is the greatest video in the world you don't how enlightened right now that I understand everything

[@graphene1487]

"Which way you gonna magnetize?" so funny :)

[@avachavoshi574]

Very clear description of magnetic hysteresis. Thank you very much.

[@bhattaraib58]

Doc Schuster always saving me from all the small things i forget or didn't understand !!! Thank you for the great videos !!!! And hope you make video on Ampere's law quickly as my exams comming and i am like addicted to your teaching i dont like others videos !!! Thanks for great videos !!!

[@bhattaraib58]

Ampere's law and its application if you please !!!

[@muhammadsuleman-bf5oh]

excellent

[@donalmoloney2695]

Why is the name for the graph you drew if I wanted to find more about it.

[@amjadameur3373]

You have a such good accent , i like the way u explain , tnx

[@Crisdapari]

What a Greek oracle when "England will take over itself" on 18:10 LOL! Just wait for 2016 and 2020. XD

[@misterlocapone6604]

Very helpful video! Great explanations!

[@ChaitanyaSrikar]

Can you please tell me the difference between M-H and B-H curve

[@cheyuna]

Thank you so much for this video!! It really helped survive my final exam :)

[@melody3891]

I liked the video before i even watched! Title xD So well explained! Thanks!!

[@Jeterify]

This was a really entertaining and useful video, thank you! :)

[@xlxs1]

After saturation, isn't Bresult supposed to still go up slowly (and linearly) as Bw/o iron increases?

[@georgia9926]

Oh man this was so helpful thank you so much, I'm currently learning this but I'm an exchange student so it's all in japanese so often it's really difficult for me to understand the concepts with the language barrier, so my brain's kinda tired at the moment but this made it so clear as well as being absolutely hilarious! Thankyou!!

[@dorientmabioko2791]

Alors comment on fait pour suivre la traduction française faite par youtube?

[@babypancakes6882]

he had a small scissors last time and now he has a big scissors. get it haha

[@ME-bz9fd]

Beautifully explained

[@HM-dm3qg]

you are best teacher ever. i used to think walter lewin was good. you are 1000 times better than that man.

[@dylanreinboth9577]

*Sincere golf clap* Thanks, excellent presentation. You are a unique talent.

[@purvai4701]

THANK U FOR THE TITLE ND EVERYTHING

[@shashidarGonnagar]

Good hyzterisiz vid!! and 17.37 the height (residual) is used for magnets? I guess

[@xplodnow]

Useful Video! i have a qn though, is the domain boundary the same as the grain boundaries in the metal by any chance??

[@DocSchuster]

xplodnow Often, yes! It can, of course, be more complicated, though. Great question.

[@xplodnow]

Doc Schuster awesome. Thanks!

[@VV-oo2dv]

Great explanation dude!!!! You rock!!! If you have time upload a video on alternating current and direct current

[@b.s.bhumika5830]

Why didnt i meet you earlier You r perfect to my pratical thinking Thank u..so much......

[@nadjakonig5166]

Thanks from Germany! Great Video!!

[@elisampley7598]

Please do a video on why hitting it restores the natural state. There is something goofy about saying that scientifically. Does it have to do with the vibrations? And do those vibrations actually affect anything on the smallest scale? I would think any "waves" formed would be much too large to effect molecules or atoms directly.

[@MatheusSilva-dragon]

0:59 Oh my ghost! Why are these scissors so big?! 14:35 Really?! Awesome! Thank you very much, doc! You've explained hysteresis in such an intuitive way that if I go read in a book about it it will only increase what I have learned today! And thanks for the tip about England! Mwa ha ha ha!

[@dungtran-lh8lu]

Sorry, at 20:00, I think soft and hard magnetic material were classified by coercive force, not by residual magnetism, am I right?

[@DocSchuster]

Oooh! Great point. There's often symmetry there, no?

[@dungtran-lh8lu]

yes, i think so

[@michaelheraghty9321]

absolutely well done here!!!

[@deiu9999]

Thank you sir, I like your sense of humour! :)) I also mannaged to understand how things works with this stuff called hysteresis :)

[@LiquidMetalLifeForm]

This is one big heart for you man of science

[@charanm1093]

Doc please can you send what exactly hysteresis mean