Metastable System

A Metastable System is a dynamical system that temporarily resides in an intermediate state of stability, which is not the system’s least energy state, before transitioning to a more stable state.

• AKA: Metastability.
• Context:
  • It can describe systems in physics and chemistry where higher energy states persist temporarily due to energy barriers (e.g., isomers, phase transitions).
  • It can apply to systems with feedback dynamics, such as electronic circuits, neural networks, and decision-making systems, where temporary stable patterns emerge due to external or internal fluctuations (white noise, signal trafficking).
  • It can model behaviors in natural and artificial systems, from subatomic particle configurations to macroscopic ensembles like grain piles or viscous fluids.
  • It can range from simple examples like a bowling pin wobbling before falling to complex phenomena in computational neuroscience involving brain metastability.
  • ...
• Example(s):
  • Bowling Pins, which illustrate mechanical metastability through wobbling and tipping behavior.
  • Isomers, which remain in higher energy configurations until a transition to a lower energy state occurs.
  • Dynamic Systems like electronic circuits and neural networks, where metastability governs temporary signal patterns.
  • Phase Transitions in condensed matter, where metastable states precede structural changes.
  • ...
• Counter-Example(s):
  • Ground States, which represent the state of least energy and are indefinitely stable without external intervention.
  • Steady-State Systems, which do not transition from one state to another but remain constant over time.
  • Chaotic Systems, which lack the temporary stability characteristic of metastable systems.
• See: White Noise, Chemistry, Physics, Energy Level, Dynamical System, Ground State, Bowling Pin, Isomer, Potential Energy, Phase Transition#Modern Classifications, Subatomic Particle, Atom.

---

---

---

---

References

2024

• (Wikipedia, 2024) ⇒ https://en.wikipedia.org/wiki/metastability Retrieved:2024-12-21.
  • In chemistry and physics, metastability is an intermediate energetic state within a dynamical system other than the system's state of least energy.

    A ball resting in a hollow on a slope is a simple example of metastability. If the ball is only slightly pushed, it will settle back into its hollow, but a stronger push may start the ball rolling down the slope. Bowling pins show similar metastability by either merely wobbling for a moment or tipping over completely. A common example of metastability in science is isomerisation. Higher energy isomers are long lived because they are prevented from rearranging to their preferred ground state by (possibly large) barriers in the potential energy.

    During a metastable state of finite lifetime, all state-describing parameters reach and hold stationary values. In isolation:

    • the state of least energy is the only one the system will inhabit for an indefinite length of time, until more external energy is added to the system (unique "absolutely stable" state);
    • the system will spontaneously leave any other state (of higher energy) to eventually return (after a sequence of transitions) to the least energetic state.
  • The metastability concept originated in the physics of first-order phase transitions. It then acquired new meaning in the study of aggregated subatomic particles (in atomic nuclei or in atoms) or in molecules, macromolecules or clusters of atoms and molecules. Later, it was borrowed for the study of decision-making and information transmission systems.

    Metastability is common in physics and chemistry – from an atom (many-body assembly) to statistical ensembles of molecules (viscous fluids, amorphous solids, liquid crystals, minerals, etc.) at molecular levels or as a whole (see Metastable states of matter and grain piles below). The abundance of states is more prevalent as the systems grow larger and/or if the forces of their mutual interaction are spatially less uniform or more diverse.

    In dynamic systems (with feedback) like electronic circuits, signal trafficking, decisional, neural and immune systems, the time-invariance of the active or reactive patterns with respect to the external influences defines stability and metastability (see brain metastability below). In these systems, the equivalent of thermal fluctuations in molecular systems is the "white noise" that affects signal propagation and the decision-making.

---