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A physical law or a law of nature is a scientific generalization based on empirical observations. Laws of nature are conclusions drawn from, or hypotheses confirmed by, scientific experiments. The production of a summary description of nature in the form of such laws is the fundamental aim of science. Laws of nature are distinct from legal code and religious Law, and should not be confused with the concept of natural law.1 Description
Several general properties of physical laws have been identified (see Davies (1992) and Feynman (1965)). Physical laws are:
- true. By definition, there have never been repeatable, contradicting observations.
- universal. They appear to apply everywhere in the universe.
- simple. They are typically expressed in terms of a single mathematical equation.
- absolute. Nothing in the universe appears to affect them.
- eternal. Unchanged since first discovered (although they may have been shown to be approximations of more accurate laws—see "Laws as approximations" below), they appear to be unchanged since the beginning of the universe. It is thus presumed that they will remain unchanged in the future.
- omnipotent. Everything in the universe apparently must comply with them.
- "omniscient" (loosely speaking). The behavior of everything in the universe is automatically and immediately "known" to the laws.
- generally conservative of quantity.
- often possessive of symmetry
- typically theoretically reversible in time, although time itself is irreversible
Often, those who understand the mathematics and concepts well enough to understand the essence of the physical laws also feel that they possess an inherent intellectual beauty. Many scientists state that they use their perception of this beauty as a guide in in developing hypotheses, since there seems to be a connection between beauty and truth.
Physical laws are distinguished from scientific theories by their simplicity. Scientific theories have many of the same properties as laws, but are generally more complex than laws; they have many component parts, and are more likely to change as the body of availabe experimental data and analysis develops.
2 Examples
Main article: List of laws in science
See also: scientific laws named after peopleThis is a list of scientific laws named after people. For other lists of eponyms (names derived from people) see Lists of etymologies. Ampere's law Andre-Marie Ampere Avogadro's law Amedeo Avogadro Bernoulli's principle Daniel Bernoulli Boyle's law Robert
Some of the more famous laws of nature are found in Isaac NewtonKneller's portrait of 1689. Sir Isaac Newton ( December 25, 1642 March 20, 1727 by the Julian calendar then in use; or January 4, 1643 March 31, 1727 by the Gregorian calendar) was an English physicist, mathematician, astronomer, philosopher, and alchemis's theories of (now) classical mechanicsClassical mechanics is a model of the physics of forces acting upon bodies. It is often referred to as Newtonian mechanics after Newton and his laws of motion. Classical mechanics is subdivided into statics (which models objects at rest), kinematics (whic, presented in his Principia MathematicaFor Isaac Newton's 1687 book containing basic laws of physics, see Philosophiae Naturalis Principia Mathematica''. The Principia Mathematica is a three-volume work on the foundations of mathematics, written by Bertrand Russell and Alfred North Whitehead a, and Albert EinsteinAlbert Einstein ( March 14 1879 April 18 1955) was a theoretical physicist who is widely regarded as the greatest scientist of the 20th century. He proposed the theory of relativity and also made major contributions to the development of quantum mechanics's theory of relativityAlbert Einstein's theory of relativity is a set of two theories in physics: special relativity and general relativity. The core idea of both theories is that two observers who move relative to each other will often measure different time and space interva. Other examples of laws of nature include Boyle's lawBoyle's law (also known as the Boyle Mariotte law is one of the gas laws, and relates the volume and pressure of an ideal gas held at a constant temperature. The law, expressed in symbols, is: PV k where V is the volume of gas measured in cubic metres or of gases, conservation laws, Ohm's lawOhm's law (named after its discoverer Georg Ohm Ohm's law#References|[1]]]) states that the ratio of the potential difference (or voltage drop) between the ends of a conductor (and resistor) to the current flowing through it is a constant, provided the te, the four laws of thermodynamics, etc.
