The history of physics tries to recall the origin and the evolution of the ideas, the methods, the men and knowledge of physical sciences.

The physicists are often an acute aware of it (Einstein, Heisenberg, Schrödinger, Prigogine, Feynman, etc). The place of physics is paramount besides in the Histoire of sciences, and the epistemology rests largely on its history.

To escape the pure chronology, one can note the overlap of several parallel problems:

• Determinism and physical probabilist; Laplace hardly conceived the project of mechanist a total explanation of the Nature --a tradition which will culminate with Einstein --, that Fourier is interested in the heat transfers, opening a way which will escape from it completely
• steady balance and turbulences; until the 20th century, physics had been interested in the laws which controlled the states of balances, regarding the dissipative phenomena out of balance as (Entropie); more recently, a new tradition was interested in the phenomena of order far from balance (Prigogine, Maturana)
• objective and Subjectif (or Universalisme and Relativisme): does physics exist apart from any observation of the Nature, or we base it on an idea of experimenter who involuntarily takes part in the phenomenon that he simply thinks of describing? This last point of view, in gestation in the tradition empirist, gained ground with the concepts of relativity (of Galileo, then of Lorentz and Einstein, while passing by strange the Principe of Mach), the Interprétation of Copenhagen in quantum mechanics and the assumption of Everett.
• refutability: are all the concepts of physics well refutable within the meaning of Karl Popper?

Prehistory

During the Prehistory, the men made observations (Stonehenge or Carnac testifies some) and were brought to reproduce Phénomène S. It is on the banks of the rivers Tigre and Euphrate (current Iraq) and of the river the Nile (Egypt), then later in Greece which the first steps of sciences saw the day, 5000 years ago. Those were transmitted by Religieux, which ensured a continuity of the knowledge, navigation ensuring the propagation of the Connaissance S and the writing, on shelves or papyrus, its “storage”.

In the observation of Phenomenon S reproducing in cycles (diurnal, lunar or annual), the discovery of the invariants of these cycles constitutes a scientific beginning of reasoning; there is the concept that the world obeys rules, and that one can probably use these rules.

This period saw the appearance of techniques agrarian, Architecturale S and warlike, the invention of the Métallurgie (Bronze Age in thousand-year-old IIIe front J. - C., age of iron towards 1000 av. J. - C.), the beginning of architecture and mechanics.

Sciences and Religion was mélaient: the craftsmen made prayers during the manufacture of their objects, prayers which could be a means of measuring the Temps when the duration had an importance in the process.

Antiquity

Since the Antiquity, one tried to include/understand the behavior of the matter: why the objects without support fall by ground, why the various materials have different properties, and so on. Characteristics of the Universe, as the form of the Ground and the behavior of the Celestial body S like the the Moon and the Sun were another Mystère. Several theories were proposed to answer these questions. The majority of these answers were false, but that is inherent in the scientific step; and nowadays, even the modern theories like the quantum Mechanical and the relativity are simply regarded as “theories which for the moment were not contradicted” (although they are in their actual position incompatible one with the other).

The physical theories of the Antiquité on the whole were considered from a philosophical point of view, and were not always checked by systematic experiments. It is important here to have Conscience that, in the ancient Greece, philosophy was born from the debates and Discours ( logos ) resulting from the observation of nature ( physikê in Greek). One thus finds the etymology S of much of terms employed today in sciences: suffix - logy (technology,…), and physics.

Physics was considered in the ancient Greece, at the latest at the time of the Stoïcien S, but undoubtedly already before, like one of the three branches of the Philosophie. One did not distinguish it truly from the Métaphysique.

To return to the experimentation, one of them will play a big role: the effect of broken oar which will lead to the study of the refraction . Nevertheless, the idea of experimental method started to be elaborate in a precise way by Epicure and the skeptics, method which will also play a big role in the development of medicine.

Except for precursors like the philosophers of the school milésienne, Démocrite, and well of others, the behavior and the nature of the world were explained by the action of God X. Towards -600 front J. - C., a certain number of Philosophe S Greek S (for example Thalès de Milet) started to admit that the world could be included/understood as the result of process Naturel S. Some took again the dispute of the Mythologie started by this same Démocrite relating to for example the origins of the Mankind. (They anticipated in that the ideas of Charles Darwin -   but that enters rather the Histoire of biology than in that of the Physique.)

For lack of sophisticated experimental material (Telescope S…) and of precise instruments of measurement of the Time, the experimental checking such ideas was difficult if not impossible. There were some exceptions: for example, the Greek thinker Archimedes correctly described the Statique fluids after having noticed one day, if one believes the legend of it, that its own body moved a certain volume of water whereas it entered his bath. Another remarkable example was that of Ératosthène, which - persuaded for other reasons, of which the eclipses of the moon that the Ground was spherical - managed to calculate its circumference by comparing the shadows by vertical sticks in two points far away from the surface of the sphere. It is it should be noted that by applying the result of the same observations to a Ground punt it had deduced the distance from the sun from it, which recalls us that any interpretation is necessarily based on former presuppositions (see Inférence bayésienne).

Greek Mathematician S, whose again Archimedes, thought of calculating the volume of objects like the Sphère S and the cone S by dividing them into imaginary parts infinitely small thickness; what made them precursors, of almost two millenia, of the Integral calculus. But they included/understood badly why one did not converge thus towards the value of $\backslash \; sqrt2$ by dividing the diagonal of the square into small successive stairs !

One knows little about the detail of the old ideas in physics and their experimental checks. The near total of the direct sources with regard to them was lost at the time of the two large fires of the Bibliothèque of Alexandria: -48 with more 40  000 lost rollers, and 696 by the general `Amr Ben Al `Ace who governed the total destruction of the funds (except Aristote whose rollers were saved in extremis and clandestinely by admirors of its works).

The Middle Ages

See also: Science of the Middle Ages

The Moyen-âge was revalued since about thirty years, by historians such as Georges Duby, Jean Favier, Pierre Riché, or Jacques Le Goff.

With the the early Middle Ages, following the Great invasions, the occident forgot part of the heritage of Antiquity, especially the texts of the ancient Greece. Period 550-750 can be qualified obscure times, during which preserved itself despite everything, thanks to Boèce, Cassiodore, Isidore of Seville, and Bède Worthy the, a basic knowledge around the Liberal arts. The Liberal arts formed the basic teaching of the Carolingian schools. However physics did not form part of it.

The Civilization arabo-Moslem woman preserved the memory of Greek science. Principal scientific progresses during the Science of the Middle Ages #Haut Moyen-âge (768-1024) are besides the fact of Arab scientists (mathematical, mechanics, medicine, astronomy) and Indians (mathematics, with the invention of the Zero about the year 500).

The period of the An millet is not this period of legendary terrors, image conveyed by the historians of the XIXe century, like Jules Michelet, but rather a rebirth. A little before the Year millet, some Gerbert d' Aurillac made a stay in Catalonia, from which it brought back scientific knowledge, which made it possible to reintroduce the Quadrivium in occident. This period thus sees the beginning of the installation of mathematical tools (Algèbre, Algorithmique, inter alia) which will be invaluable for the continuation

The physical word appears at the 12th century, in the direction of medicine, science of nature (today: Natural science). Physics corresponded to the one of the treaties of Aristote, which was translated out of the 12th century into Occident. In the philosophy of Aristote, the observation of the Nature holds a great place indeed. In the direction closer to the modern use of the term, one sees progress in the techniques of Architecture (building sites of the Romance and Gothic churches), of navigation. The disciplines are mechanics, the metallurgy, hydraulics, goldsmithery,…

Physics in itself does not seem to have still made decisive progress during this time, except mechanics, and the metallurgy.

Towards the end of the 15th century, the physical word took the direction of science of the natural causes (first use in 1487 according to the Petit Robert), always in philosophy Scolastique.

Rebirth and XVIIe century

The beginnings of the physique with the modern direction undoubtedly go back to Galileo (1564 - 1642), which one can to say that he was the first physicist in the current direction: its faith in Mathématiques to describe the world and the phenomena was what distinguished it from its predecessors, even if one cannot always say that he was a very scrupulous experimenter. Galileo improved optical instruments for astronomy, famous the Telescope, brought decisive progress in Cinématique (uniformly accelerated movement).

The rigor which still missed with Galileo in the mathematical formulation was undoubtedly brought by Descartes: Cartesian Coordinates, work in optics (the law of Descartes is in fact the law of Snell). The famous Discourse on Method , written in French, sought to describe a deductive manner to deal with the problems, much founded on the Intuition. One can say that it marks the beginning of the step of sciences known as “exact”, founded on the reasoning Logique S of Déduction. This step made progress physics in fields like traditional mechanics, optics, differential calculus, the analytical geometry…

Descartes ventured further on the plan Philosophique: in the Meditations on philosophy first (1641), it denounced the science Aristotélicienne, which was guilty not to have included/understood the movement of planets as Copernic and Galileo announced it. The expression Aristotélicien took a very pejorative direction then, to denounce the mistakes of the Scolastique then declining.

Blaise Pascal (1623 - 1662) described the phenomena of Atmospheric pressure, and made many contributions in Hydrostatique and Hydrodynamique. In Mathematical, it invented the Probabilité S, which had applications in physics later on.

Isaac Newton 1643 - 1727 formulated the “laws” which bear its name, which allowed the rise of what is called traditional mechanics. In infinitesimal mathematics, it found a means of raising the indeterminations in the calculation of the tangents or derived. In 1685, it generalized the laws of the gravitation that Robert Hooke had just formulated and used them as bases of its system of the world, where the gravitation, universal attraction force, is the cause of the movement.

Its major work, mathematical Principles of natural philosophy published in 1687, described the Gravitation in a universal and mathematical way. It made it possible to confirm the theory of the Héliocentrisme on the plan of its mathematical formulation (the optical proof was not obtained yet). The methods of calculating that it uses there in make a precursor of the vector calculus. Isaac Newton opened one new era for physics by introducing the differential Calculus for its calculations of Celestial mechanics.

Leibniz (1646 - 1716) invented the Infinitesimal calculus about at the same time as Newton, which developed on its side a similar process with the calculation of the Fluxion S. Its contributions in physics were considerable: the energy, the law of conservation, definitions of space and time, the duality wave-corpuscle.

One can say that it is of this time that the physical word starts to change direction: of science of the natural causes , physics becomes the science which studies the general properties of the matter and establishes laws which give an account of the Phénomène S materials: the first use in this direction goes back to 1708 ( the Petit Robert ).

Industrial era

With Sadi Carnot appears the Thermodynamique, initially to improve the performances of the steam engines. It is the end of the dream of the “Perpetual motion”: a scientific theory establishes now that it is not possible to draw from the energy from nowhere, and that energy “is degraded”. Boltzmann then includes/understands the origin Statistique of the second principle, the only one which reveals a distinction between last and future in physics!

Another very important theory is the electromagnetism, unification of the study of the electricity and the Magnétisme. It is James Maxwell (1831 - 1879) which will finish unifying the two theories, and which will introduce the last terms into the equations which bear its name now and which describe the electric behavior of the fields S and magnetic S. At the time, a observation is made: the Maxwell's equations are not invariant by the Transformations of Galileo. And a controversy makes rage: if the Lumière is a Onde, it moves in a medium, since it is the case for all the waves which one knows. The ether is evoked like assumption for these two problems.

experiments of Michelson and Morley lead however to think that the Speed of light is same whatever the direction, which is in contradiction with the idea of a fixed ether in which the light would be propagated, except if one accepts the assumption of the contraction lengths emitted by Fitzgerald and Lorentz: the Transformation of Lorentz, stated by Fitzgerald (and also by Voigt) in 1889 and independently by Lorentz in 1892. It is especially the experiment of Kennedy-Thorndike who gave the blow of thanks to the concept of ether.

The era of the traditional Mécanique was undoubtedly closed again when the restricted Relativité was discovered, by Albert Einstein, (Henri Poincaré having partially had a presentiment of this theoretical development, very little time before Einstein). This theory, while postulating that the Temps could be relative, put a final point at the debates on the existence of ether, and made it possible to note that the mechanical Newton had only one limited field of validity.

Einstein, continuing in this way, will develop the theory General relativity, with the assistance of David Hilbert by using a very young field of mathematics. This theory will result in explaining the observations of Edwin Hubble, which announces in 1929 that the Galaxie S which surround us move away from our. This observation will lead to the assumption of the beginning of the universe in a great explosion called ironically “Big Bang”.

At the beginning of the 20th century, following work of max Planck and Einstein showing the existence of the Photon (quantum of Light) the greatest conceptual revolution of physics occurred: birth of the quantum Mechanical . This theory put a final term at the golden age of the mechanics of Newton: one approximately considers that this one hardly describes but one small portion of the natural phenomena, those which occur on our scale.

• 1896 : Radioactivity, Antoine Henri Becquerel, France

• 1896: Radium, Pierre and Marie Curie, France
• 1897: electron, Joseph John Thomson, the United Kingdom
• 1898: Polonium, Pierre and Marie Curie, France

The discovery of the Radioactivity and its interpretation occurs at the same time -   the beginning of the 20th century is a succession of scientific discoveries which completely call into question our vision of the universe and the world.

If the radioactivity is discovered by Henri Becquerel, Ernest Rutherford will play a crucial role in the comprehension of this phenomenon: it is him which understands that several radiations are with work (it will call them alpha and beta) and that the radioactivity is accompanied by a transmutation. He also discovers that the Atome S comprise a core, kind of positive seed.

Data-processing era

Any information can be “memorized” thanks to processes of storage, and consultable remotely and in the Temps.

The capacities to store measurements are such as, even if there is not a model to explain a Phénomène, one is increasingly able to follow its evolution “numerically” (see Météorologie for example).

The tools of Informatique scientific and technical should deeply help the Scientifique S and the Engineer S to make reliable the Experimental methods and to eliminate all the pseudo-assumptions which reappear in a recurring way.

However, a problem remains when one uses the Informatique for Usage S of Gestion: compared to the immense quantity of Information S necessary for the development of a product, the evaluation of a market potential, the decision making of the framing, which to choose? Which are the Interaction S with the Partenaire S? How to anticipate?

One is then confronted with questions which raise more of the economic Intelligence physics itself.