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Science Questions

This is going to be a new segment, hopefully daily. But daily is a kind of iffy thing with me. Heh. But anyway, pretty much I'll answer a random science question. I'll answer one that someone’s emailed me (mookie -at- mookieriffic.mu.nu) or I'll grab one of my "Handy Answer Science Books" and pick a random page and question. If its an Emailed question, you might want to take the answer with a grain of salt. But with out further ado:

Crystal wine glasses can shatter when resonating, but can they make music?
If the energy of a resonant standing wave is large enough, a crystal wineglass can shatter quite easily, but when the amplitude is smaller, the wineglass can produce a sound instead. Take, for example, a person rubbing his finger around the moist lip of a crystal wineglass. The glass seems to sing or hum. The humming is caused by the work the finger does on the glass: the rubbing of the glass causes it to achieve a standing wave pattern and perhaps resonate. The resonating molecules in the glass generate enough energy to vibrate the surrounding air and create a steady humming sound.

The frequency of the sound can be adjusted the same way that the frequency in an organ pipe can be adjusted--by changing the height of the air column, or in the case of the wine glass, by adding to taking away some of the liquid inside the glass.


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oooooo... You have a preference for a field of science?... lol... I'll try not to make the question to mind bending... This is supposed to be fun right...


Ever see/hear a Glass Harmonica? Neither have I, but have seen pictures, seem to remember having heard recordings. It was invented by Benjamin Franklin. It was a horizontal axle stuck co-axially through a succession of glass bowls, each bowl slightly bigger/smaller than its neighbor. It looked vaguely like an interrupted cone. The whole thing sat in a trough of water, and had a treadle and crank to spin the axle. You played it by touching your fingers to the wet, spinning rims of the bowls. I think Mozart even wrote a piece for it. Its use was discouraged to the point of suppression because the sound got on a lot of people's nerves really badly.


On what planet could you stand, looking in one direction, see the back of your head (not possible to go there and do this, of course) but read it in a mindbending book many years ago and can now not find the answer. It has to have something to do with light bending and/or density of planet's atmosphere.
Anyone know? Please help!