The principle of causality (also called the law of cause and effect) is that which relates one process (cause) to another process or state (effect), where the first is partly responsible for the second, and the second is partly dependent on the first. This is one of the main laws of logic and physics. However, recently French and Australian physicists turned off the principle of causality in the optical system they recently created artificially.
In general, any process has many causes that are causal factors for it, and all of them lie in its past. One effect, in turn, can be the cause of many other effects, all of which lie in its future. Causality has a metaphysical connection with the concepts of time and space, and the violation of the principle of causality is considered a serious logical error in almost all modern sciences.
The essence of the concept
Causality is an abstraction that indicates how the world evolves, and is therefore the main concept more prone toto explain the various concepts of progression. It is in some sense connected with the concept of efficiency. In order to understand the principle of causality (especially in philosophy, logic and mathematics), one must have good logical thinking and intuition. This concept is widely represented in logic and linguistics.
Causality in Philosophy
In philosophy, the principle of causality is considered one of the basic principles. Aristotelian philosophy uses the word "cause" to mean "explanation" or the answer to the question "why?", including material, formal, efficient, and ultimate "causes." According to Aristotle, "cause" is also the explanation of everything. The theme of causality remains central to contemporary philosophy.
Relativity and quantum mechanics
In order to understand what the principle of causality says, you need to be familiar with Albert Einstein's theories of relativity and the basics of quantum mechanics. In classical physics, an effect cannot occur before its immediate cause appears. The principle of causality, the principle of truth, the principle of relativity are quite closely related to each other. For example, in Einstein's special theory of relativity, causality means that an effect cannot occur regardless of the cause that is not in the back (past) light cone of the event. Likewise, a cause cannot have an effect outside its (future) light cone. This abstract and lengthy explanation of Einstein, obscure to the reader far from physics, led to the introductionprinciple of causality in quantum mechanics. Either way, Einstein's limitations are consistent with the reasonable belief (or assumption) that causal influences cannot travel faster than the speed of light and/or the passage of time. In quantum field theory, observed events with spacelike dependence must commute, so the order of observations or measurements of observed objects does not affect their properties. Unlike quantum mechanics, the causality principle of classical mechanics has a completely different meaning.
Newton's second law
Causality should not be confused with Newton's second law of conservation of momentum, because this confusion is a consequence of the spatial homogeneity of physical laws.
One of the requirements of the principle of causality, valid at the level of human experience, is that cause and effect must be mediated in space and time (the requirement of contact). This requirement has been very important in the past, primarily in the process of direct observation of causal processes (for example, pushing a cart), and secondly, as a problematic aspect of Newton's theory of gravity (the attraction of the Earth by the Sun through action at a distance), replacing mechanistic proposals such as like Descartes' theory of vortices. The principle of causality is often seen as a stimulus for the development of dynamic field theories (for example, Maxwell's electrodynamics and Einstein's general theory of relativity) that explain the fundamental questions of physics much better thanthe aforementioned theory of Descartes. Continuing the theme of classical physics, we can recall the contribution of Poincaré - the principle of causality in electrodynamics, thanks to his discovery, has become even more relevant.
Empirics and metaphysics
The empiricists' aversion to metaphysical explanations (such as Descartes' theory of vortices) has a strong influence on the idea of the importance of causality. Accordingly, the pretentiousness of this concept has been downplayed (for example, in Newton's Hypotheses). According to Ernst Mach, the concept of force in Newton's second law was "tautological and redundant".
Causality in equations and calculation formulas
The equations simply describe the process of interaction, without any need to interpret one body as the cause of the movement of another and predict the state of the system after this movement is completed. The role of the principle of causality in mathematical equations is secondary compared to physics.
Deduction and nomology
The possibility of a time-independent view of causality underlies the deductive-nomological (D-N) view of a scientific explanation of an event that can be incorporated into a scientific law. In the representation of the D-N approach, a physical state is said to be explainable if, by applying a (deterministic) law, it can be obtained from given initial conditions. Such initial conditions may include the momenta and the distance from each other of the stars, if we are talking, for example, about astrophysics. This "deterministic explanation" is sometimes called causal.determinism.
Determinism
The downside of the D-N view is that the principle of causality and determinism are more or less identified. Thus, in classical physics, it was assumed that all phenomena were caused by (i.e., determined by) earlier events in accordance with known laws of nature, culminating in Pierre-Simon Laplace's assertion that if the current state of the world were known from accuracy, its future and past states could also be calculated. However, this concept is commonly referred to as Laplace determinism (rather than "Laplace causality") because it depends on determinism in mathematical models - such determinism as is represented, for example, in the mathematical Cauchy problem.
The confusion of causality and determinism is especially acute in quantum mechanics - this science is acausal in the sense that in many cases it cannot identify the causes of actually observed effects or predict the effects of identical causes, but, perhaps, is still determined in some of its interpretations - for example, if the wave function is assumed not to actually collapse, as in the many-worlds interpretation, or if its collapse is due to hidden variables, or simply redefines determinism as a value that determines probabilities rather than specific effects.
Difficult about the complex: causality, determinism and the principle of causality in quantum mechanics
In modern physics, the concept of causality is still not fully understood. Understandingspecial relativity confirmed the assumption of causality, but they made the meaning of the word "simultaneous" dependent on the observer (in the sense in which the observer is understood in quantum mechanics). Therefore, the relativistic principle of causality says that the cause must precede the action according to all inertial observers. This is equivalent to saying that a cause and its effect are separated by a time interval, and that the effect belongs to the future of the cause. If the time interval separates two events, this means that a signal can be sent between them at a speed not exceeding the speed of light. On the other hand, if the signals can travel faster than the speed of light, this would violate causality because it would allow the signal to be sent at intermediate intervals, which means that, to at least some inertial observers, the signal would appear to be moving backwards in time. For this reason, special relativity does not allow different objects to communicate with each other faster than the speed of light.
General Relativity
In general relativity, the principle of causality is generalized in the simplest way: an effect must belong to the future light cone of its cause, even if spacetime is curved. New subtleties must be taken into account in the study of causality in quantum mechanics and, in particular, in relativistic quantum field theory. In quantum field theory, causality is closely related to the principle of locality. However, the principlelocality in it is contested, since it is highly dependent on the interpretation of the chosen quantum mechanics, especially for quantum entanglement experiments that satisfy Bell's theorem.
Conclusion
Despite these subtleties, causality remains an important and valid concept in physical theories. For example, the notion that events can be ordered into causes and effects is necessary to prevent (or at least understand) paradoxes of causality such as the "grandfather paradox" which asks: "What happens if a traveler time to kill his grandfather before he ever meets his grandmother?"
Butterfly effect
Theories in physics, such as the butterfly effect from chaos theory, open up possibilities like distributed systems of parameters in causality.
A related way of interpreting the butterfly effect is to see it as indicating the difference between the application of the notion of causality in physics and the more general use of causality. In classical (Newtonian) physics, in the general case, only those conditions that are necessary and sufficient for the occurrence of an event are (explicitly) taken into account. Violation of the principle of causality is also a violation of the laws of classical physics. Today, this is only permissible in marginal theories.
The principle of causality implies a trigger that starts the movement of an object. In the same way, a butterfly canregarded as the cause of the tornado in the classic example explaining the theory of the butterfly effect.
Causality and quantum gravity
Causal Dynamic Triangulation (abbreviated as CDT), invented by Renata Loll, Jan Ambjörn and Jerzy Jurkiewicz and popularized by Fotini Markopulo and Lee Smolin, is an approach to quantum gravity that, like loop quantum gravity, is background independent. This means that he does not assume any pre-existing arena (dimensional space), but attempts to show how the structure of space-time itself gradually evolves. The Loops '05 conference, hosted by many loop quantum gravity theorists, included several presentations that discussed CDT at a professional level. This conference generated considerable interest from the scientific community.
On a large scale, this theory recreates the familiar 4-dimensional space-time, but shows that space-time must be two-dimensional on the Planck scale and show fractal structure on slices of constant time. Using a structure called a simplex, it divides space-time into tiny triangular sections. A simplex is a generalized form of a triangle in different dimensions. A three-dimensional simplex is usually called a tetrahedron, while a four-dimensional one is the main building block in this theory, also known as a pentatope or pentachoron. Each simplex is geometrically flat, but the simplexes can be "glued" together in a variety of ways to create curved spaces. In cases where previousattempts to triangulate quantum spaces produced mixed universes with too many dimensions, or minimal universes with too few, CDT avoids this problem by only allowing configurations where the cause precedes any effect. In other words, the time frames of all connected edges of simplices, according to the CDT concept, must coincide with each other. Thus, perhaps causality underlies the geometry of space-time.
Theory of cause and effect relationships
In the theory of cause-and-effect relationships, causality occupies an even more prominent place. The basis of this approach to quantum gravity is the theorem of David Malament. This theorem states that the causal spacetime structure is sufficient to restore its conformal class. Therefore, to know the conformal factor and the causal structure is enough to know the space-time. Based on this, Raphael Sorkin proposed the idea of causal connections, which is a fundamentally discrete approach to quantum gravity. The causal structure of space-time is represented as a primordial point, and the conformal factor can be established by identifying each element of this primordial point with unit volume.
What the principle of causality says in management
For quality control in manufacturing, in the 1960s, Kaworu Ishikawa developed a cause-and-effect diagram known as the "Ishikawa diagram" or "fish oil diagram". The diagram categorizes all possible causes into six maincategories that directly displays. These categories are then subdivided into smaller subcategories. The Ishikawa method identifies the "causes" of pressure on each other by various groups involved in the production process of a firm, company or corporation. These groups can then be labeled as categories on the charts. The use of these diagrams now goes beyond product quality control, and they are used in other areas of management, as well as in the field of engineering and construction. Ishikawa's schemes have been criticized for failing to distinguish between necessary and sufficient conditions for conflict to arise between the groups involved in production. But it seems that Ishikawa didn't even think about these differences.
Determinism as a worldview
The deterministic worldview believes that the history of the universe can be exhaustively represented as a progression of events, representing a continuous chain of causes and effects. Radical determinists, for example, are sure that there is no such thing as "free will", since everything in this world, in their opinion, is subject to the principle of correspondence and causality.
