What would happen if you open a bottle of fizzy drink in a weightless environment? On Earth, pouring a fizzy drink into a glass or opening a bottle, you see the gas start to condense out into bubbles which rise upwards.
You can't pour a Coke into a glass on the ISS but you could (I assume) unscrew a bottle and remove the lid if you're careful.
What would happen in terms of bubbles? And by extension when you see this phenomenon on Earth, why do the bubbles go straight up - due to gravity directly or simply because the lower pressure is (due to gravity) at the top of the bottle?
 A: The liquid would float around in globs, and the bubbles would fizz out indiscriminately from all the surfaces of the globs.
Water molecules are attracted to each other, but the carbon dioxide isn't really attracted to the water. The bubbles would therefore escape from the surface by diffusion, so it would take longer than if there were gravity.
A: The volume of the fizzy drink would increase and squirt out the opening of the bottle. 
Small pockets of gas would be expanding inside the liquid. Normally they'd expand outward and the liquid would stick together and the bubbles would pop out an edge (probably taking some globs of liquid along). But in the bottle all the expansion will just move a liquid with still expanding gas bubbles out the top.
Initially it may not look all that different than an overflowing pop bottle in gravity. 
A: Apparently, according to this guy, the bubbles in the fizzy drink will remain in suspension inside the liquid, as there is no top direction for them to go. Remember in a no gravity environment there is nothing to discriminate between left and right or top and bottom.
Also, NASA has the same thing to say about the matter.
