has opened the possibility of the immediate measurement and description of configurations of molecules. Roentgen structural analysis through the diffraction of
X-rays, developed by Max von Laue (1879–1960), Sir William Henry Bragg
(1862–1942) and Sir William Lawrence Bragg (1890–1971) has the idea about
the spatial structure of molecule for the first time converted into realistic picture: the
molecules have really a defined configuration of atoms in the space.
However, the relationship between empirical experience and its representation,
in chemistry it is the relationship between chemical formula and measurable
properties of substance, is full of puzzles. As I have already announced, in the
second half of 20th century the new concept, the graph theory has been developed.
The scope of this theory is to find the relation between chemical formula viewed as
a graph, the drawing, with the properties of chemical compounds represented by it
[7, 8]. Chemical formulas are not only the icons, rather they are bearers of
information which should still be discovered.
Chemical graph theory is focused on the problem of chemical formulas. The
triad, contents, language, and script is the foundation of chemical epistemology,
where contents are a real chemical substance and its change, language is chemical
nomenclature, and script are chemical formulas. Formulas as chemical script are not
merely labels for corresponding substances, or for their molecular constitution or
configuration. Pioneers of chemical graph theory, Alexandru Balaban, Frank
Harary, Haruo Hosoya, Ante Graovac, Ivan Gutman, Milan Randić, Nenad
Trinajstić, Harry Wiener, have opened the questions about the metaphysics of
chemical script. As it is represented in following figure, the graph theory is in
principle a sort of meta-representation: while molecular formula is the representation of molecular structure, chemical graph is the representation of molecular
formula, i.e. it is the representation of representation of the structure. Algebraic
matrix of neighbourhood (the numbers show in which neighbourhood relations are
vertices in the graph) is the further metarepresentational step, the
meta-meta-representation of molecular structure. The result of this approach is
surprizing: by the numerical manipulation with meta-meta-representations it is
possible to predict properties of substances merely by looking in their molecular
graphs!
114
11 Models and Reality
X-rays, developed by Max von Laue (1879–1960), Sir William Henry Bragg
(1862–1942) and Sir William Lawrence Bragg (1890–1971) has the idea about
the spatial structure of molecule for the first time converted into realistic picture: the
molecules have really a defined configuration of atoms in the space.
However, the relationship between empirical experience and its representation,
in chemistry it is the relationship between chemical formula and measurable
properties of substance, is full of puzzles. As I have already announced, in the
second half of 20th century the new concept, the graph theory has been developed.
The scope of this theory is to find the relation between chemical formula viewed as
a graph, the drawing, with the properties of chemical compounds represented by it
[7, 8]. Chemical formulas are not only the icons, rather they are bearers of
information which should still be discovered.
Chemical graph theory is focused on the problem of chemical formulas. The
triad, contents, language, and script is the foundation of chemical epistemology,
where contents are a real chemical substance and its change, language is chemical
nomenclature, and script are chemical formulas. Formulas as chemical script are not
merely labels for corresponding substances, or for their molecular constitution or
configuration. Pioneers of chemical graph theory, Alexandru Balaban, Frank
Harary, Haruo Hosoya, Ante Graovac, Ivan Gutman, Milan Randić, Nenad
Trinajstić, Harry Wiener, have opened the questions about the metaphysics of
chemical script. As it is represented in following figure, the graph theory is in
principle a sort of meta-representation: while molecular formula is the representation of molecular structure, chemical graph is the representation of molecular
formula, i.e. it is the representation of representation of the structure. Algebraic
matrix of neighbourhood (the numbers show in which neighbourhood relations are
vertices in the graph) is the further metarepresentational step, the
meta-meta-representation of molecular structure. The result of this approach is
surprizing: by the numerical manipulation with meta-meta-representations it is
possible to predict properties of substances merely by looking in their molecular
graphs!
114
11 Models and Reality