Sorry I was commenting on the scientific explanation - I'm a biologist not a physicist... in fact I don't know any biologists who actually like physics... it's just a necessary evil. Now chemistry however is a different matter...
Prof, we have a glass swan around here that does the same thing. It may be the same thing. The liquid travels up and down the neck. I'll look for it and snap a shot for ya.
i like those metal sculptures with the electromagnets, and you can set them in motion, and they'll stay in motion for a long time (forever?).
my bro has one.