TODO can anything interesting and deep be said about "why phase transition happens?" physics.stackexchange.com/questions/29128/what-causes-a-phase-transition on Physics Stack Exchange

The Representative Elementary Volume (REV) is a concept used primarily in the fields of materials science, geophysics, and hydrology. It refers to the smallest volume over which measurements can be taken so that the average properties of the material or medium are representative of the whole sample. The concept is crucial for understanding the macroscopic behavior of heterogeneous materials, such as soils, rocks, and composite materials.

Control loop theory is a framework used in control systems engineering to regulate the behavior of dynamic systems. It involves the use of feedback mechanisms to ensure that a system operates at a desired performance level or set point, even in the presence of disturbances or changes in system parameters. The fundamental components of a control loop typically include: 1. **Process**: The system or process being controlled, which can be anything from a simple mechanical system to a complex process in chemical manufacturing or robotics.

Shear stress is a measure of the intensity of internal forces acting parallel to a surface in a material. It arises when a force is applied tangentially to an area of a material, causing the layers of the material to slide past one another.

Shearing, in physics, refers to a type of deformation that occurs when a force is applied parallel to a surface or plane within a material. This results in the material layers sliding past one another, which alters their shape without necessarily changing their volume. Shearing is a crucial concept in mechanics and materials science, as it helps to explain how materials deform under different types of load.

Mentioned at: en.wikipedia.org/wiki/Phase_transition#Modern_classifications

The more familiar transitions we are familiar with like liquid water into solid water happen at constant temperature.

However, other types of phase transitions we are less familiar in our daily lives happen across a continuum of such "state variables", notably:

Simple shear is a type of deformation that occurs in materials when they are subjected to shear stress. In this mode of deformation, layers of material slide past each other while the overall volume remains constant. It is characterized by the parallel displacement of adjacent layers, which results in an angular distortion of the material. In a simple shear scenario, one side of an object is moved in one direction while the opposite side is held in place or moved in the opposite direction, creating a shear strain.

Soft tissue refers to a group of tissues in the body that connect, support, or surround other structures and organs. Unlike hard tissues, such as bone, soft tissues are more flexible and can be found throughout the body. Soft tissues include: 1. **Muscle Tissue**: This includes skeletal, cardiac, and smooth muscle, which enable movement and function of various organs.

A stream function is a mathematical tool used in fluid mechanics to describe the flow of incompressible fluids. It is a scalar function whose contours represent the flow lines of the fluid. When the flow is two-dimensional, the stream function can help visualize the flow, as the flow velocity components can be obtained from this function. ### Key Characteristics of Stream Functions: 1. **Incompressible Flow**: Stream functions are primarily used for incompressible flow scenarios.

Reaches 2 mK^[ref]. youtu.be/upw9nkjawdy?t=487 from Video "Building a quantum computer with superconducting qubits by Daniel Sank (2019)" mentions that 15 mK are widely available.

Used for example in some times of quantum computers, notably superconducting quantum computers. As mentioned at: youtu.be/uPw9nkJAwDY?t=487, in that case we need to go so low to reduce thermal noise.

The idea tha taking the limit of the non-classical theories for certain parameters (relativity and quantum mechanics) should lead to the classical theory.

It appears that classical limit is only very strict for relativity. For quantum mechanics it is much more hand-wavy thing. See also: Subtle is the Lord by Abraham Pais (1982) page 55.

Stress triaxiality is a measure used to describe the state of stress at a point in a material, particularly in the context of failure and fracture mechanics. It provides insight into how the material will respond under different loading conditions and is particularly useful for analyzing ductile materials.

Thermomagnetic convection refers to the movement of fluid induced by a combination of thermal and magnetic effects, typically in a fluid that exhibits magnetocaloric properties. This phenomenon occurs in materials that can change temperature in response to an applied magnetic field, which in turn can create gradients in temperature and pressure within the fluid, leading to convective motion.

The Timoshenko–Ehrenfest beam theory is an advanced framework for analyzing the behavior of beams that takes into account both bending and shear deformations. This theory improves upon the classical Euler-Bernoulli beam theory, which only considers bending deformations and assumes that cross-sections of the beam remain plane and perpendicular to the beam's axis during deformation.