Posted: Sep 17, 2019 6:57 pm
by AlanF
I recently came upon an interesting way to sort of view magnetic fields using a device made with a ferrofluid:

The fluid trapped between the two glass plates generates patterns of light and dark that are clearly related to the magnets' fields. I would like to understand exactly how these patterns are generated.

The ferrofluid contains nano-scale particles of magnetite, so I suspect that these particles are somehow lining up with the magnetic fields and producing some kind of interference, diffraction or Moire patterns. Kind of like how structural color is produced in butterfly wings, certain beetle shells and hummingbird feathers.

Any suggestions?