A lump of magnetic putty totally engulfs a rare-earth magnet in slow motion. The actual sequence is eight times longer than this video shows. The putty will not rest until the magnet is at the center of the glob. What is this "magnetic putty"? From the YouTube link:
The putty looks and feels like regular silly putty, but the difference lies in the fact that it has been infused with millions of micron-sized ferrous particles (most often iron oxide powder). The magnetic putty is not actually magnetic by itself, since the infused particles are made of iron powder.Scott Lawson has other videos about magnetic putty at his YouTube channel.
The presence of the strong neodymium iron boron magnet (the silver cube in the video) magnetizes the ferromagnetic particles in the putty. When this happens, the ferrous particles align with each other and this alignment generates north and south magnetic poles, making the putty into a temporary magnet. Once magnetized, the putty will remain magnetized even after the rare-earth magnet has been removed from the putty. This effect persists for a few hours until thermal agitation shakes the particles and they lose their alignment.
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