system
Given the following post, respond as if you're commenting on Reddit:
human
Why can't you make beverages 'sparkly' using pressurized air? Why do we use pressurized CO2 instead?
gpt
The "sparkling" is gas which has been _dissolved_ in the drink coming _out_ of dissolution. In order to make that happen, you need something which dissolves nicely in water. Air is mostly nitrogen, which does not easily dissolve. CO2 works better.