Horizons in World Physics : Volume 307

This volume contains six chapters which describe recent advancements in physics. Chapter One discusses optical thermometry when Eu3+ ions are substituted in various perovskites/double perovskite lattices. Chapter Two deals with various aspects of measurements of cosmic-ray interactions on the Earths surface. Chapter Three covers the use of machine learning for revealing the transfer of xylene from the ambient air to rainwater and an explainable artificial intelligence framework for investigating the relevance of the monitored parameters and identification of the key factors that govern wet deposition of xylene. Chapter Four proposes a new universal constant that connects events in the micro- and macro-world as a consequence of neutrino processes of proton clustering. Chapter Five introduces a new proposal for a gravitational Bose Einstein condensate associated with a special relativity deformed by a minimum speed. Lastly, Chapter Six studies the possible effect of proper ultralight massive structures on the propagation behaviour of gravitational waves and neutrinos.