physicsfun on Instagram: "Magnetic Viewing Films: making the invisible visible with four versions of magnetic viewing film. 1) the classic green Magneview film from the 1990s with tiny bubble cavities filled with oil and flakes of nickel, 2) silver high-definition film with smaller cavities, 3) golden high definition film with reflective crystals of some kind in the tiny capsules, and 4) the most recent invention featuring capsules filled with suspended magnetic nanoparticles producing different