Abstract: The mere existence and the spectroscopic behavior of pyramidal molecules like ammonia have remained unsolved problems since the early developments of quantum mechanics. A possible solution can be found on the idea of spontaneous symmetry breaking. I discuss a model proposed some years ago with G. Jona-Lasinio and C. Toninelli and its more recent developments. Despite the simplicity of the model, results are obtained which are in quantitative agreement with experiments and provide predictions for the behavior of general chiral gases and their mixtures in fields from cold atoms to astronomical data. However, many open questions remain including whether this model can be considered a step to understanding homochirality.