Champagne bubbles and gravity One of the influences on bubble size is the speed with which a bubble rises in a glass - this, I believe, is due to the force of gravity which acts on the liquid around the CO2. The greater the gravity the faster the bubble moves and so less chance of colliding with other bubbles causing it to grow. If you poured a glass of Champagne on Jupiter, say, the bubbles would be smaller than on Earth since the gravity there is so much higher. Is this true?
 A: The CO$_2$ is solute in the Champagne(/water). The bubbles (created at some condensation nuclei) are in gas phase. Whenever a bubble of gaseous CO$_2$ travels through the solution - strongly depending on the surrounding pressure, temperature,...- the solute CO$_2$ can get gaseous and be "added" to the bubble. But it can also be the other way round: If the pressure is too high, the gas (low density) solutes into the water (where it has higher density) to "save space". That's the water-fizzer principle. 
So your experiment depends mostly on the pressure of the environment - which, in case of Jupiter (gas giant), depend on how far from the center you are.
Jet, no effects of traveling time are taken into account. Without gravity (for simplicity I neglect effects of spatially dependend CO$_2$ concentration and assume it is constant in the glas) your bubble would stay in the same place growing at some rate. When the equilibrium is reached, it comes to a steady state size. 
On the other hand, say, your Champagne glas is very short and the fast bubbles spend to little time in the glass to accumulate a lot of CO$_2$ and don't reach the steady state bubble size. Then gravity plays a more important role. The smaller the gravity, the longer the bubble stays in the glas, hence bubbles have more time to grow.
Finally, the question is complicated and the answer depends (in this idealized model) on the glass height, the environment pressure and the gravity. But your guess is right: Gravity decreases bubble size. The problem is, that on Jupiter pressure depends on gravity, showing an opposite effect to bubble size.
Edit: 
What I previously forgot to think about is thermodynamics. The bubble size is also strongly dependend on the interaction between the CO$_2$ and the Champagne - on surface effects. According to this paper, which considers a system (solvent) and a subsystem (bubble), the work done on the bubble depends on the surface tension $\sigma$. Take a look at eq. 28. So the answer is even more complicated, now depending on the vintage of the Champagne.
