Magnet hitting trampoline covered with iron filings shows invisible field lines

That dated school experiment with iron filings, a sheet of paper and a bar magnet just got a much-needed upgrade. The YouTube channel Magentic Games just released a wicked new slow-motion video of a magnet falling on a miniature trampoline topped with a thick layer of iron filings. What follows makes for a fascinating watch.

The magnet in the video is a neodymium magnet (known colloquially as the Death Magnet), powerful enough to hold 100 kilograms of weight given the chance. When the magnet hits the makeshift trampoline covered in magnetite, the filings fall into the shape of the death magnet’s invisible magnetic field lines. A sight like this is rare outside of textbooks or a 2D animation at best. Cool as it is to watch, this is just a fraction of all the field lines the magnet has. [caption id=“attachment_6038641” align=“alignnone” width=“1280”] Magnetic field lines of a bar magnet. Image: MIT Physics[/caption] If the whole thing was filmed on a better camera (say, the bullet-time camera rigs from the Matrix’s fight scenes) — there would be plenty more magnetite visible along the magnet’s field lines as it bounces. The good folks over at Magnetic Games know exactly how they work, and have a channel-full of cool magnet-meets-metal visuals for entertainment. As Laughing Squid discovered and points out, their newest video is absolutely incredible.