Phase transitions are involved in phenomena ranging from the initial stages of the creation of the Universe to the existence of biological objects. It is natural to as whether any phenomena analogous to phase transitions are possible in disordered substances like liquids and glasses. The possibility of such transitions is still very much a matter of debate. Neither the nature nor the features of transformations in liquids and glasses are yet clear, nor is the nature of the order parameters. Investigations in recent years have shown that transformations in liquids and glasses lead to a drastic...