This question came to us when partaking of the bubbly a few weeks ago with my friends. Once we were all in a celebratory state of drunkedness, we noticed something we hadn’t really paid attention to before. In a champagne glass (the talll, narrow kind), why don’t the bubbles rise up fairly evenly from all parts of the champagne like they’re normally depicted in cartoons or drawings? Instead, there seem to be specific places from which strings of bubbles are “emitted”.
i.e. not
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but
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Why is this? My friend theorized that there were tiny particles in the champagne which gathered the CO[sub]2[/sub] onto their surface and it was then released. Could this be the reason?
Your friend is thinking along the right lines. Small particles of dust and the like in the champagne provide nucleation sites. These are areas at which a change of phase/state is energetically favourable, thus it is easier for the CO2 to undissolve at these specific sites.
There are a lot of questions about bubbles in alcoholic beverages beyond this simple nucleation one. There was a welll-known article about the physics of beer bubbles in the October 1991 issue of Physics Today:
That gets me thinking, I wonder if a champagne glass can be manufactured with these microscopic imperfections to create cool, festive patterns from the carbonation?
Certainly, beer glasses with such patterns are very common, in fact in my experience the majority of pint glasses used for lager in UK pubs nowadays have an etched pattern in the base to encourage bubble nucleation and maintain a head. From memory, an eagle pattern is most common.
However, I don’t think the bubbles travel in a straight enough line to preserve a pattern right the way up through the liquid, so I’m not sure a decorative feature would be possible.