I have found some odd Nucleation points that appear inside of the top area of a bottle of Diet Pepsi (the area right near the cap as shown in pictures below). The nucleation sites appear either as soon as you open the bottle, or after the first drink (I will test this once more and see exactly when it happens and will update this thread). I have only seen this on the 1.25 liter bottles, but have not looked specifically for them on the regular bottles or the 1 liter bottles. I have not tested this with regular Pepsi, but only diet at the moment. Further testing will ensue, and this thread will remain updated. My questions are: what causes these Nucleation sites? Are these put in by the manufacturer (and if so, what purpose do they serve)? What exactly are they (scratches, tiny irregularities, dust, saliva, etc.)? Why do they only appear near the top, while the rest of the bottle does not have them(as shown below)? Are they even nucleation sites (I assume they are because of the way the diet Pepsi is able to stick to them, and the way they cause the diet Pepsi to release small amounts of carbon), or am I misinterpreting what I am seeing? Any and all answers would be helpful.