Classical physics In contrast to classical physics, "modern physics" is a slightly looser term which may refer to just quantum physics or to 20th and 21st century physics in general. Modern physics includes quantum theory and relativity, when applicable. A physical system can be described by classical physics when it satisfies conditions such that the laws of classical physics are approximately valid. In practice, physical objects ranging from those larger than atoms and molecules, to objects in the macroscopic and astronomical realm, can be well-described (understood) with classical mechanics. Beginning at the atomic level and lower, the laws of classical physics break
National Laboratory of Atomic, Molecular and Optical Physics spectroscopic databases such as HITRAN. The research of the ion group is focused on trapped molecular ions in the ion traps – relatively new branch of physics. Recent works in this field focus on the production, detection and cooling of the molecular ions. The trapped molecules are subject to spectroscopic investigations and as products/substrates for cold chemistry of single molecules. National Laboratory of Atomic, Molecular and Optical Physics National Laboratory of Atomic, Molecular and Optical Physics (KL FAMO) is the national inter-university research center with the headquarters at Institute of Physics of Nicolaus Copernicus University in Toruń, Poland. Established in