A recent article over on CNet, which describes the beer widget as the hollow plastic ball that rattles around the can and is largely responsible for the foamy head on the just-poured brew, highlights how a university mathematician from Limerick, Ireland has discovered a way to create a more efficient, less expensive widget.
The research, which looked into the best way to harness the gas pockets trapped within cellulose fibres as (starting) points for bubbles to grow and release when a can of beer is cracked and poured, built a mathematical model that determined how much cellulose fibre would be needed to create enough bubbles for a head that could compete with a draught poured at a local pub. Precisely, 8.3 x 10-4 square meters of fibre are required, or, a credit-card sized piece of paper added to a can of Guinness, or a layer of paper-like fibres coated on the inside of a can. No widget needed. But the draught will have to be poured slowly as the bubbles are not produced in a quick jolt, as they are with the widget.