When you go to a soda fountain and pour some soda into your cup, frothy fizz is generated at the top of the cup. Obviously, it has something to do with carbonation. However, when a cup of soda is just sitting and is not being filled or refilled, there is no fizz.
What causes the fizz? Is the fizz generated by the crashing of the soda into the cup?
I would also like to know how to stop the fizzing produced when the soda cup is being filled/refilled: Can I slow the rate at which the soda falls? Will spinning the liquid on the way down to the cup help attenuate the fizzing? What about changing the material from which the cup is made?