Falling Stout Bubbles Explained

http://www.bbc.co.uk/news/science-environment-18247680

With graduation approaching, I thought it might be appropraite to look at the science behind one of the beverages that will be around. Stout beers such as Guinness have always had the mysterious property of its bubbles sinking to the bottom of a glass. Lately though, it has been thought that the reason the bubbles in stout beers sink to the bottom of the glass rather than rise to the top is due to the shape of the glass they are served in and the way it relates to the density of bubbles and the surrounding liquid. Imagine a standard pint glass. Because of its slope, the bubbles move away from the wall so a more dense region of fluid is created near the wall. This dense region of fluid sinks, pulling the bubbles in solution down with it. The bubbles are not actually sinking then, the force exerted on them by the dense fluid forces them to fall to the bottom of the glass.

This is perfect because of grad, I will for sure think of this while drinking one and make sure to tell everyone around, so I seem almost as intelligent as Clinty!