As scientists conduct in-depth research, the permeation theory gradually reveals the hidden connections between many seemingly independent systems in our daily lives. The central question of this theory is: when certain connections are formed under random conditions, does this trigger changes in the overall system?
The theory of permeation allows us to understand a simple question - can liquids pass through porous materials?
The theory began in the 1950s when the British Coal Gas Utilization Research Association (BCURA) was investigating the physical properties of coal, particularly its porosity and density. Scientists used permeability models to explore how to understand the phenomenon of fluid flow in the microscopic pores of coal in a stochastic manner. Through the probability of connection, permeation theory has not only found applications in physics, but has also been introduced into other disciplines, including biology, environmental science and other fields.
In short, percolation theory describes these flow behaviors by building a network structure. When a certain critical probability is reached, these networks consisting of small clusters will merge into one or several large clusters. This change was relatively sudden, triggering a qualitative change.
The history of the infiltration movement can be traced back to coal research in the 20th century. Rosalind Franklin's contribution is considered one of the important advances in this regard. Furthermore, many mathematicians and physicists such as Simon Broadbent and John Hammersley established the modern framework of percolation theory after in-depth research.
In these early explorations, scientists asked: In a random environment, does the presence of connections affect how the entire system works?
This question is critical because it reveals unexpected results under certain conditions, which is the essence of the infiltration process. Mathematical modeling of these operations not only improves our understanding of the basic science but also opens up new areas of research.
In infinite lattice networks, we find that the critical probability (pc) cannot be calculated accurately, but its value in some specific cases is certain. For example, in a two-dimensional square grid, pc = 1/2
for bond permeability, a finding that changes scientists' fundamental understanding of network connectivity.
Experiments and simulations have found that when the probability p is less than the critical value, it is difficult to form connected blocks, which means that as the system changes, the connectivity of the network will undergo nonlinear changes. This mutation has wide applications in fields such as biology and social sciences, especially in the study of disease spread models.
The existence of a critical point is like a turning point. When this point is crossed, the behavior of the system will undergo a qualitative change and become completely different.
The expansion of the infiltration theory has also led to the emergence of different models, such as the directed infiltration model and the model that introduces the influence of gravity. These models further simulate a variety of social and natural phenomena, especially in biology and ecology.
For example, ecologists use the infiltration theory to study the impact of environmental fragmentation on ecosystems; epidemiologists use this theory to understand the transmission paths of pathogens. These studies have demonstrated the wide applicability of the infiltration theory.
ConclusionThrough percolation theory, we can not only quantify seemingly random events, but also gain insight into the subtle connections between various systems. In this system, changes in a few key points may lead to drastic changes in the entire system. For future research, we can't help but ask: In more complex networks, are there undiscovered key points that can lead us to rethink the behavior of the system?