Hi Ufo,
I found some additional references to support my (and Ernst's) view on the film.
This green magnetic viewing film will become lighter or darker when a magnetic field is applied. It turns dark when the field lines are perpendicular the surface, and it turns light when the field lines are horizontal, i.e., across the surface. If a magnet is placed under it, with one of the poles facing the film, it will show the magnet as dark with a light outline.
WONDERMAGNET.COM - NdFeB Magnets, Magnet Wire, Books, Weird Science, Needful Things
WONDERMAGNET.COM - NdFeB Magnets, Magnet Wire, Books, Weird Science, Needful Things
Sometimes also known as Green Magnet Viewing Film, the Film changes colour as a result of interaction with the lines of magnetic field passing through the Magnetic Viewing Film. The Green Magnetic Viewing Film is a thin flexible sheet containing colloidal Nickel flakes suspended in oil as gelatinous microcapsules coated onto the plastic sheet. The nickel flakes, being ferromagnetic, align with the lines of magnetic flux (the magnetic field lines); they can rotate freely because of the gelatinous microcapsules.
Magnetic Viewing Film - e-Magnets UK
Magnetic Viewing Film - e-Magnets UK
The y component or green trace is the perpendicular flux through the film. The graph clearly shows it being zero at .25 inches. Hence the light circle of one half inch diameter on the one half inch diameter magnet. The rest of the film is dark because there is perpendicular flux shown by the non-zero values of y.
I took the image of the viewing film from Ben's post #208 video at 8:25 min. BTW, I disagree with the fellow in the video when he claims the light circle on the viewing film is caused by edge currents in the magnet.
Originally posted by bistander
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bi




The condescending upper strata admit

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