S tarting here in the Latin world, a bubble is originally a bulla, that is, a ball; a metallic ball, first, attached to a seal, and by continuity the papal decree stamped with this seal; or a bulla, blown by children from a soapy water, or observed inside a sparkling liquid. Nowadays, bolla designates in Italian both the bubble inside a liquid and the papal seal -in French, we similarly have bulle for both meanings, as in Spanish with bula (where bubbles in liquids are however most often

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... ed by the more modern burbuja). Hence a bubble is first defined by its shape, that is, the pure sphere that we all observed for small gas cavities in Champagne, or for larger spherical bubbles blown by children, the pretext for admirable paintings by Chardin or Manet. Here we describe the negative of this object: as an antibolla in Italian (or antibulle in French [1], and antibula in Spanish) designated the bolla of an antipope (when they existed), an antibubble will be the contrary of a soap bubble, namely, a thin shell of air surrounding water, and immersed in water [2] . We first discuss the way to generate such objects; then, we comment on their (brief) life and their death, comparing them with those of soap bubbles. ᭣ Fig. 1: Submarine photo showing the generation of antibubbles from an impacting jet. The black contour, around each globule, betrays the existence of a film of air. features Article available at