Color Color (American English) or colour (British English; see spelling differences) is the visual perceptual property corresponding in humans to the categories called red, blue, yellow, and others. Color derives from the spectrum of light (distribution of light power versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. Color categories and physical specifications of color are also associated with objects or materials based on their physical properties such as light absorption, reflection, or emission spectra. By defining a color space, colors can be identified numerically by their coordinates. Because perception of color stems from the varying spectral sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantified by the degree to which they stimulate these cells. The science of color is sometimes called chromatics, colorimetry, or simply color science. Physics of color Perception
Physical system Complexity in physical systems[edit] The complexity of a physical system is equal to the probability of it being in a particular state vector. If one considers a classical Newtonian ball situation with a number of perfectly moving physical bodies bouncing off the walls of a container, the system-state probability does not change over time. The entropy of the system changes over time, but the probability of the state vector does not change. One can periodically evaluate the complexity of this system, and the complexity of this system does not change. In a physical system, a lower probability state vector is equivalent to a higher complexity. In mathematical systems, one can consider the complexity of particular states more easily. See also[edit] References[edit] Jump up ^ An Essay on the Investigation of the First Principles of Nature. External links[edit]
Covariant formulation of classical electromagnetism The covariant formulation of classical electromagnetism refers to ways of writing the laws of classical electromagnetism (in particular, Maxwell's equations and the Lorentz force) in a form that is manifestly invariant under Lorentz transformations, in the formalism of special relativity using rectilinear inertial coordinate systems. These expressions both make it simple to prove that the laws of classical electromagnetism take the same form in any inertial coordinate system, and also provide a way to translate the fields and forces from one frame to another. However, this is not as general as Maxwell's equations in curved spacetime or non-rectilinear coordinate systems. This article uses SI units for the purely spatial components of tensors (including vectors), the classical treatment of tensors and the Einstein summation convention throughout, and the Minkowski metric has the form diag (+1, −1, −1, −1). Covariant objects[edit] Preliminary 4-vectors[edit] In meter−1 the four-gradient is
Geometrical optics The simplifying assumptions of geometrical optics include that light rays: propagate in rectilinear paths as they travel in a homogeneous mediumbend, and in particular circumstances may split in two, at the interface between two dissimilar mediafollow curved paths in a medium in which the refractive index changesmay be absorbed or reflected. Explanation[edit] A slightly more rigorous definition of a light ray follows from Fermat's principle, which states that the path taken between two points by a ray of light is the path that can be traversed in the least time.[1] Reflection[edit] Glossy surfaces such as mirrors reflect light in a simple, predictable way. With such surfaces, the direction of the reflected ray is determined by the angle the incident ray makes with the surface normal, a line perpendicular to the surface at the point where the ray hits. Refraction[edit] Illustration of Snell's Law and another medium with index of refraction . where and ) and object distance ( varies slowly. . with
Visual appearance Appearance of reflective objects[edit] The appearance of reflecting objects is determined by the way the surface reflects incident light. The reflective properties of the surface can be characterized by a closer look at the (micro)-topography of that surface. Definition diffusion, scattering: process by which the spatial distribution of a beam of radiation is changed in many directions when it is deviated by a surface or by a medium, without change of frequency of its monochromatic components.[1] Basic types of light reflection[edit] Appearance of transmissive objects[edit] Terminology[edit] Reflective objects [2] Transmissive objects [4] See also[edit] References[edit] Jump up ^ CIE No17.4-1987: International lighting vocabulary, 4th ed. F. External links[edit] Instrumentation for measurement and evaluation of appearance characteristics is available from:
Observation Observation is the active acquisition of information from a primary source. In living beings, observation employs the senses. In science, observation can also involve the recording of data via the use of instruments. The term may also refer to any data collected during the scientific activity. Observation in science[edit] The scientific method requires observations of nature to formulate and test hypotheses.[1] It consists of these steps:[2][3] Asking a question about a natural phenomenonMaking observations of the phenomenonHypothesizing an explanation for the phenomenonPredicting a logical consequence of the hypothesisTesting the hypothesis by an experiment, an observational study, or a field studyCreating a conclusion with data gathered in the experiment, or forming a revised/new hypothesis and repeating the process Senses are limited, and are subject to errors in perception such as optical illusions. Observational paradoxes[edit] Biases[edit] Confirmation bias[edit] Processing bias[edit]
Quantum mechanics Description of physical properties at the atomic and subatomic scale Quantum mechanics is a fundamental theory in physics that describes the behavior of nature at and below the scale of atoms.[2]: 1.1 It is the foundation of all quantum physics including quantum chemistry, quantum field theory, quantum technology, and quantum information science. Classical physics, the collection of theories that existed before the advent of quantum mechanics, describes many aspects of nature at an ordinary (macroscopic) scale, but is not sufficient for describing them at small (atomic and subatomic) scales. Quantum mechanics arose gradually from theories to explain observations that could not be reconciled with classical physics, such as Max Planck's solution in 1900 to the black-body radiation problem, and the correspondence between energy and frequency in Albert Einstein's 1905 paper, which explained the photoelectric effect. Overview and fundamental concepts Mathematical formulation . and , where Here .
Óptica geométrica Formación de un arco iris por medio de la óptica geométrica. La óptica geométrica usa la noción de rayo luminoso; es una aproximación del comportamiento que corresponde a las ondas electromagnéticas (la luz) cuando los objetos involucrados son de tamaño mucho mayor que la longitud de onda usada; ello permite despreciar los efectos derivados de la difracción, comportamiento ligado a la naturaleza ondulatoria de la luz. Esta aproximación es llamada de la Eikonal y permite derivar la óptica geométrica a partir de algunas de las ecuaciones de Maxwell. Propagación de la luz[editar] Reflexión y refracción[editar] El fenómeno más sencillo de esta teoría es la de la reflexión, si pensamos unos minutos en los rayos luminosos que chocan mecánicamente contra una superficie que puede reflejarse. La segunda ley de la reflexión nos indica que el rayo incidente, el rayo reflejado y la normal con respecto a la superficie reflejada están en el mismo plano.[2] Ley de Snell[editar] Lentes[editar] Espejos[editar]
Theory of Constraints The theory of constraints (TOC) is a management paradigm that views any manageable system as being limited in achieving more of its goals by a very small number of constraints. There is always at least one constraint, and TOC uses a focusing process to identify the constraint and restructure the rest of the organization around it. TOC adopts the common idiom "a chain is no stronger than its weakest link." This means that processes, organizations, etc., are vulnerable because the weakest person or part can always damage or break them or at least adversely affect the outcome. History[edit] An earlier propagator of the concept was Wolfgang Mewes[2] in Germany with publications on power-oriented management theory (Machtorientierte Führungstheorie, 1963) and following with his Energo-Kybernetic System (EKS, 1971), later renamed Engpasskonzentrierte Strategie as a more advanced theory of bottlenecks. Key assumption[edit] The five focusing steps[edit] Constraints[edit] Breaking a constraint[edit]