What Is Life? information has to be both small in size and permanent in time, contradicting the naïve physicist's expectation. This contradiction cannot be resolved by classical physics. In chapter IV, Schrödinger presents molecules, which are indeed stable even if they consist of only a few atoms, as the solution. Even though molecules were known before, their stability could not be explained by classical physics, but is due to the discrete nature of quantum mechanics. Furthermore, mutations are directly linked to quantum leaps. He continues to explain, in chapter V, that true solids, which are also permanent, are crystals. The stability of molecules
Atomic, molecular, and optical physics system of electrons and an atomic nucleus, while molecular physics is the study of the physical properties of molecules. The term "atomic physics" is often associated with nuclear power and nuclear bombs, due to the synonymous use of "atomic" and "nuclear" in standard English. However, physicists distinguish between atomic physics — which deals with the atom as a system consisting of a nucleus and electrons — and nuclear physics, which considers atomic nuclei alone. The important experimental techniques are the various types of spectroscopy. Molecular physics, while closely related to atomic physics, also overlaps greatly with theoretical chemistry, physical chemistry