Ask A Scientist Chemistry Archive

(Created prior to 1993)

Question: What causes the bubbles in a glass of champagne to appear like 
they are coming from the inside bottom of the glass?
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Bubbles in the bubbly are dissolved carbon dioxide gas.  When the 
pressure is lowered (when the bottle is opened) or the liquid heated, the CO2 
is less soluble.  In order for the CO2 to come out of the solution, it needs a 
"seed" (sort of like rain needs a "seed" in a cloud to start falling).  Any 
imperfection in the glass is "seed" enough for the bubbles to form.  Even the 
incredibly small distances between the molecules of the glass can be "seed" if 
the conditions are right.
Joe Schultz
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I seem to recall an article in a 1992 issue of Physics Today by 
Richard Zare and someone else, which discussed this as well as similar 
phenomena in a glass of beer.  All in agreement with Joe's short answer as I 
recall...check it out.
Topper
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