What causes the tiny streams of bubbles in a glass of champagne?
This is a “piffling” question that really did lead to a Nobel prize. Champagne bubbles are filled with carbon dioxide gas, molecules of which get trapped inside tiny cracks or under specks on the inside of the glass. If enough gas accumulates at one of these “nucleation points”, it forms a bubble which grows until it breaks away and floats up to the surface, leaving the nucleation point free for another bubble to form. The result: a constant stream of bubbles apparently rising from nowhere. In 1952, the American physicist Donald Glaser was pondering bubbles rising in his glass of beer when he realised that the same process could reveal the presence of invisible sub-atomic particles, which would leave a trail of bubbles as they zoomed through liquid hydrogen. This led him to invent the “bubble chamber” – and won him the 1960 Nobel Prize for physics. Why is really pure ice blue? Even in ice, molecules of water are constantly vibrating, and these mop up longer, redder wavelengths of light
