Today in 1982, US Patent 4322008 A was issued, an invention of Ira Schneider, for his “Drinking Container,” or mug. Here’s the Abstract:

The present invention relates to a drinking container for increasing the number of and ostensibly decreasing the size of bubbles in a drinking liquid having dissolved gases contained therein. The container is provided with a roughened region on its normally smooth interior surface. The roughened region is preferably located at the bottom of the container and may be produced by grinding, sand blasting, acid etching, and the like. It is a feature of the disclosure that the roughened region may be formed of a separate element mechanically locked to the container.