Re: Why do the bubbles in soda pop stick to a plastic cup?

Hi Matthew,
This is a very interesting question.  The bubbles come from carbon dioxide 
gas that is dissolved in the soda at the factory where they make it.  It is 
not very happy staying in the liquid, and is looking for a chance to 
escape.  If there is a little bit of dust, or a very small bump on the side 
of the glass, then the gas in the liquid will cling to it and form a 
bubble or string of bubbles.  The other day, I saw a string of bubbles in 
my soda in the middle of the glass, not attached to anything I could see, 
but I knew that there must be a small bit of something in my soda to cause 
the bubbles to start to come out of the liquid.  If you want to prove this 
for yourself, try taking a few grains of sugar and drop them into a glass 
of clear soda.  Bubbles will form around the grains as they fall down the 
glass.  If you really want to get your soda excited, try part of a teaspoon 
of sugar, but I suggest that you do it in the sink!  Have fun, and let me 
know how your experiment goes.

Rick Becker

rbecker@ibadex.com