[A]

In theoretical physics, quantum field theory (QFT) is a theoretical framework that combines classical field theory, special relativity and quantum mechanics. Quantum field theory emerged from the work of generations of theoretical physicists spanning much of the 20th century. Its development began in the 1920s with the description of interactions between light and electrons, culminating in the first quantum field theory— quantum electrodynamics.

[B]

In most contexts, 'classical field theory' is specifically meant to describe electromagnetism and gravitation, two of the fundamental forces of nature. A physical field can be thought of as the assignment of a physical quantity at each point of space and time. For example, in a weather forecast, the wind velocity during a day over a country is described by assigning a vector to each point in space. Each vector represents the direction of the movement of air at that point, so the set of all wind vectors in an area at a given point in time constitutes a vector field. As the day progresses, the directions in which the vectors point change as the directions of the wind change.

[C]

Lewin's Field Theory proposed that behavior is the result of the individual and the environment. This theory had a major impact on social psychology, supporting the notion that our individual traits and the environment interact to cause behavior. The idea that an individual's behavior, at any time, is manifested only within the coexisting factors of the current "life space" or "psychological field." So a life space is the combination of all the factors that influences a person's behavior at any time.

[D]

Our Retail Concept is located in the Geographic Center of the United States, in Saint Louis. Saint Louis is situated on an ancient geologic structure called the North American Craton, which is the core basement rock forming the North American continent. The area is also well known for its Karst areas, such as Caves, Springs and Sinkholes. The city sits at a confluence of both Human Culture and Physical forces, most notably the Convergence of two of the largest rivers in the World.