Magnetic bacteria
South pole
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Magnetic bacteria - in Perth, southern hemisphere - have
accumulated close to the south pole of a magnetic bar, at the
edge of a hanging drop. Click on the picture to watch what happens
when the magnetic bar is turned around (AVI-File, 252 kB)
In a classical experiment, the reaction of magnetic bacteria upon turning of a magnetic bar is watched. One could get the impression that the bacteria are attracted or repelled by the magnetic bar. This is, however, not the case. They are swimming actively, as shown on the next page.

At the northern hemisphere, the bacteria accumulate close to the north pole, while bacteria collected in the southern hemisphere move to the south.

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