Watch the magic of invisible forces when a magnet bounces on a trampoline

Remember that school-room lesson on invisible forces where the teacher sprinkles iron filings over a sheet of paper that is placed over a magnet? Here's a complete upgrade. Watch these magnetic field patterns in 3D, created when magnetite sand is thrown on magnets – some of them bouncing on a small trampoline – and shot in slow motion. Beautifully captivating.

Via Gizmodo