Petre ROMAN
ABSTRACT :
Complexity springs from the tendency of large-sized dynamic systems – defined as complex structures – of self-organizing in a critical state capable of setting off the avalanche evolutions of extremely different grades. Once in a critical condition, the events studied in biology, climatology or economics, usually separated, become correlated. Systems complexity is manifested through their sensitivity to the modification of the initial conditions of system’s evolution. Even a slight, apparently negligible disruption of theirs may lead to a major irreversible instability, defined by mathematicians as deterministic chaos. Giorgio Parisi, (Nobel Prize winner in Physics, 2022), founder of the complex systems theory, formulated a more general, not only mathematical definition, as follows: ”A system is complex if its behaviour depends essentially on its details. Commonly, this dependence is, in most of the cases, difficult to be understood”. Giorgio Parisi demonstrates the existence of hidden rules which govern the installation of some properties of the complex systems with a highly probable chaotic dynamics. Under critical conditions, the events of numerous sciences (biology, climatology, economics), usually separated, become correlated.