 Magnets, truly magic things. These are wonderful for teaching because they do magical things and there's a lot of science behind it. The problem for many science teachers is that magnetism is in the syllabus but they haven't got any magnets or if they like this one, they've gotten so old they've lost their magnetism and they're not really very useful. So this unit is about helping to show you how you can get hold of really powerful magnets for your teaching and with it have fun and uncover a lot of really nice physics. There's a ceramic magnet like this one here. It's incredibly powerful. Where can I get hold of these? Well, let me show you one trick that I've come across. Well, this is where I get my ceramic magnet from. It's an old loudspeaker. I just go down to businesses that fit radios to cars and ask them for all the old speakers and they willingly throw all their junk speakers in my way. The magnet lies there in the back and the problem is how do you get it out of there and let me show you a really easy way to do that. What you need is a screwdriver and you lever it in there and it's pop the rivets and you've got the first stage over. So now our problem is how do we pull these things that are very firmly bonded to that ceramic magnet off. And there's a very nice trick. If you look at it, there's a little ridge there and onto that ridge we take some little nuts and we just put little feet. Once you've got your little feet with those nuts that goes down on a floor, a nice solid concrete floor, you take another bolt and just put it there and then you're going to take a hammer and give it a whack to break the bond. Having banged it, we've now broken the bond on this back plate. Just take a screwdriver and off it comes. It's problem one solve. We've got one side off. We've now got to remove this one. How do we do that? And inside we can see there's a little shelf and that's where we'll put the bolt and knock that one off. So now we've got this lovely ceramic magnet. It's very powerful. And the issue is where's the north pole? Where's the south pole? We know that it's a magnet. And if you take another one, a second one, you'll see it's the faces that attract. Or if I pull that apart, turn one over. I actually can't put it together because it's just too strong. So clearly one face is a north-seeking face and the other face is south-seeking. The issue then is which is the north face and which is the south face. And an easy way to do that is simply to tie a piece of cotton on it and it'll swing around but very soon it'll settle. Just stabilize it and you can see it settles in. That's the north direction now. So I know therefore that this is the north-seeking face. Bring another magnet to it and I now automatically know that must be the south face and so on. So you can identify which is the north and which is the south face. Then another very useful thing I find to do is take this magnet, clamp it somehow in a vice or in a crack in a stone or between concrete blocks, something like that. Then just simply take a hammer and give it a hard smack so that you can break that ceramic magnet. They're very brittle and out of it you end up with pieces of magnets. Those are very, very useful for children to now start doing magnetism, studying magnetism, electric motors and so on. Another source of ceramic magnets, powerful ring magnets is magnetron. This comes from microwave ovens used to produce the microwaves. So if you go down to the store that fixes appliances, ask them for any old magnetrons coming from broken microwave ovens. This is much easier. All you need to do is put a screwdriver in and lever two hinges apart. And off comes the thing. There's another one underneath there, easily accessible as well, you just pull it off. So magnetron is also a source of two lovely, powerful ceramic magnets. And the third source of magnets, and these ones are even more powerful, they are rare earth magnets, neodymium, is an old hard drive from an obsolete, redundant computer. If you go to any place where people take old scrap computers, go and ask them, can you please have the hard drive? They sold these to me for less than a US dollar. It takes a bit of getting into there. There's six little screws that hold it together. If you can get the right tool, you can unscrew that. I've done this a little ahead of time, so it's not quite as easy as I'm making it look now. Or if you can't get screws, use an angle grinder. You can see I've just ground those things off rather brutally. That enables me to take the whole thing off and see the inside. And there is where we find the magnets. Then I've cut through there with an angle grinder, and we lift it up, and there is a very powerful magnet, two powerful magnets under there. This is the powerful little neodymium magnet. How do we get it off there? It's also been bonded. All I do is take a screwdriver and put it on there and give it a hard whack, and that will remove it. Right, well I hope those ideas help you. Certainly you can see magnets are readily available, and there's some fun things that you can do with it. I've shared my ideas with you. If you have any questions, comments or ideas, you can send them in either via the comment on the website, or to me on this email address.