Structure, scale and emergence

Area of Science:

• Chemistry
• Physics
• Materials Science

Background:

• Chemists and physicists attribute structures at the molecular scale to substances and materials.
• Understanding these structures and their relation to other scales is crucial.

Purpose of the Study:

• To define molecular structure as a set of preserved properties and relations.
• To argue that molecular structures and the substances they define are emergent phenomena.
• To explore the scale-dependent nature of structures, substances, and their composition.

Main Methods:

• Conceptual analysis of molecular structure.
• Argumentation based on the definition of structure as abstraction.
• Use of concrete examples to illustrate scale-dependence.

Main Results:

• Structure is defined as abstraction: properties and relations preserved across all conditions of existence.
• Molecular structures and substances are emergent.
• Structures are scale-dependent, existing only within specific physical conditions.
• Substance and structure distinctness is scale-dependent.
• Compositional requirements for substances and molecular species are scale-dependent.

Conclusions:

• Molecular structure is an emergent, scale-dependent concept.
• Understanding molecular composition requires considering environment and lifetime, not solely energy.
• The framework provides a new perspective on the nature of chemical substances and materials.