Planck's constant

Planck's constant has units of energy (joules or J) multiplied by time (seconds or s), which are the units of action (joule seconds or J·s). These units may also be written as momentum times distance (newton·metre·second or N·m·s), which are the units of angular momentum. The value of Planck's constant, in joule seconds, is: or, with electronvolts (eV) as the unit of energy: The value of the reduced Planck's constant, in joule seconds, is: See also:

Planck's constant, Planck's constant - Units value and symbols, Planck's constant - Origins of Planck's constant and Dirac's constant, Planck's constant - Usage, Planck's constant - Reference

Read more here: » Planck's constant: Encyclopedia II - Planck's constant - Units value and symbols

Planck's constant has units of energy (joules or J) multiplied by time (seconds or s), which are the units of action (joule seconds or J·s). These units may also be written as momentum times distance (newton·metre·second or N·m·s), which are the units of angular momentum. The value of Planck's constant, in joule seconds, is: or, with electronvolts (eV) as the unit of energy: (The digits in brackets signify the uncertainty (standard deviation) in the last digits of the value). The value of the reduced Planck's constant, in joule seconds, is: See also:

Planck's constant, Planck's constant - Units value and symbols, Planck's constant - Origins of Planck's constant and Dirac's constant, Planck's constant - Usage, Planck's constant - Reference

Read more here: » Planck's constant: Encyclopedia II - Planck's constant - Units value and symbols

Quantum mechanics is a physical science dealing with the behaviour of matter and electromagnetic waves on the scale of atoms and subatomic particles. Since all matter is made of atoms, quantum mechanics is also important in understanding how large objects such as stars and galaxies and even the Big Bang can be analyzed and explained. Quantum mechanical departures from classical physics are most often encountered at small length scales, very low or very high energies, or extremely low temperatures. Quantum mechanics is the basis of mod ...

Including:

• Basics of quantum mechanics - Background
• Basics of quantum mechanics - Old quantum theory
• Basics of quantum mechanics - Planck's constant
• Basics of quantum mechanics - Reduced Planck's constant
• Basics of quantum mechanics - Bohr atom
• Basics of quantum mechanics - Wave-particle duality
• Basics of quantum mechanics - Development of modern quantum mechanics
• Basics of quantum mechanics - Full quantum mechanical theory
• Basics of quantum mechanics - Schrödinger wave equation
• Basics of quantum mechanics - Uncertainty Principle
• Basics of quantum mechanics - Wavefunction collapse
• Basics of quantum mechanics - Eigenstates and eigenvalues
• Basics of quantum mechanics - The Pauli Exclusion Principle
• Basics of quantum mechanics - Dirac wave equation
• Basics of quantum mechanics - Quantum entanglement
• Basics of quantum mechanics - Notes

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Basics of quantum mechanics - Full quantum mechanical theory. Werner Heisenberg developed the full quantum mechanical theory in 1925 at the young age of 23. Following his mentor, Niels Bohr, Werner Heisenberg began to work out a theory for the quantum behavior of electron orbitals. Because electron orbits could not be observed, Heisenberg went about creating a mathematical description of quantum mechanics built on what could be observed, that is, the light emitted from atoms in their atomic spectrum. When a pure ...

See also:

Basics of quantum mechanics, Basics of quantum mechanics - Background, Basics of quantum mechanics - Old quantum theory, Basics of quantum mechanics - Planck's constant, Basics of quantum mechanics - Reduced Planck's constant, Basics of quantum mechanics - Bohr atom, Basics of quantum mechanics - Wave-particle duality, Basics of quantum mechanics - Development of modern quantum mechanics, Basics of quantum mechanics - Full quantum mechanical theory, Basics of quantum mechanics - Schrödinger wave equation, Basics of quantum mechanics - Uncertainty Principle, Basics of quantum mechanics - Wavefunction collapse, Basics of quantum mechanics - Eigenstates and eigenvalues, Basics of quantum mechanics - The Pauli Exclusion Principle, Basics of quantum mechanics - Dirac wave equation, Basics of quantum mechanics - Quantum entanglement, Basics of quantum mechanics - Notes

Read more here: » Basics of quantum mechanics: Encyclopedia II - Basics of quantum mechanics - Development of modern quantum mechanics

Quantum mechanics is a fundamental physical theory that replaces Newtonian mechanics and classical electromagnetism at the atomic and subatomic levels and is the underlying framework of many fields of physics and chemistry, including condensed matter physics, quantum chemistry, and particle physics. Along with general relativity, it is one of the pillars of modern physics. Quantum mechanics - Introduction. The term quantum (Latin, "how much") refers to the discrete units that the theory assign ...

Including:

• Quantum mechanics - Introduction
• Quantum mechanics - Description of the theory
• Quantum mechanics - Quantum mechanical effects
• Quantum mechanics - Mathematical formulation
• Quantum mechanics - Interactions with other scientific theories
• Quantum mechanics - Applications of quantum theory
• Quantum mechanics - Philosophical consequences
• Quantum mechanics - History
• Quantum mechanics - Founding experiments
• Quantum mechanics - Notes

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There is a request, submitted by DaBlade, for an audio version of this article to be created. See WikiProject Spoken Wikipedia for further information. The rationale behind the request is: "This article is very technical, and needs to be explained in an easier to understand fashion for those who aren't very technical within physics. With it being spoken, the speaker can add more general information, to make it more understandable for the not-so physics savvy.". See also: Category ...

Including:

• Zero-point energy - Introduction
• Zero-point energy - What is it?
• Zero-point energy - How do we know it exists?
• Zero-point energy - Is it controversial?
• Zero-point energy - Is it relevant?
• Zero-point energy - A few formulae
• Zero-point energy - Existence
• Zero-point energy - History
• Zero-point energy - Problems and answers
• Zero-point energy - Properties
• Zero-point energy - Cultural references

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Electromagnetic radiation is a propagating wave in space with electric and magnetic components. These components oscillate at right angles to each other and to the direction of propagation. The term electromagnetic radiation is also used as a synonym for electromagnetic waves in general, even if they are not radiating or travelling in free space. This sense includes, for example, light travelling through an optica ...

Including:

• Electromagnetic radiation - Physics
• Electromagnetic radiation - Theory
• Electromagnetic radiation - Properties
• Electromagnetic radiation - Wave model
• Electromagnetic radiation - Particle model
• Electromagnetic radiation - Speed of propagation
• Electromagnetic radiation - Electromagnetic spectrum
• Electromagnetic radiation - Light
• Electromagnetic radiation - Radio waves
• Electromagnetic radiation - Derivation

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Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific context, electromagnetic radiation of any wavelength. The three basic dimensions of light (i.e., all electromagnetic radiation) are: Intensity (or brilliance or amplitude), which is related to the human perception of brightness of the light, Frequency (or wavelength), perceived by humans as the color of the light, and Polarization (or angle of vibration), which is not perceptible by ...

Including:

• Light - Visible electromagnetic radiation
• Light - Speed of light
• Light - Refraction
• Light - Optics
• Light - Color and wavelengths
• Light - Measurement of light
• Light - Light sources
• Light - Theories about light
• Light - Early Greek ideas
• Light - 10th century optical theory
• Light - The 'plenum'
• Light - Particle theory
• Light - Wave theory
• Light - Electromagnetic theory
• Light - Particle theory revisited
• Light - Quantum theory
• Light - Wave-particle duality
• Light - A light wave

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In physics, the photon (from Greek φως "phos", meaning light) is the quantum of the electromagnetic field, for instance light. The term photon was coined by Gilbert Lewis in 1926. The photon is one of the elementary particles. Its interactions with electrons and atomic nuclei account for a great many of the features of matter, such as the existence and stability of atoms, molecules, and solids. These interactions are studied in quantum electrodynamics (QED), which is the oldest pa ...

Including:

• Photon - Symbol
• Photon - Properties
• Photon - Creation
• Photon - Spin
• Photon - Quantum state
• Photon - Molecular absorption
• Photon - Photons in vacuo
• Photon - Photons in matter

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The word quantum, pl. "quanta", comes from the Latin "quantus", for "how much". In general, it refers to an "amount of something". But, the term is often used in the more specific sense which it has in physics, where a quantum refers to an indivisible, and perhaps elementary entity. For instance, a "light quantum", being a unit of light (that is, a photon). In combinations like "quantum mechanics", "quantum optics", etc., it di ...

Including:

• Quantum - Discovery of quantum theory
• Quantum - The quantum black-body radiation formula
• Quantum - The birthday of quantum mechanics
• Quantum - Quantization in antiquity

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Classical physics is physics based on principles developed before the rise of quantum theory, including the special theory of relativity. (In contrast, modern physics refers to the physicist's world view wrought by the revolutionary quantum theory.) There are no restrictions on the application of classical principles, but, practically, the scale of classical physics is the level of isolated atoms and molecules on upwards, including the macroscopic and astronomical realm. Inside the atom and among atoms in a molecule, the laws o ...

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In physics, wave-particle duality holds that light and matter can exhibit properties of both waves and of particles. It is a central concept of quantum mechanics. The idea is rooted in a debate over the nature of light and matter dating back to the 1600s, when competing theories of light were proposed by Christiaan Huygens and Isaac Newton. Through the work of Albert Einstein, Louis de Broglie and many others, it is now established that small objects, such as atoms, have both wave and particle nature, and that quantum mechanics provi ...

Including:

• Wave-particle duality - History
• Wave-particle duality - Huygens and Newton; Earliest theories of light
• Wave-particle duality - Fresnel Maxwell and Young
• Wave-particle duality - Einstein and photons
• Wave-particle duality - De Broglie
• Wave-particle duality - Wave nature of large objects
• Wave-particle duality - Theoretical review
• Wave-particle duality - Applications

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In physics, the de Broglie hypothesis is the statement that all matter has a wave-like nature (wave-particle duality) and that the wavelength and momentum of a particle are related by a simple equation. The hypothesis was advanced by Louis de Broglie in 1923 in his PhD thesis; he was awarded the Nobel Prize for Physics in 1929 for this work. De Broglie hypothesis - The de Broglie equation. The de Broglie equation relates the wavelength to the particle mass and momentum as where:< ...

Including:

• De Broglie hypothesis - The de Broglie equation
• De Broglie hypothesis - Experimental confirmation
• De Broglie hypothesis - Wavelength of large objects

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In physics, the Schrödinger equation, proposed by the Austrian physicist Erwin Schrödinger in 1925, describes the time-dependence of quantum mechanical systems. It is of central importance to the theory of quantum mechanics, playing a role analogous to Newton's second law in classical mechanics. In the mathematical formulation of quantum mechanics, each system is associated with a complex Hilbert space such that each instantaneous state of the system is described by a unit vector in that space. This state vector encodes the p ...

Including:

• Schrödinger equation - Time-independent Schrödinger equation
• Schrödinger equation - Schrödinger wave equation
• Schrödinger equation - The wavefunction
• Schrödinger equation - Operators in the position basis
• Schrödinger equation - Non-relativistic Schrödinger wave equation
• Schrödinger equation - Probability currents
• Schrödinger equation - Solutions of the Schrödinger equation

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In quantum physics, the Heisenberg uncertainty principle states that one cannot assign with full precision values for certain pairs of observable variables, including the position and momentum, of a single particle at the same time even in theory. It furthermore precisely quantifies the imprecision by providing a lower bound (greater than zero) for the product of the standard deviations of the measurements. The uncertainty principle is one of the cornerstones of quantu ...

Including:

• Uncertainty principle - Overview
• Uncertainty principle - Formulation and characteristics
• Uncertainty principle - Expression of finite available amount of Fisher information
• Uncertainty principle - Common observables which obey the uncertainty principle
• Uncertainty principle - The theorem
• Uncertainty principle - Generalizations
• Uncertainty principle - History and interpretations
• Uncertainty principle - The uncertainty principle in popular culture
• Uncertainty principle - Humor

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Through over fifty years of experimentation and applied science, quantum mechanical theory has proven to be very successful and practical. The term "quantum mechanics" was first coined by Max Born in 1924. Quantum mechanics is the foundation for other sciences including condensed matter physics, quantum chemistry, and particle physics. Despite the success of quantum mechanics, it does have some controversial elements. For example, the behaviour of microscopic objects described in quantum mechanics is very different from our everyday e ...

See also:

Basics of quantum mechanics, Basics of quantum mechanics - Background, Basics of quantum mechanics - Old quantum theory, Basics of quantum mechanics - Planck's constant, Basics of quantum mechanics - Reduced Planck's constant, Basics of quantum mechanics - Bohr atom, Basics of quantum mechanics - Wave-particle duality, Basics of quantum mechanics - Development of modern quantum mechanics, Basics of quantum mechanics - Full quantum mechanical theory, Basics of quantum mechanics - Schrödinger wave equation, Basics of quantum mechanics - Uncertainty Principle, Basics of quantum mechanics - Wavefunction collapse, Basics of quantum mechanics - Eigenstates and eigenvalues, Basics of quantum mechanics - The Pauli Exclusion Principle, Basics of quantum mechanics - Dirac wave equation, Basics of quantum mechanics - Quantum entanglement, Basics of quantum mechanics - Notes

Read more here: » Basics of quantum mechanics: Encyclopedia II - Basics of quantum mechanics - Background

Wavenumber in most physical sciences is a wave property inversely related to wavelength, having units of inverse length (radians per meter). Wavenumber is the spatial analogue of angular frequency. Application of a Fourier transformation on data in the time domain yields a frequency spectrum; applied on data in the spatial domain (data as a function of position) yields a spectrum as a function of wavenumber ...

Including:

• Wavenumber - Circular wavenumber
• Wavenumber - Wavenumber
• Wavenumber - Atmospheric science

Read more here: » Wavenumber: Encyclopedia - Wavenumber

edit Einstein's general theory of relativity was introduced in 1915. Physicists accepted the theory because it correctly accounted for the precession of the perihelion of Mercury, a phenomenon which had long baffled physicists and because it unified Newton's law of universal gravitation with special relativity in a conceptually simple way. (Einstein has been famously quoted as saying that if his theory was falsified, then he would have felt "sorry for the dear Lord.") Despite Einstein's proposal of three classical te ...

Including:

• Tests of general relativity - Classical tests
• Tests of general relativity - Modern tests
• Tests of general relativity - Post-Newtonian tests of gravity
• Tests of general relativity - The equivalence principle
• Tests of general relativity - Strong field tests
• Tests of general relativity - Cosmological tests

Read more here: » Tests of general relativity: Encyclopedia - Tests of general relativity

H is the eighth letter of the Latin alphabet. Its name in English is aitch. In the International Phonetic Alphabet, this symbol is used to represent two sounds. Its lowercase form, [h], represents the voiceless glottal fricative, and its small capital form, [ʜ], represents the voiceless epiglottal fricative. H - History. The Semitic letter ח (khêt) probably represented the voic ...

Including:

• H - History
• H - Usage in English
• H - Usage in French
• H - Usage in German
• H - Alternative representations
• H - Computing
• H - Meanings for H

Read more here: » H: Encyclopedia - H

In physics, absolute zero is a fundamental lower bound on the temperature of a macroscopic system. It is an infinite number of orders of magnitude below any attainable temperature. It is by definition unachievable (after all, T appears in the denominator of many equations of thermodynamics), but its existence as a limit has been inferred from extrapolation from observed physical phenomena and from kinetic theory. Today it is defined as the temperature at which all (classical mechanical) motion of particles would cease -- in fact even at absolute zero some sort of motion would remain (helium is predicte ...

Including:

• Absolute zero - History
• Absolute zero - Kinetic theory
• Absolute zero - Cryogenics
• Absolute zero - Thermodynamics and Absolute Zero
• Absolute zero - Absolute temperature scales
• Absolute zero - Negative temperatures

Read more here: » Absolute zero: Encyclopedia - Absolute zero