Scientific law

Debye's law.

A scientific law is a scientific proposition that asserts a constant relationship between two or more variables or factors, each of which represents a property or measurement of concrete systems. It is also defined as a constant and invariable rule and norm of things, arising from their first cause or from their qualities and conditions. It is usually expressed mathematically or in formalized language. Very general laws can have an indirect proof by verifying particular propositions derived from them and that are verifiable. Inaccessible phenomena receive indirect proof of their behavior through the effect they can produce on other facts that are observable or experienceable.

In the architecture of science, the formulation of a law is a fundamental step. It is the first scientific formulation as such. In the law the ideal of scientific description is realized; the entire building of scientific knowledge is consolidated: from observation to theoretical hypothesis-formulation-observation-experiment (scientific law), general theory, to the system. The system of science is or tends to be, in its most solid content, a system of laws.

Different dimensions that are contained in the concept of law:

• The merely descriptive apprehension
• Logic-tomatic analysis
• Ontological detention

From a descriptive point of view, the law is shown simply as a fixed relationship, between certain phenomenal data. In logical terms, it supposes a type of proposition, as an affirmation that links various concepts related to phenomena as truth. As for the ontological consideration, the law as a proposition has historically been interpreted as a representation of the essence, properties or accidents of a substance. Today it is understood that this ontological situation focuses on fixing the constants of natural events, on the apprehension of the regularities perceived as a phenomenon and incorporated into a way of "seeing and explaining the world".

The epistemological problem consists in considering the law as truth and its formulation as language and in establishing its «connection with reality», where two aspects must be considered:

• The term of the real to which the law is intentionally directed or referred, i.e. the constancy of the phenomena in their occurrence as the object of knowledge. Generally, and in a vulgar way, it is usually interpreted as "cause/effect relationship" or "description of a phenomenon". It is formulated logically as a hypothetical proposition in the form: a, b, c. under conditions, h, i, j... will occur s, y, z...
• The form and procedure in which the law is constituted, that is, the problem of induction.

Description

General laws can be demonstrated by indirect proofs by checking verifiable particular propositions derived from them. Inaccessible phenomena are subjected to indirect tests through qualitative and quantitative assessment of the evolution of the effect they generate on other observable and experimental facts.

• In natural sciences a scientific law is a rule in which joint, generally causal, occurrence events are related, and has been manifested by the scientific method. It is accepted that after a natural scientific law there is a certain mechanism necessary to make the facts happen on a regular basis.
• In social sciences a confirmed scientific hypothesis refers to a characteristic common to many different social phenomena, of regular or constant pattern over time in certain circumstances. It is said that social subjects behave under the same characteristics, that is, according to the law of behavior. Some social laws are sometimes considered to be contingent or historically conditioned.

Popper, in a falsificationist conception of scientific rationality, stated that "every natural law can be expressed with the statement that such and such a thing cannot occur".

Scientific law and science

Facts that evolve according to regular and constant patterns in science are described by a linguistic proposition or scientific law, which is a statement of the facts in all their complexity. With experimental science begins the investigation of scientific laws linked to different phenomena. Galileo Galilei (1564-1642) wrote:

If it is true that an effect is the consequence of a single primary cause and that between the cause and the effect there is a firm and constant link, it must be concluded, necessarily, that where a firm and constant alteration is perceived in the effect, there will be a firm and constant alteration in the cause.

Galileo Galilei^{[chuckles]required]}

The mathematician-physicist Henri Poincaré (1858-1912) gave a similar definition:

What is a law? It is a constant link between an antecedent and a consequent, between the present state of the world and its immediate later state.

Poincaré^{[chuckles]required]}

Scientific activity is carried out according to scientific law. Hence, the physicist Max Planck has proposed^{[citation needed]} the following principles of experimental science:

• Nature exists by itself, and man is but a small part of it
• Nature is legal (satisface laws) and legality is causal (there is no objective chance)
• Reality can be known gradually, though never perfectly
• Science marches from diversity to unity, from subjective to objective, and from absolute

Currently it is known that there are both causal and probabilistic or stochastic scientific laws. Hence, in the concept of scientific law, both types of law (deterministic and stochastic) must be considered. One could expand the foundations of Planck's science and propose the following (tacitly accepted by most scientists):^{[citation required]}

• Everything that exists is governed by natural laws
• These laws are invariant in time and space
• The activity of the scientist is to describe them
• The existence of these laws is independent of human being describing them or not
• It is possible, in principle, to know all the laws

Examples of Scientific Laws

Newton's Laws

This section is an extract from Newton Laws.[chuckles]edit]

Newton's first and second law, in Latin, in the original edition of his work Mathematica Principia

Newton's laws, also known as laws of the Newton movement, are three principles from which a large part of the problems posed in classical mechanics, in particular those related to the movement of the bodies, which revolutionized the basic concepts of the physics and movement of the bodies in the universe.

They constitute the foundations not only of classical dynamics but also of classical physics in general. Although they include certain definitions and in a sense can be seen as axioms, Newton said they were based on quantitative observations and experiments; they can certainly not be derived from other more basic relationships. The proof of its validity lies in its predictions... The validity of these predictions was verified in every case for more than two centuries.

In particular, the relevance of these laws lies in two aspects: on the one hand they constitute, together with the transformation of Galileo, the bases of classical mechanics, and on the other, by combining these laws with the law of universal gravitation, they can deduce and explain Kepler's laws on the planetary movement. Thus, Newton's laws allow to explain, for example, both the movement of the stars and the movements of the artificial projectiles created by the human being and all the mechanics of operation of the machines. His mathematical formulation was published by Isaac Newton in 1687 in his work Philosophiæ naturalis principia mathematica.

Newton's dynamics, also known as classical dynamics, are only met in the inertial reference systems (which move at constant speed; the Earth, although it turns and prays, is treated as such for the purposes of many practical experiments). It is only applicable to bodies whose speed differs considerably from the speed of light; when the speed of the body is approaching 300 000 km/s (which would occur in non-inercial reference systems) there are a number of phenomena called relativistic effects. The study of these effects (contraction of length, for example) corresponds to the theory of special relativity, enunciated by Albert Einstein in 1905.

Mendel's Laws

This section is an extract of Mendel Laws.[chuckles]edit]

Mendelian monohybrid crossing

Mendel's laws (as a whole known as Mendelian genetics) are the set of basic rules on the transmission by genetic inheritance of the characteristics of parent organisms to their offspring. They constitute the foundation of genetics. The laws are derived from work on crosses between plants by Gregor Mendel, an Austrian Augustinian monk, published in 1865 and in 1866, although he was long ignored until his rediscovery in 1900.

The history of science finds in the Mendelian heritage a milestone in the evolution of biology, only comparable to Newton's laws in the development of physics. Such an assessment is based on that Mendel was the first to formulate with complete precision a new theory of inheritance, expressed in what would be called "Mendel Laws", which faced the little rigorous theory of inheritance, by blood mixture. This theory contributed to biological studies the basic notions of modern genetics.

However, it was not only his theoretical work that gave Mendel his scientific scope; no less remarkable have been the epistemological and methodological aspects of his research. The recognition of the importance of rigorous and systematic experimentation and the expression of observational results in a quantitative way through the use of statistics revealed a new epistemological stance for biology. Therefore, Mendel is often conceived as the paradigm of the scientist who, from the meticulous observation free of prejudice, manages to infer his laws inductively, which would constitute the foundations of genetics. In this way Mendel's work has been integrated into the teaching of biology: in the texts, the Mendelian theory appears constituted by the famous three laws, conceived as inductive generalizations from the data collected from the experimentation.

Conservation Laws