Sunday, July 26, 2015

Control light with magnets and olive oil?! (Faraday effect)

See how olive oil and magnets can control the brightness of light via the Faraday effect.
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Measure Verdet constant of olive oil:

Plastic film polarizers:

Faraday effect:


  1. That's intriguing - and also rather beautiful. Thank you.
    Did you test how fast the polarization shift takes effect when the field is established? It looks like you could make a fairly useful modulator at least to a few kHz just by driving coils with large transistors. Regards, Christie Black

    1. Thanks! The effect occurs as quickly as the magnetic field can be established. In this case, it's the inductance of the coil that will limit speed. Even with this large coil, modulating in the KHz should certainly be possible. -Ben

  2. I was really fascinated by the Faraday Effect video you posted. I'm trying to recreate the same experiment and would like to know the specifications of the coil you used. It would be of tremendous help!