Solids

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The solid state is a state of matter characterized by the absence of freedom between molecules or ions (metals for example). The macroscopic criteria of matter in the solid state are: the solid has its own form; the solid has … Read More

Newton’s second law

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Newton’s second law (the fundamental principle of dynamics, or the fundamental relation of dynamics) designates a law of physics relating the mass of an object, and the acceleration it receives if forces are applied to it. We can also see … Read More

Thermal transfer

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A thermal transfer, more commonly called heat, is, along with work, one of the modes of internal energy exchange between two systems: it is a transfer of thermal energy that takes place outside thermodynamic equilibrium. There are three types of … Read More

Unsolved problems in physics, in theory and observations

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This is a list of some of the great unsolved problems in physics. During the long-term process of evolving theories according to the scientific method, there is an intermediary phase between two periods of stability where questions remain unanswered and … Read More

Atomic nucleus

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(Atomic nucleus of helium.) The atomic nucleus refers to the region located in the center of an atom made up of protons and neutrons (nucleons). The size of the nucleus (of the order of a femtometer, ie 10-15 meters) is … Read More

Electromagnetic radiation – Electromagnetic waves

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(Distribution of electromagnetic radiation. ) Electromagnetic radiation refers to a form of linear energy transfer. Visible light is electromagnetic radiation, but is only a small slice of the broad electromagnetic spectrum. The propagation of this radiation, of one or more … Read More

Electricity

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(Power line near a railway track in Poland. ) Electricity is the effect of the movement of charged particles inside a conductive material, under the effect of a potential difference at the ends thereof. This physical phenomenon is present in … Read More

Sound

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Sound is a mechanical vibration of a fluid, which propagates in the form of longitudinal waves thanks to the elastic deformation of this fluid. Human beings, like many animals, experience this vibration through the sense of hearing. Acoustics is the … Read More

Study of mechanics

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  The main principles of mechanics Principle of energy conservation For any physical object with mass, any change in its state results in the expenditure or dissipation of energy. Principle of least action The idea of ​​the principle of least … Read More

Physics disciplines, theories and methods

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Disciplines Contemporary physics research is divided into various disciplines that study different aspects of the physical world. Field(s) Disciplines Main theories Some concepts Astrophysics and Mechanics Cosmology, Planetology, Plasma Physics, Big Bang Astroparticles Big Bang, Cosmic Inflation, General Relativity, Dark … Read More

Heuristics of String Theory

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The logical positivists would have considered string theory as a speculative metaphysics. The instrumentalist aspect of logical positivism does not correspond with the opinions of string theorists. From the point of view of Popper’s falsifiability, [1] we clearly distinguish between … Read More

Epistemology of String Theory in Quantum Gravity

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In quantum field theory, the main obstacle is the occurrence of the untreatable infinities in the interactions of the particles due to the possibility of arbitrary distances between the point particles. Strings, as extended objects, provide a better framework, which … Read More

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