How Magnets Work


Stockbyte/Thinkstock
Stockbyte/Thinkstock

You can stick them to the fridge or use them to transpose sound to tape, whatever they are used for magnets are surprisingly interesting. And knowing just exactly how and why magnets work will make you more interesting, which is why you should listen to this episode of SYSK.

Josh: Hey and welcome to the podcast. I'm Josh Clark with, guess who? Tell them, tell them who I'm with Chuck. Oh, Chuck. I'm with Chuck. Jerry's in the room as well. Since the three of us are together in this room we have, tell them stuff you should know, chuck.

Chuck: Stuff you should know.

Josh: That's right, the podcast. I am so excited about this podcast.

Chuck: I know you would be.

Josh: So much so that I'm worried about it because as you know and anybody who even occasionally listens to The Stuff You Should Know or is aware of, the more excited I get about a topic the poorer job I do at explaining it.

Chuck: Yeah.

Josh: See, I already did it. I should have said the poorer the job I do.

Chuck: Yeah.

Josh: It's true, so I'm just going to remain calm.

Chuck: Okay.

Josh: All we're talking about is magnets after all you know?

Chuck: That's the way I feel.

Jerry: We usually balance each other out nicely like that.

Josh: You don't think that there's some, a certain cache, to walking around, understanding how a magnet works. Do you realize what percentage of the population you're a member of, for knowing that. Maybe, maybe, and this is a guess, .0029 percent of the human population.

Chuck: Knows how magnets work?

Josh: I don't know anybody else, until we selected this and started reading it besides Tracy Wilson who knew how magnets work.

Chuck: I think you are underestimating the curiosity of the general public for people to look up this stuff on their own.

Josh: Alright. I would like to hear from people. If you already knew how magnets work and if you're listening to this?

Chuck: You act like if we don't tell people this and they're just dummies walking around.

Josh: I don't think that. That's not at all what I think. I guess this is kind of like -

Chuck: We'll get corrections on this and I think that will prove people know this and more.

Josh: If you're a physicist whose specialty is the electromagnetic power then yes, we're going to mess things up, it's true, but we have a general, good, well I'd say fairly detailed idea of why magnets exist.

Chuck: That's right.

Josh: We're going to explain that to everybody.

Chuck: It's all because of [inaudible].

Josh: Not in any way shape or form in a condescending manner.

Chuck: No, no, no, no.

Josh: All we do is research.

Chuck: That's right.

Josh: It's not like we're making magnets here.

Chuck: No.

Josh: We're just talking about them.

Chuck: You know they discovered these in Magnesia in Greece, did you know that?

Josh: What?

Chuck: Magnets, like natural magnets.

Josh: Yeah, like lodestone.

Chuck: In Magnesia, in Greece.

Josh: Is that really a place?

Chuck: Yeah.

Josh: Magnesia.

Chuck: Absolutely.

Josh: You're not pulling my leg.

Chuck: Nope.

Josh: Okay. But it was Lodestone, a type of magnetite?

Chuck: Yeah, it was magnetite.

Josh: It's the strongest naturally occurring magnet, right?

Chuck: Yeah.

Josh: Like you can attract a paperclip just with this rock.

Chuck: That's pretty cool.

Josh: Yeah it is. Even cooler though are the ones that humans have conquered and mastered and owned.

Chuck: That's right.

Josh: Because all the magnets you come in contact with on a daily basis, maybe a weekly basis have been manipulated by humanity.

Chuck: I never come into contact with magnets.

Josh: You know something? It's hard to find a decent magnet these days in an average store. You have to mail off for them.

Chuck: Oh yeah?

Josh: Yeah.

Chuck: I don't have refrigerator magnets because the stainless steel fridges, you can't put a magnet on them.

Josh: That is so weird.

Chuck: You can put it on the side so we have a few - you get magnets over the course of your life whether it's - the pizza delivery guy has a - like we have one in the shape of a pizza slice with their number on it.

Josh: You do.

Chuck: That's on the side. Our vet - we have a vet magnet.

Josh: In the shape of a pizza slice with their number on it.

Chuck: Random people have given me magnets here and there which I'll throw up there on the side.

Josh: That's good. Those are nice mementos. You ... those sometimes.

Chuck: We got one in Guatemala one time.

Josh: You did? That's nice. That's great Chuck.

Chuck: Anyway, I don't have a lot of magnets or experience with magnets, but I understand them.

Josh: Now that you say that, I realize that I have more experience than I realized with magnets. I mean I do have a pretty good magnet collection on our fridge.

Chuck: Well there you go.

Josh: It is - it always struck me as weird that stainless steel, you couldn't put a magnet on that. Now I understand why. Stainless steel is not a ferrous metal.

Chuck: That's right.

Josh: You have to have a ferrous metal like something say, iron, nickel, cobalt, aluminum even.

Chuck: Really?

Josh: I think so because there's a type of magnet called the alnico magnet. That's aluminum, nickel, cobalt alloy.

Chuck: If you've got a really good guitar amp, you might have an alnico speaker.

Josh: Is that right?

Chuck: Yeah, they're pricey.

Josh: Oh yeah, I can imagine.

Chuck: You can buy the speakers separately and switch it out in your amp and make your amp sound better which I've been meaning to do for years but they're just kind of pricey. It's like $400.00 for the speaker.

Josh: How's the sounds?

Chuck: I'm told it's great but music guys here, much more than I do, like real, real music guys, they're like, can't you hear the difference and I'll be like yeah, sorta.

Josh: Are these music guys also alnico speaker salesmen?

Chuck: Yeah, probably so.

Josh: Let's get - so this is what I like about this article. It goes like basic to specific.

Chuck: Yes.

Josh: You can start with the basics about magnets, they attract specific metals; as we said, typically ferrous metals. They have a north and a south pole, all magnets do. There's no north and east poled magnet.

Chuck: Yeah, and the earth is the biggest magnet of all I guess.

Josh: It is, at least on earth. Opposite poles attract one another. Like poles repel one another. They hate each other.

Chuck: That's right.

Josh: Magnetic and electrical fields are related and we're going to explain why.

Chuck: I'm so excited.

Josh: In magnetism, I think I said electromagnetism earlier so you can put your email away because I'm correcting myself.

Chuck: Yes.

Josh: Is one of the four fundamental forces of the Universe, right?

Chuck: That's right.

Josh: With gravity and the strong and weak nuclear forces.

Chuck: That's right.

Josh: That's magnets.

Chuck: That's a great intro. Magnets, the object itself - or, a magnet is an object in itself that produces a magnetic field and it's going to attract, like you said, ferrous metals. There can be permanent magnets aka hard magnets and they always have a magnetic field going. Then you have the temporary magnets, aka soft magnets. They just produce a magnetic field when they're in the presence of a magnetic field and only for a short time and then for a little bit thereafter once it's gone.

Josh: Electromagnets, when you apply an electrical current to some magnets they become magnetic.

Chuck: That's Right.

Josh: If you have a doorbell you probably have an electromagnet in your house.

Chuck: Yeah, the doorbell?

Josh: I looked it up it's more complicated than you would think. It's like a Rube Goldberg-esque contraption that is apparently pretty standard and uses electromagnets, it's neat. Actually if you're interested in that, there's an article how doorbells work on howstuffworks.com.

Chuck: Isn't it weird that the door - or maybe it's just me as a misanthrope. The sound of a doorbell now is not like, oh I wonder who's here; it's oh crap, who's here?

Josh: Right.

Chuck: Because no one just drops by anymore.

Josh: Right, either that or like, they know.

Chuck: Yeah.

Josh: Yeah.

Chuck: Yeah.

Josh: So Chuck, the magnets that you typically have, like your pizza boy magnet or the circle ones are probably the best example, just a ring, that magnetic ring that you see and grew up with. Those are a specific type and they're called ceramic magnets.

Chuck: That's right.

Josh: They're probably the weakest magnets commercially available except for the pizza slice ones.

Chuck: Right.

Josh: That's almost like a sticker.

Chuck: Yeah, I mean it's connected to, or it's got a topper on it, with printing. A topper?

Josh: That's the word for it.

Chuck: There's a word for it I couldn't find. The topper, the pizza slice topper.

Josh: With the ceramic magnet, it's magnetic material mixed with ceramics and it kind of cuts it. It makes it a little weak.

Chuck: But good enough to stick on the fridge which is all you're looking for.

Josh: And it's cheap.

Chuck: It's cheap. You've already mentioned alnico magnets which are more expensive. Like you said, aluminum, nickel, and cobalt and they are stronger than ceramic obviously, but not as strong as the ones we're about to talk about like neo-dimian magnets.

Josh: Yeah, or samarimiam.

Chuck: Samariam.

Josh: You've got to be kidding.

Chuck: Samariam.

Josh: Samariam. Both of those magnets incorporate rare earth metals which are extremely magnetic, or when combined with an alloy can be very magnetic.

Chuck: Yeah, that's true. Now they even have - and this is something I never knew - they have plastic magnets called magnetic polymers and I guess those are for use in just very certain applications, like cold temperature applications.

Josh: Yeah, or that's what's on your pizza slice magnet.

Chuck: Or, it says they pick up very, only very lightweight things like iron fillings so I wonder if that's what you use with your - do you remember the little toy kids thing where you could, had a guy's face and it had the little iron fillings and you could move it around and make a beard or a mustache or whatever?

Josh: Yeah, sure.

Chuck: I bet that's what that is.

Josh: What was that called?

Chuck: I don't know.

Josh: Old-timey toy #273.

Chuck: Not an Etch-a-Sketch, not a Hugo, something like that.

Josh: Why was it that anybody who had a beard from the 1940's to the 1960's, any child's toy, was the most disturbing looking creature you could come up with?

Chuck: You think?

Josh: Oh yeah, have you ever heard of Rush Tin Dolls?

Chuck: No.

Josh: They had, they were this very successful toy company and they came out with a line of hobo dolls that were the scariest things you've ever seen in your life. They were meant to damage children obviously.

Chuck: Or keep them from hopping trains, probably.

Josh: I guess.

Chuck: You know?

Josh: Yeah.

Chuck: Play with it at home. Don't go out on the road.

Josh: This is what happens if you hop trains.

Chuck: Interesting.

Josh: I made a blog post actually called 27 of the most unintentionally terrifying dolls you've ever seen or ever created.

Chuck: That's like almost every doll in my opinion.

Josh: You should see the slide show, it's pretty good.

Chuck: I'll check it out.

Josh: Let's talk about making magnets Chuckers.

Chuck: Alright, well you talked about lodestone, a form of magnetite, and that is the natural, strongest natural magnet.

Josh: You don't have to do anything to it.

Chuck: Nope.

Josh: I guess the discovery of lodestone and the fact that it attracted metals made people start to tinker around with it. I guess around the 12th century people figured out that if you took a little iron pin and you took some lodestone and you petted it in the same direction, preferably in a northern direction, you could magnetize that iron filling. If you suspended it in something like water in a leaf, for anyone who's seen that movie with Alec Baldwin and Anthony Hopkins, The Edge. They magnetized a needle and put it in a water-filled leaf and it - they figure out which way was north through that.

Chuck: I knew I had seen that before.

Josh: That's basically magnetizing a pin using lodestone. That's how the earliest compasses were made.

Chuck: Very cool. What's going on here, and this is sort of the basis, and we'll break it down to a more molecular level. What's going on here is something known as a region called a magnetic domain. It is actually part of the physical structure of any fero-magnetic material. We're talking again, iron, cobalt, and nickel largely. Each one is like its own tiny little magnet. Right there it's got it's only little north pole, its own little south-pole. If it's un-magnetized, then this stuff is just going to be random and pointing in all different directions.

Josh: Right, the domain has its own north and south pole, but it's not necessarily aligned with the north and south pole on earth.

Chuck: Right, they're just kind of askew. If it's magnetized they're all pointing in the same direction.

Josh: Right, yes, that's pretty much all you have to do is figure out how to get all those magnetic domains to align in the same north-south line.

Chuck: If they're not they're just canceling each other out.

Josh: Exactly. The more domains that you have pointing in the same direction, the more powerful magnet that you have. In each of these little domains you can just kind of - I almost see it as like a little pocket in the molecular make-up of this, like an iron. The north pole of one domain flows into the south pole of the domain in front of it if they're all aligned. You add a bunch of these up they produce one large magnetic field for a magnet as a whole.

Chuck: Yeah.

Josh: Right?

Chuck: Yeah, which explains why if you do the old trick in elementary school where you bring one magnet close to the other, it will either repel it or snap it together like one larger magnet.

Josh: Right because the force, this magnetic force is going into - out of the north pole of the magnet and into the south pole of the magnet in front of it.

Chuck: There's something very dirty about that.

Josh: It is, right. Or if you take the north pole of one magnet, the north pole of another magnet and you put them together, they repel one another because their magnetic forces are flowing in opposite directions and pushing one another apart which is kind of funny because this is how magnets work but it bears such a striking resemblance to like, something they would have come up with in the 16th century like the force flowing out.

Chuck: Yeah, this invisible force.

Josh: Right, it's witchery and this is why magnets won't be brought together.

Chuck: People would come and drag us out of here and toss us in the lake to see if we float afterward. We could stop there and you would have a pretty good idea of things, but we won't. We'll continue on.

Josh: We'll go a little more in detail, huh?

Chuck: That's right. If you want to make a magnet, you have to get all these magnetic domains flowing in the same direction; just like we were talking about earlier when you rub the needle on the magnet. You expose it to this magnetic field and you're getting these suckers to align in the same way and then boom, that is one way that you can get a magnet.

Josh: Right, and there's different ways of doing this. You can place it in a magnetic field in a north-south direction. You can hold it in a north-south direction and hit it with a hammer.

Chuck: Yeah, that's crazy.

Josh: It is a little crazy. You're physically jarring these domains into alignment.

Chuck: Yeah, and they're like huh?

Josh: Yeah, oh, okay, I'll point this way then. Or you can pass an electrical current through it.

Chuck: That's kind of a cheat.

Josh: They think that this is where lodestone came from. Either it was when this rock formed, the magnetite formed from a lava it was aligned with the north-south pole of the earth so it became magnetized, or it was struck by lightning so an electrical current passed through it.

Chuck: That would be pretty cool.

Josh: It became magnetized as a result.

Chuck: That seems likely.

Josh: Right. Today the most common method of making magnets is to place them in a very strong magnetic field and boddaboom boddabing their domains start to wind up.

Chuck: Yeah, there's going to be a little bit of a delay though. I saw this on a YouTube video. This guy - there's a really good one, I can't remember what it was called where the guy broke it down. Whenever it's stuff I don't understand I always type kid science and then I look and see what videos are available.

Josh: Yeah, yeah, no it's good.

Chuck: It really helps out. There will be a delay called hysterisis, or hysterisis, that's basically just the time it takes for the field to change direction and all align itself.

Josh: Right because when you get these domains going, the ones that aren't already lined up on a north-south pole, they just rotate around and do a little crazy spinning until they land on it. The ones that are already aligned north-south, they grow bigger.

Chuck: Yeah, become more robust I guess?

Josh: Yeah, and as a result other ones, the walls between smaller domains will shrink. So you have large north-south domains and then even the smaller ones are now probably polarized along that north-south line. You have just created a magnet.

Chuck: Yeah, and here's what I think is one of the really cooler aspects of this is how strong your magnet is depends on how hard it was to get these domains to move in that direction. The harder it is the longer it will stay magnetized which sort of makes sense. It's almost like that - it was so stubborn to get going but then once you got it going in the right direction it was then stubborn undoing it, that action.

Josh: Right, which kind of makes you wonder if over enough of a time span will any magnetized material eventually lose its magnetism.

Chuck: Just left alone?

Josh: Yeah.

Chuck: Huh, that's a good question.

Josh: There are things you can do to de-magnetize things. You could take a magnet and put it in a magnetic field that's polarized the opposite direction.

Chuck: Yeah, that's kind of mean.

Josh: Yeah, you can boil it alive which is also very mean and heat it to the point where it loses its magnetism.

Chuck: Yeah, The Curie Point, the guy in the video tested this. He had a paperclip on a string tied to the table and then the magnet was like a foot off, so it was just like doing. Then he took a -

Josh: Was it a Jerry Lewis [inaudible]?

Chuck: Then he said Dean, bring me a lighter. He got a lighter and heated up the paper club and then you see it start to shake and then eventually it just poop, fell.

Josh: That is a weird story.

Chuck: Eh, he de-magnetized it, using the Curie Point.

Josh: So okay, again, we could stop here. I think everybody understands how magnets work, right? There's little magnetic domains that are in all kinds of crazy directions and then when you expose them to a magnetic field they line up together and they produce their own magnetic field around that magnetic material and then there you go. It flows out of the north and into the south. Magnets, right?

Chuck: I would like to see a survey. I wish you could take an instant survey of people that - half of them are going, go, go, go, and half of them are like, I'm good, that's all I need to know about magnets.

Josh: I think our listeners are pretty curious folk.

Chuck: Okay, so we're going deeper and Tracy Wilson, our site manager here of stuff you miss in history class now. She wrote this one and she's so thorough. She has a very nice little pun in this section called shipping magnets. Get it?

Josh: Oh.

Chuck: Shipping magnet?

Josh: Yeah, I got it now, I didn't notice that before.

Chuck: Yeah, it's a pun. What she's talking about in this section though is interesting in that very large magnets present a lot of problems because they're super strong and you can't just throw it on a truck and drive it across country. It will disrupt everything. Very specific precautions have to be taken when delivering large magnets used for certain industrial applications, one of which is, they have machines that - because it will pick up all this ferrous material along the way.

Josh: Right.

Chuck: They have machines when they get there to remove all that stuff.

Josh: I mean imagine if you're shipping it in a truck and the truck is made - or it some kind of iron alloy in it and you have a huge industrial magnet. How are you going to get that off of a truck. You're not. They magnetize these materials on site typically, right?

Chuck: Oh, is that what they do?

Josh: That's what I understand or else they just rely almost exclusively on electromagnets which become magnetic when you pass a current through it.

Chuck: I thought you were going to say man power. Get me those ten guys.

Josh: American ingenuity, that's how you do it.

Chuck: Pull! It's stuck sir. Well, speaking of sticking, we're going to break it down to electrons which -

Josh: The atomic level.

Chuck: This is bound to happen because that's where it really all starts.

Josh: I was just saying, electromagnets, they become magnetic when you pass a field of electricity through them, or a current. All electrical current is, is a flow of electrons. Movement of electrons produces electricity. Electricity and magnetism are very much related. This is why, because on the atomic level of a ferrous material, iron, nickel, cobalt, those are the big ones.

Chuck: Let's call it the big three.

Josh: Let's talk specifically about iron. In an iron atom, there are, around its orbit, in its orbit, there are electrons moving around.

Chuck: Yeah, they spin upward or downward.

Josh: Typically they're paired. When you have a pair of electrons, one's spinning upward, one's spinning downward, there's never any other way. There's no pair of electrons that spin in the same directions, always opposite.

Chuck: That's called the poly-exclusion principle. It's just not possible.

Josh: In iron you also have four un-paired electrons that all spin the same way. Those ones that are paired and spin in the opposite direction, they cancel one other out. These four spinning the same way, they produce a magnetic field. A very, very, very, very, very tiny magnetic field, but a magnetic field nonetheless, right?

Chuck: This is very unusual for these unpaired electrons to be spinning in the same direction. That's why it only happens in things like iron, cobalt, and nickel.

Josh: Right, exactly, that's what makes them ferro-magnetic material. Potentially magnetic because they have these unpaired electrons that are spinning in a certain direction, right?

Chuck: That's right.

Josh: Then, because these things are spinning in the same direction, they attract other atoms to kind of line up, that are spinning in the same direction, to line up nearby. Then those create what, domains.

Chuck: Well, a moment, they have a moment.

Josh: Oh yeah, I forgot the moment.

Chuck: It's called the orbital magnetic moment. I get it, maybe that's just when they realize hey, we're all partying in the same way, we're all spinning downward.

Josh: Right, we all like slacks.

Chuck: Yeah and hey, we've got a magnetic field all of a sudden. It's small but let's get a bunch of other ones and let's create a larger one.

Josh: Right, and that moment it describes the force and I guess the power and the direction of the spin.

Chuck: Yeah.

Josh: Yeah, when you have a bunch of them having the same moment they kind of line up around one another when iron forms.

Chuck: That's right.

Josh: Then that causes the domain or that creates the little magnetic domains in the material.

Chuck: That's right. If you notice, the materials that make good magnets are the same materials that magnets attract. Then it's because they attract unpaired electrons that are spinning in that direction. It's the same thing. You can also have something called dimagnetic which are unpaired electrons creating a field that repels instead of attracts and then some materials don't react at all with magnets.

Josh: Like pine straw.

Chuck: I think now is a time for a word from our sponsor.

*stuff you should know*

Josh: Chuck -

Chuck: Yes.

Josh: When our entire team can get together, you, me, Jerry, Casey, Joe, everybody - we can get some stuff done man.

Chuck: That's right, but we all have to be in the same room in order to get that stuff done so we can look at each other and talk about things, right?

Josh: Yeah, but gathering in the same room, that's tough. Everybody's got their own schedules. People have dogs they have to let out. There's just - people have work schedules that we need to work around.

Chuck: Thank God there's something called Go To Meeting with HD Faces because we can get together online, altogether on the same screen, share documents with each other, in HD, and it's just like being in the room with them. It's even better because you can't smell each other.

Josh: Exactly and the built-in HD video conferencing makes us - it's like we're in the same room. It's also easy to join a GoTo Meeting anywhere by using your smartphone, your PC, your tablet -

Chuck: That's right and folks we've got a deal for you. Try GoTo Meeting free for 30 days, don't wait for the special offer. Visit to gotomeeting.com, click the try it free button, use the promo code stuff, that is s-t-u-f-f at gotomeeting.com.

Josh: Nice Chuck.

Chuck: Alright, back to magnets because there is still more to go.

Josh: I mean, now everyone who's listening to this understands magnets on an atomic level. It's the spin of electrons.

Chuck: It's physics, my favorite thing. This one actually appealed to me more than usual, physics wise.

Josh: Same here. Remember the physics of surfing?

Chuck: I do. People measure magnets to see how strong the magnetic field is using something called a gauss meter. Flux or webers are the, what would you call that, the unit of measurement.

Josh: You measure flux in webers. Flux is a line of magnetic force coming out of it.

Chuck: Oh I botched that.

Josh: That's alright.

Chuck: The density of the flux is measured in either tesla or gauss with tesla being 10,000 gauss, which is pretty cool that you get a unit of measurement named after you, if you're Tesla.

Josh: Yeah, you better if you're Tesla you did a lot of cool stuff.

Chuck: You can also measure it in webers per square meter, but really, who wants to do that.

Josh: Yeah, Canada probably.

Chuck: The magnitude of the field is measured in amperes per meter or something called orstead.

Josh: Yeah, I like orstead. I'm a fan of orstead and I also like flux and tesla's pretty awesome too.

Chuck: Where do we use magnets besides pizza reminders.

Josh: Or doorbells.

Chuck: Or doorbells.

Josh: Of course.

Chuck: Or speakers.

Josh: We use them to - if you were in cassette tapes back in the day, brother, you were into magnets.

Chuck: Oh yeah, heck yeah.

Josh: We also used them again in compasses, burglar alarms, electric motors, we use them to provide torque.

Chuck: Yeah, car speedometers. If you have an old fashioned cathode ray tube television set you're using magnets. Did you listen to cassettes?

Josh: Sure man, I grew up in the '80's.

Chuck: Okay, I was just - I wasn't quite sure, you're a little younger, but I didn't know. I was a late adopter.

Josh: Of cassettes?

Chuck: Oh no, of everything because what I would do is I would have a big collection and then be like ah, I've got all these records so I was late to cassettes and then I had all these cassettes and I didn't want to switch to CD's until all of my cassettes got stolen. Then I was like, I guess I'll get CD's now.

Josh: Guess I'm going CD's. I was there for the big transition from cassettes to CD's. Remember they were across the board $20. $19.99 per CD.

Chuck: In the big box too, remember?

Josh: What a waste.

Chuck: See, look at that.

Josh: Maglev Trains?

Chuck: Yeah, we talked about this. We have a cool, one of our one minute live action shorts online. We - maybe I'll post this when we release this. The maglev train system in a lot of roller coasters and things like that use super magnets to -

Josh: I don't remember that one.

Chuck: Yeah, the maglev train uses it to propel the train forward.

Josh: Yeah, I don't remember at all.

Chuck: Roller coasters use magnets for breaking a lot of times, like new ones.

Josh: The good ones.

Chuck: You don't remember that one?

Josh: We did like a dozen of them in four days. I don't remember that one.

Chuck: I'll send it to you.

Josh: Thank you. The magnetosphere is part of our atmosphere. I guess it's outside of the atmosphere but it surrounds earth in a protective layer that protects it from charged ions known as solar winds. When these solar winds come in contact with the magnetosphere you get something that's called the northern or southern lights. That's what that is.

Chuck: I knew we talked about that at some point.

Josh: In another short.

Chuck: Then our favorite of course, the wonder machine, would not be possible without magnets because it is magnetic residence imaging.

Josh: It would just be residence imaging without it.

Chuck: Yeah, and there's no fun in that. Doctors sometimes use pulse electro-magnetic fields to actually heal broken bones that haven't healed correctly. It's amazing.

Josh: I looked into this. They have no idea how it works on a molecular level. All they know is that if you expose bone or tissue - I think bone's more, bone and muscle maybe are easier to grow - to an electromagnetic pulse, it grows. Even if it hasn't healed after surgery or any other procedure, if you hit it with an electromagnetic pulse it will, you will get a reaction. They're figuring out how to put this in garments for astronauts.

Chuck: Really?

Josh: Yeah because you suffer substantial bone loss on a very long micro-gravity flight. They're figuring out how to weave it into their clothes so their clothes can blast them with an electro-magnetic pulse to make sure they're bone density keeps up.

Chuck: Wow, that's pretty cool.

Josh: They don't know why it works, they just know it works.

Chuck: Cows are pretty happy there are magnets because there's this horrific thing called traumatic - we'll just call it hardware disease. This is when cows eat small metal objects that are in their food. It's pretty awful that that happens, but luckily they have a cow magnet to feed them and it I guess gathers up all the stuff and they poop it out.

Josh: I'll bet that's horrible to poop out.

Chuck: Isn't that what happens?

Josh: Or it punctures - oh, the magnet?

Chuck: Yeah, I mean they poop it out, right?

Josh: Do they poop the magnet out? I don't know if it does.

Chuck: It truly doesn't just stay in the body, does it?

Josh: I don't know.

Chuck: I'm going to look into that more.

Josh: People are known to put their arms into cow's rears.

Chuck: Yeah, some of them have a whole cut into their sides, remember, so they can examine their stomachs.

Josh: Yeah, the one with the porthole. Yeah, that's pretty cool. I'm going to try this one. Traumatic Reticulopericarditis.

Chuck: You practiced that before-hand. Well done.

Josh: So -

Chuck: There's nothing wrong with that. Some people might think practicing hard words before you do a professionally released audio program is a good thing.

Josh: If a human swallows a magnet, that's not good.

Chuck: Yeah, you don't want to do that.

Josh: Cow's intestines and stomachs are different than human's intestines and stomachs. If we swallow, especially more than one magnet, they will basically clamp your entrails together and you will be in big trouble and you will have to undergo surgery to have them removed.

Chuck: That's no good. Parents be cautioned to when your kids are playing with magnets because kids like to swallow things they shouldn't swallow.

Josh: Yeah. Since we talked about electromagnetic pulses being capable of spurring bone loss. Is it spurring or spurning?

Chuck: Spurning bone loss, spurring bone growth.

Josh: Thank you. You would think that people wearing magnetic bracelets or magnetic insoles are getting some sort of benefit. There's no study that's every shown that those things acutally help. Although there are a lot of people out there who believe in static magnetic therapy which is just a magnet on your skin. There is no pulse or anything going off. they think that possibly, the peopel who are adherents to this, think that it's either attracting iron in the hemoglobin -

Chuck: That kind of makes sense.

Josh: To improve circulation. Or it has some sort of effect on the cellular structure in the body. That's why it helps your back, insoles help your back or a bracelet -

Chuck: Helps your arthritis.

Josh: Yeah, but again there's no studies that suggest this.

Chuck: It's big money. Americans alone spend about $500 million per year and world-wide about $5 billion a year on magnetic treatments.

Josh: With a B.

Chuck: That's a lot of dough.

Josh: It is.

Chuck: One more thing, magnetized drinking water is a thing now to treat ailments. I think that they have not shown in clinical trials taht that's been proven either, correct?

Josh: Most of the minerals in drinking water are not ferro-magnetic so it wouldn't have anything to do with it.

Chuck: They've found that in clinical trials a lot of the positive benefits come from placebo maybe, or passage of time, or maybe the fact that these insole cushionings are better made, more padded to begin with.

Josh: There's also apparently a device that removes hard water minerals from water using magnets, but apparently again it's not really doing anything as far as Consumer Reports says in a two year study.

Chuck: We had a water softener when I lived in Yuma. I had never heard of that and I was like, a what? It's like, it was in the garage, it sort of looked like a hot water heater and it softened the water, whatever that means.

Josh: Do you know what it did?

Chuck: It softened the water. I think I remember asking my sister what hard water did. She was like, oh you can tell the difference. I can't remember exactly.

Josh: It makes your skin real dry I think. So that's hard water everyone. If you want to learn more about that, type the word magnets into the search bar at howstuffworks.com. It will bring up this awesome and exhaustive article. Also if you're interested in doorbells, type that word in the search bar too. Since I said search bar twice it means that we go straight to listener mail.

Chuck: I'm going to call this military shout out. We don't do shout outs that often. Sometimes we do. We get a lot of requests so don't feel bad people if we don't do your shout out. This is from Trebor. Hey guys, my name is Trebor and yes, that is spelled with a B and not a V and that is a long story that I will tell you if you would like, but that's not why I'm writing in. I am currently serving in the U.S. armed forces and I am stationed overseas. My wife and I recently welcomed my daughter into the world - congratulations Trebor and wife. I got to spend some time with them although not as much as I would have liked to obviously before I had to come back overseas. It's been a really long, tough trip being away from them and even harder on our marriage. I work long hours and when I come home to talk to my wife I really dread talking about work and she really hates talking about herself all the time. That's when I bring up topics that you guys talk about on the show.

I have listened for years and I have turned her onto them as well. I just wanted to thank you guys and ask if you could give a shout out to her in listener mail. Her name is Toni, with an I. Trebor and Toni, Trebor, thanks for your service obviously and both of you, thanks for hanging in there as a military couple, it's tough when you're away for that long. It's quite a sacrifice. My sister and her husband, he's a career Marine helicopter pilot as I've mentioned before.

Josh: Yeah, he's been to Afghanistan right?

Chuck: Yeah and they go for long tours for six to eight months at a time and you do enough of those in your life and you realize you're spending years away from your husband or wife, totaled up, and family and daughters and sons. It's tough stuff so shouting out to you guys, hang in there.

Josh: Thanks Trebor and Toni. That's pretty awesome that we're keeping their marriage happy. we're providing the sustenance to talk about. That's awesome.

Chuck: Exactly.

Josh: If you want to let us know how we have helped your marriage, we're very interested in that. You can also try us on a shout-out. Again, we don't do it very often but it's worth a shout if you really think so. You can tweet to us at @syskpodcast and you can join us at Facebook.com/stuffyoushouldknow, send us an email to stuffpodcast@discovery.com and join us at our home on the web, www.stuffyoushouldknow.com.

Female Announcer: For more on this and thousands of other topics, visit howstuffworks.com.

Male Announcer: This episode of Stuff You Should Know is brought to you by jackthreads.com

[End of Audio]

Duration: 37 minutes

Topics in this Podcast: electromagnetism