Preface

Following the success of PNCS16 in Canterbury, UK, in 2022, we are delighted to have organized the 17th International Conference on the Physics of Non-Crystalline Solids (PNCS17) that took place in Tsukuba, Japan, between 10 and 13 August 2025.Since the inaugural conference at Alfred University in 1958, this event has served as an international platform for discussing the latest advancements in the field of non-crystalline solid materials physics.This is the second time the conference was held in Japan, the first occasion being in 1987 (when PNCS6 was organized by Prof. S. Sakka in Kyoto).Glass is an important class of materials in our daily lives, and understanding their fundamental properties is one of the great unsolved problems in physics.The conference hosted many glass scientists from industrial and academic institutes alike.The main topics covered were glass transition, relaxation in glasses, structureproperty relationships, and glasses and liquids under high pressure and temperature.Functional materials, measurement techniques, and theoretical and mathematical approaches have also been in the focus.In addition to the plenary session and Zachariasen award lecture, sponsored by the Journal of Non-Crystalline Solids, two special and 11 conventional sessions were held.Over 200 participants from 18 countries gathered in Tsukuba to engage in in-depth discussions during the sessions.We are confident that the conference was a resounding success, with participants enjoying both the conference and the opportunity to experience Japanese culture and cuisine.The next conference is set to take place in Brazil in 2028.This special issue contains thirteen articles (one of which will be published in May issue), describing the physics of non-crystalline solids and related materials.We believe that this special issue will pave the way for new breakthroughs in the field of non-crystalline materials science.