Theoretical physics is the development of mathematical formalisms and computational protocols for describing all aspects of objects found in the world around us and their interaction. This can involve ...

Condensed-matter physics is the study of substances in their solid state. This includes the investigation of both crystalline solids in which the atoms are positioned on a repeating three-dimensional ...

Iran is the oldest country with an established government around 3200 BCE. Ancient civilizations of Egypt and China are among the world's oldest. San Marino is the world's oldest continuous republic, ...