What is a meant by a "Scientific Theory"?

Almost 96% of worlds population and 99.99999% of Pakistan´s population have no
idea what is the correct explantion/meaning of a "Scientific Theory".

Many people learned in elementary school that a theory falls in the middle of a hierarchy of certainty--above a mere hypothesis but below a law. Scientists do not use the terms that way, however. According to the National Academy of Sciences (NAS), a scientific theory is "a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses." No amount of validation changes a theory into a law, which is a descriptive generalization about nature. So when scientists talk about the theory of evolution--or the atomic theory or the theory of relativity, for that matter--they are not expressing reservations about its truth.

In addition to the theory of evolution, meaning the idea of descent with modification, one may also speak of the fact of evolution. The NAS defines a fact as "an observation that has been repeatedly confirmed and for all practical purposes is accepted as 'true.'" The fossil record and abundant other evidence testify that organisms have evolved through time. Although no one observed those transformations, the indirect evidence is clear, unambiguous and compelling.

All sciences frequently rely on indirect evidence. Physicists cannot see subatomic particles directly, for instance, so they verify their existence by watching for telltale tracks that the particles leave in cloud chambers. The absence of direct observation does not make physicists' conclusions less certain. ------------------------------------------------------------------------------------------------------

	Quote:
	Theories which have stood against time

Many theories or technologies have been around for quite a long time. In some cases, it is surprisingly long. (Radio is over 100 years old!) While no guarantee of ultimate correctness, endurance is not something to be ignored either. Below is a list of scientific theories, or technologies, by time period. I've listed technologies with the relevant theory in places.

	Quote:
	Time Periods:

Pre-copernican (1543)
Copernicus through 1800
1800-1900
1900-1950
1950-2000
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Pre-copernican (pre-1543)
Euclidean Geometry
Zero
Algebra
Wheel
Writing
Paper
Fire
Domestication
Agriculture
Plowing
Selective Breeding
Metallurgy/Materials Science
Copper
Bronze
Iron
Pottery
Ceramics
Roads
Ships
Printing
Gunpowder
Clocks
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Copernicus to 1800
Analytic Geometry
Calculus
Statistics
Heliocentric Solar System
Telescope
Newtonian Optics
Conservation of Mass (Lavoisier)
Newton's Law of Gravity
Newton's Laws of Motion
Variational Mechanics
Laplace's Tidal Theory
Celestial Mechanics
Kepler's Laws
Ideal Gas Laws
Vaccination (Jenner, 1xxx)
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1800-1900
Conservation Laws and implications
Navier-Stokes Equations of Fluid Dynamics
First Law of Thermodynamics - Conservation of Energy
Second Law of Thermodynamics
Carnot Cycle
Equivalence of Work and Energy - Joule
Maxwell's Equations for Electromagnetism
Telephone
Radio
Light bulb
Electric motor / Dynamo
Non-euclidean geometry
Photography
The Periodic Table
Atomic theory (many flavors through time, reasonably modern by Dalton)
Stellar Spectroscopy
Radioactivity - Becquerel 1895
Discovery of the Electron 1897
Engines
steam
internal combustion
diesel
external combustion
turbine
Engine-driven transport
Steam ship
Train
Automobile
Ice Ages
Theory for the form of the earth, including isostacy
Principle of superposition (geology)
Germ Theory
Cell Theory
The Theory of Evolution
Mendelian Genetics
Anesthesia
Classical and Operant Conditioning (Pavlov 1897)
Subconsciousness
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Some from before 1950:
Theory of Special Relativity
Theory of General Relativity
Quantum
Mechanics
Electrodynamics
Theory of the Chemical Bond
Semiconductors (and the transistor)
Superconductivity (observed)
Computers
X rays
Nucleosynthesis (what makes the sun shine)
DNA
The Modern Synthesis (of Mendelian genetics and evolution)
Existence of subatomic particles (protons, neutrons, etc)
Existence of Antimatter (positron, ...)
The Big Bang theory
Third Law of Thermodynamics - Nernst
The Norwegian Low (theory from meteorology)
Westward Intensification (why the oceans have strong currents on the western boundaries -- Gulf Stream in Atlantic and Kuroshio in Pacific)
Baroclinic Instability (theory for why storm systems form)
Milankovitch theory of ice ages
Numerical Weather Prediction (Richardson, 1922; Charney, Fjortoft, von Neumann, 1947)
Continental Drift - Wegener, 4th edition 1929
Radioactive Dating
Theory of convection
Theory of flight
Monin-Obukhov theory of convective turbulence
Kolmogoroff theory of isotropic turbulence
Chapman mechanism that explains why the earth has an Ozone Layer (1930)
Inverse theory (using observations to reconstruct unobservable things, like the interior of the earth or of you (seismology and MRI, for example).
Television
Theory for the geostationary satellite - Arthur C. Clarke
A bomb
Nuclear power plants
Zernike's phase contrast
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...And some recent ones (since 1950)
Quantum Chromodynamics
Existence of Subnuclear particles (quarks)
Unification of the Electromagnetic and Weak Nuclear Force
High Temperature Superconductivity
Superconductivity -- BCS theory (1957)
Lasers
Chaos (can split between here and the previous period, depending on your definitions)
Theory of Radiative Transfer (tremendously improved by Chandresekhar 1950, though it existed more or less for the previous century)
Punctuated Equilibrium
Recombinant DNA
'Jumping' genes
Prion Theory of Disease
Endosymbiont Origin of Eukaryote Organelles
PCR (Polymerase Chain Reaction)
Cloud physics theory of precipitation
Theory of Data Assimilation (how to use current observations to improve understanding of prior conditions in order to make a better prediction)
Theory of the Ventilated Thermocline
Stommel and Arons theory of the Abyssal circulation
Plate Tectonics
Confocal and two-photon microscopy
Satellites
Weather
Communications

Scientific laws
Scientific laws are similar to scientific theories in that they are principles which can be used to predict the behavior of the natural world. Both scientific laws and scientific theories are typically well-supported by observations and/or experimental evidence. Usually scientific laws refer to rules for how nature will behave under certain conditions.[7] Scientific theories are more overarching explanations of how nature works and why it exhibits certain characteristics.

A common misconception is that scientific theories are rudimentary ideas that will eventually graduate into scientific laws when enough data and evidence has been accumulated. This is not true, as scientific theory and scientific law have different definitions. A theory does not change into a scientific law with the accumulation of new or better evidence. A theory will always remain a theory, a law will always remain a law. A theory will never become a law, and a law never was a theory.