This GIF Of Magnetic Putty 'Eating' A Piece Of Metal Is Mesmerizing
File this one under "Coolest thing we've seen all day": a cube of magnetic putty swallowing a smaller cube of metal whole.
We first saw this on r/woahdude, a section of Reddit dedicated to "Trippy & mesmerizing games, video, audio & images that make you go 'woah dude!'" Yes, we know they mispelled "whoa."
After digging around a bit, we found the original source: a 1.5-hour time lapse on YouTube made by Scott Lawson.
His description of the video gives some insight into what's going on. Basically, the smaller cube is a super-strong magnet that magnetized the millions of tiny bits of iron oxide in the putty. Once magnetized, the putty tries to distribute itself evenly around the magnet:
"The magnetic putty will eventually arrange itself so that the outer surface is as evenly distributed around the magnet as possible.
Ferromagnetic particles in the putty are strongly attracted to the magnet and very slowly engulf the surface of the magnet. The magnet shown in the picture is a strong neodymium iron boron magnet. It's a very powerful magnet for its size and could erase magnetic stripes found in credit cards and damage electronics!
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.
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."
Here's the original time-lapse video: