---
title: "Scientific law"
chunk: 5/6
source: "https://en.wikipedia.org/wiki/Scientific_law"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:45:43.771670+00:00"
instance: "kb-cron"
---

In equilibrium, molecules exist in mixture defined by the transformations possible on the timescale of the equilibrium, and are in a ratio defined by the intrinsic energy of the molecules—the lower the intrinsic energy, the more abundant the molecule. Le Chatelier's principle states that the system opposes changes in conditions from equilibrium states, i.e. there is an opposition to change the state of an equilibrium reaction.
Transforming one structure to another requires the input of energy to cross an energy barrier; this can come from the intrinsic energy of the molecules themselves, or from an external source which will generally accelerate transformations.  The higher the energy barrier, the slower the transformation occurs.
There is a hypothetical intermediate, or transition structure, that corresponds to the structure at the top of the energy barrier.  The Hammond–Leffler postulate states that this structure looks most similar to the product or starting material which has intrinsic energy closest to that of the energy barrier.  Stabilizing this hypothetical intermediate through chemical interaction is one way to achieve catalysis.
All chemical processes are reversible (law of microscopic reversibility) although some processes have such an energy bias, they are essentially irreversible.
The reaction rate has the mathematical parameter known as the rate constant. The Arrhenius equation gives the temperature and activation energy dependence of the rate constant, an empirical law.
Thermochemistry:

Dulong–Petit law
Gibbs–Helmholtz equation
Hess's law
Gas laws:

Raoult's law
Henry's law
Chemical transport:

Fick's laws of diffusion
Graham's law
Lamm equation

== Laws of biology ==

=== Ecology ===
Competitive exclusion principle or Gause's law

=== Genetics ===
Mendelian laws (Dominance and Uniformity, segregation of genes, and Independent Assortment)
Hardy–Weinberg principle

=== Natural selection ===
Whether or not Natural Selection is a "law of nature" is controversial among biologists. Henry Byerly, an American philosopher known for his work on evolutionary theory, discussed the problem of interpreting a principle of natural selection as a law.  He suggested a formulation of natural selection as a framework principle that can contribute to a better understanding of evolutionary theory.  His approach was to express relative fitness, the propensity of a genotype to increase in proportionate representation in a competitive environment, as a function of adaptedness (adaptive design) of the organism.

== Laws of Earth sciences ==

=== Geography ===
Arbia's law of geography
Tobler's first law of geography
Tobler's second law of geography

=== Geology ===
Archie's law
Buys Ballot's law
Birch's law
Byerlee's law
Principle of original horizontality
Law of superposition
Principle of lateral continuity
Principle of cross-cutting relationships
Principle of faunal succession
Principle of inclusions and components
Walther's law

== Other fields ==
Some mathematical theorems and axioms are referred to as laws because they provide logical foundation to empirical laws.
Examples of other observed phenomena sometimes described as laws include the Titius–Bode law of planetary positions, Zipf's law of linguistics, and Moore's law of technological growth. Many of these laws fall within the scope of uncomfortable science. Other laws are pragmatic and observational, such as the law of unintended consequences. By analogy, principles in other fields of study are sometimes loosely referred to as "laws". These include Occam's razor as a principle of philosophy and the Pareto principle of economics.

== History ==
The observation and detection of underlying regularities in nature date from prehistoric times – the recognition of cause-and-effect relationships implicitly recognises the existence of laws of nature. The recognition of such regularities as independent scientific laws per se, though, was limited by their entanglement in animism, and by the attribution of many effects that do not have readily obvious causes—such as physical phenomena—to the actions of gods, spirits, supernatural beings, etc. Observation and speculation about nature were intimately bound up with metaphysics and morality.