They're pretty amazing to play with. For example, you can make a small one hop around in your hand by turning over another one relatively far away. Much more dramatic experiences than you get playing around with refrigerator magnets.
The safety warnings there are serious -- depending on the size, these magnets will be pulled toward each other with tens to hundreds of pounds of force, and they don't care what's in the way. Even the medium-sized ones that I got drew blood when they pinched me.
(As with other magnets, the ones that are small enough to be swallowed would also be a severe hazard if a child swallowed them, although most on that page are much too big to swallow. On the other hand, if you let some of the larger disc-shaped ones loose from far enough apart, they'll fly together with enough force to shatter!)
I managed to build a 0.9T Hall effect measurement system with two 1.5 inch diameter N52 magnets.
The scariest part was successfully assembling the magnets into the yoke. If we made a mistake, could easily use a finger, or, if they touch, we'd have to scrap everything and buy more to try again because you couldn't pull them apart.
https://unitednuclear.com/index.php?main_page=index&cPath=70...
They're pretty amazing to play with. For example, you can make a small one hop around in your hand by turning over another one relatively far away. Much more dramatic experiences than you get playing around with refrigerator magnets.
The safety warnings there are serious -- depending on the size, these magnets will be pulled toward each other with tens to hundreds of pounds of force, and they don't care what's in the way. Even the medium-sized ones that I got drew blood when they pinched me.
(As with other magnets, the ones that are small enough to be swallowed would also be a severe hazard if a child swallowed them, although most on that page are much too big to swallow. On the other hand, if you let some of the larger disc-shaped ones loose from far enough apart, they'll fly together with enough force to shatter!)