You might recall that grade-school experiment where an iron filing-covered sheet of paper draped over a magnet reveals the invisible lines of its magnetic forces. But with a strong enough magnet (the kind they won’t let you play with in school) and a miniature trampoline, you can actually see those invisible magnetic lines in three dimensions.
The YouTube channel Magnetic Games is full of fun videos involving magnets of all shapes and sizes, but this experiment is particularly fascinating to watch as it plays out in slow motion. When a neodymium magnet, affectionately known as the Death Magnet with a holding power of around 100kg, is dropped onto a makeshift trampoline covered in magnetite, the tiny particles align themselves along the magnet’s invisible lines of force as they’re drawn towards it.
The footage still offers a limited representation of those force lines, just like you saw with that grade school experiment. But had this dropped magnet been filmed with one of those fancy bullet-time camera rigs that made The Matrix’s fight scenes so compelling, we would clearly see those curved magnetic lines wrapping all the way around the magnet as it bounced. Someone get this YouTube channel a bigger budget.