Patterns in a ferrofluid film confined between glass sheets, under water.
Rotating magnet below, static magnet moved by hand from above.
See http://www.electricstuff.co.uk/ferro.html for more info
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https://www.youtube.com/watch?v=b7YFsciXhj8
After the horror that was the crappy PSU http://www.youtube.com/watch?v=T88ej64aXUM
This video looks inside a slightly better made one.
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https://www.youtube.com/watch?v=1F3XlFI1JBo
Followup to pillcam teardown http://www.youtube.com/watch?v=bH6i3bfie_E
A look at patent US2004/0087832 covering methods of deactivating pill cameras and similar devices
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https://www.youtube.com/watch?v=KuercpnVKtI