In physics, a quantum (pl.: quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. Quantum is a discrete quantity of energy proportional in magnitude to the frequency of the radiation it represents. The fundamental notion that a property can be "quantized" is referred to as "the hypothesis of quantization". This means that the magnitude of the physical property can take on only discrete values consisting of integer multiples of one quantum. For example, a photon is a single quantum of light of a specific frequency (or of any other form of electromagnetic radiation). Similarly, the energy of an electron bound within an atom is quantized and can exist only in certain discrete values. Atoms and matter in general are stable because electrons can exist only at discrete energy levels within an atom. Quantization is one of the foundations of the much broader physics of quantum mechanics. Quantization of energy and its influence on how energy and matter interact (quantum electrodynamics) is part of the fundamental framework for understanding and describing nature.
Etymology and discovery
The word quantum is the neuter singular of the Latin interrogative adjective quantus, meaning "how much". "Quanta", the neuter plural, short for "quanta of electricity" (electrons), was used in a 1902 article on the photoelectric effect by Philipp Lenard, who credited Hermann von Helmholtz for using the word in the area of electricity. However, the word quantum in general was well known before 1900, e.g. quantum was used in E. A. Poe's Loss of Breath. It was often used by physicians, such as in the term quantum satis, "the amount which is enough". Both Helmholtz and Julius von Mayer were physicians as well as physicists. Helmholtz used quantum with reference to heat in his article on Mayer's work, and the word quantum can be found in the formulation of the first law of thermodynamics by Mayer in his letter dated July 24, 1841.
In 1901, Max Planck used quanta to mean "quanta of matter and electricity", gas, and heat. In 1905, in response to Planck's work and the experimental work of Lenard (who explained his results by using the term quanta of electricity), Albert Einstein suggested that radiation existed in spatially localized packets which he called "quanta of light" ("Lichtquanta").
The concept of quantization of radiation was discovered in 1900 by Max Planck, who had been trying to understand the emission of radiation from heated objects, known as black-body radiation. By assuming that energy can be absorbed or released only in tiny, differential, discrete packets (which he called "bundles", or "energy elements"), Planck accounted for certain objects changing color when heated. On December 14, 1900, Planck reported his findings to the German Physical Society, and introduced the idea of quantization for the first time as a part of his research on black-body radiation. As a result of his experiments, Planck deduced the numerical value of h, known as the Planck constant, and reported more precise values for the unit of electrical charge and the Avogadro–Loschmidt number, the number of real molecules in a mole, to the German Physical Society. After his theory was validated, Planck was awarded the Nobel Prize in Physics for his discovery in 1918.
Quantization
While quantization was first discovered in electromagnetic radiation, it describes a fundamental aspect of energy not just restricted to photons. In the attempt to bring theory into agreement with experiment, Max Planck postulated that electromagnetic energy is absorbed or emitted in discrete packets, or quanta.
See also
- Graviton
- Introduction to quantum mechanics
- Magnetic flux quantum
- Particle
- Photon polarization
- Qubit
- Quantum cellular automata
- Quantum channel
- Quantum chromodynamics
- Quantum cognition
- Quantum coherence
- Quantum computer
- Quantum cryptography
- Quantum dot
- Quantum electronics
- Quantum entanglement
- Quantum fiction
- Quantum field theory
- Quantum lithography
- Quantum mechanics
- Quantum mind
- Quantum mysticism
- Quantum number
- Quantum optics
- Quantum sensor
- Quantum state
- Quantum suicide and immortality
- Quantum teleportation
References
- Wiener, N. (1966). Differential Space, Quantum Systems, and Prediction. Cambridge, Massachusetts: The Massachusetts Institute of Technology Press
- Rovelli, Carlo (January 2017). Reality is not what it seems: the elementary structure of things. Translated by Carnell, Simon; Segre, Erica (1st American ed.). New York, New York: Riverhead Books. pp. 109–130. ISBN 978-0-7352-1392-0.
- E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898. Archived 2017-06-30 at the Wayback Machine
- E. Helmholtz, Robert Mayer's Priorität Archived 2015-09-29 at the Wayback Machine (in German)
- Herrmann, Armin (1991). "Heimatseite von Robert J. Mayer" (in German). Weltreich der Physik, Gent-Verlag. Archived from the original on 1998-02-09.
- Planck, M. (1901). "Ueber die Elementarquanta der Materie und der Elektricität". Annalen der Physik (in German). 309 (3): 564–566. Bibcode:1901AnP...309..564P. doi:10.1002/andp.19013090311. Archived from the original on 2023-06-24. Retrieved 2019-09-16 – via Zenodo.
- Planck, Max (1883). "Ueber das thermodynamische Gleichgewicht von Gasgemengen". Annalen der Physik (in German). 255 (6): 358–378. Bibcode:1883AnP...255..358P. doi:10.1002/andp.18832550612. Archived from the original on 2021-01-21. Retrieved 2019-07-05 – via Zenodo.
- Einstein, A. (1905). "Über einen die Erzeugung und Verwandlung des Lichtes betreffenden heuristischen Gesichtspunkt" (PDF). Annalen der Physik (in German). 17 (6): 132–148. Bibcode:1905AnP...322..132E. doi:10.1002/andp.19053220607. Archived (PDF) from the original on 2015-09-24. Retrieved 2010-08-26.. A partial English translation Archived 2021-01-21 at the Wayback Machine is available from Wikisource.
- Max Planck (1901). "Ueber das Gesetz der Energieverteilung im Normalspectrum (On the Law of Distribution of Energy in the Normal Spectrum)". Annalen der Physik. 309 (3): 553. Bibcode:1901AnP...309..553P. doi:10.1002/andp.19013090310. Archived from the original on 2008-04-18.
- Brown, T., LeMay, H., Bursten, B. (2008). Chemistry: The Central Science Upper Saddle River, New Jersey: Pearson Education ISBN 0-13-600617-5
- Klein, Martin J. (1961). "Max Planck and the beginnings of the quantum theory". Archive for History of Exact Sciences. 1 (5): 459–479. doi:10.1007/BF00327765. S2CID 121189755.
- Parker, Will (2005-02-11). "Real-World Quantum Effects Demonstrated". ScienceAGoGo. Retrieved 2023-08-20.
- Modern Applied Physics-Tippens third edition; McGraw-Hill.
Further reading
- Hoffmann, Banesh (1959). The Strange story of the quantum: An account for the general reader of the growth of the ideas underlying our present atomic knowledge (2 ed.). New York: Dover. ISBN 978-0-486-20518-2.
- Mehra, Jagdish; Rechenberg, Helmut; Mehra, Jagdish; Rechenberg, Helmut (2001). The historical development of quantum theory. 4: Pt.1, the fundamental equations of quantum mechanics, 1925-1926 (1. softcover print ed.). New York Heidelberg: Springer. ISBN 978-0-387-95178-2.
- M. Planck, A Survey of Physical Theory, transl. by R. Jones and D.H. Williams, Methuen & Co., Limited., London 1925 (Dover edition 17 May 2003, ISBN 978-0486678672) including the Nobel lecture.
- Rodney, Brooks (14 December 2010) Fields of Color: The theory that escaped Einstein. Allegra Print & Imaging. ISBN 979-8373308427
In physics a quantum pl quanta is the minimum amount of any physical entity physical property involved in an interaction Quantum is a discrete quantity of energy proportional in magnitude to the frequency of the radiation it represents The fundamental notion that a property can be quantized is referred to as the hypothesis of quantization This means that the magnitude of the physical property can take on only discrete values consisting of integer multiples of one quantum For example a photon is a single quantum of light of a specific frequency or of any other form of electromagnetic radiation Similarly the energy of an electron bound within an atom is quantized and can exist only in certain discrete values Atoms and matter in general are stable because electrons can exist only at discrete energy levels within an atom Quantization is one of the foundations of the much broader physics of quantum mechanics Quantization of energy and its influence on how energy and matter interact quantum electrodynamics is part of the fundamental framework for understanding and describing nature Etymology and discoveryThe word quantum is the neuter singular of the Latin interrogative adjective quantus meaning how much Quanta the neuter plural short for quanta of electricity electrons was used in a 1902 article on the photoelectric effect by Philipp Lenard who credited Hermann von Helmholtz for using the word in the area of electricity However the word quantum in general was well known before 1900 e g quantum was used in E A Poe s Loss of Breath It was often used by physicians such as in the term quantum satis the amount which is enough Both Helmholtz and Julius von Mayer were physicians as well as physicists Helmholtz used quantum with reference to heat in his article on Mayer s work and the word quantum can be found in the formulation of the first law of thermodynamics by Mayer in his letter dated July 24 1841 German physicist and 1918 Nobel Prize for Physics recipient Max Planck 1858 1947 In 1901 Max Planck used quanta to mean quanta of matter and electricity gas and heat In 1905 in response to Planck s work and the experimental work of Lenard who explained his results by using the term quanta of electricity Albert Einstein suggested that radiation existed in spatially localized packets which he called quanta of light Lichtquanta The concept of quantization of radiation was discovered in 1900 by Max Planck who had been trying to understand the emission of radiation from heated objects known as black body radiation By assuming that energy can be absorbed or released only in tiny differential discrete packets which he called bundles or energy elements Planck accounted for certain objects changing color when heated On December 14 1900 Planck reported his findings to the German Physical Society and introduced the idea of quantization for the first time as a part of his research on black body radiation As a result of his experiments Planck deduced the numerical value of h known as the Planck constant and reported more precise values for the unit of electrical charge and the Avogadro Loschmidt number the number of real molecules in a mole to the German Physical Society After his theory was validated Planck was awarded the Nobel Prize in Physics for his discovery in 1918 QuantizationWhile quantization was first discovered in electromagnetic radiation it describes a fundamental aspect of energy not just restricted to photons In the attempt to bring theory into agreement with experiment Max Planck postulated that electromagnetic energy is absorbed or emitted in discrete packets or quanta See alsoGraviton Introduction to quantum mechanics Magnetic flux quantum Particle Elementary particle Subatomic particle Photon polarization Qubit Quantum cellular automata Quantum channel Quantum chromodynamics Quantum cognition Quantum coherence Quantum computer Quantum cryptography Quantum dot Quantum electronics Quantum entanglement Quantum fiction Quantum field theory Quantum lithography Quantum mechanics Quantum mind Quantum mysticism Quantum number Quantum optics Quantum sensor Quantum state Quantum suicide and immortality Quantum teleportationReferencesWiener N 1966 Differential Space Quantum Systems and Prediction Cambridge Massachusetts The Massachusetts Institute of Technology Press Rovelli Carlo January 2017 Reality is not what it seems the elementary structure of things Translated by Carnell Simon Segre Erica 1st American ed New York New York Riverhead Books pp 109 130 ISBN 978 0 7352 1392 0 E Cobham Brewer 1810 1897 Dictionary of Phrase and Fable 1898 Archived 2017 06 30 at the Wayback Machine E Helmholtz Robert Mayer s Prioritat Archived 2015 09 29 at the Wayback Machine in German Herrmann Armin 1991 Heimatseite von Robert J Mayer in German Weltreich der Physik Gent Verlag Archived from the original on 1998 02 09 Planck M 1901 Ueber die Elementarquanta der Materie und der Elektricitat Annalen der Physik in German 309 3 564 566 Bibcode 1901AnP 309 564P doi 10 1002 andp 19013090311 Archived from the original on 2023 06 24 Retrieved 2019 09 16 via Zenodo Planck Max 1883 Ueber das thermodynamische Gleichgewicht von Gasgemengen Annalen der Physik in German 255 6 358 378 Bibcode 1883AnP 255 358P doi 10 1002 andp 18832550612 Archived from the original on 2021 01 21 Retrieved 2019 07 05 via Zenodo Einstein A 1905 Uber einen die Erzeugung und Verwandlung des Lichtes betreffenden heuristischen Gesichtspunkt PDF Annalen der Physik in German 17 6 132 148 Bibcode 1905AnP 322 132E doi 10 1002 andp 19053220607 Archived PDF from the original on 2015 09 24 Retrieved 2010 08 26 A partial English translation Archived 2021 01 21 at the Wayback Machine is available from Wikisource Max Planck 1901 Ueber das Gesetz der Energieverteilung im Normalspectrum On the Law of Distribution of Energy in the Normal Spectrum Annalen der Physik 309 3 553 Bibcode 1901AnP 309 553P doi 10 1002 andp 19013090310 Archived from the original on 2008 04 18 Brown T LeMay H Bursten B 2008 Chemistry The Central Science Upper Saddle River New Jersey Pearson Education ISBN 0 13 600617 5 Klein Martin J 1961 Max Planck and the beginnings of the quantum theory Archive for History of Exact Sciences 1 5 459 479 doi 10 1007 BF00327765 S2CID 121189755 Parker Will 2005 02 11 Real World Quantum Effects Demonstrated ScienceAGoGo Retrieved 2023 08 20 Modern Applied Physics Tippens third edition McGraw Hill Further readingHoffmann Banesh 1959 The Strange story of the quantum An account for the general reader of the growth of the ideas underlying our present atomic knowledge 2 ed New York Dover ISBN 978 0 486 20518 2 Mehra Jagdish Rechenberg Helmut Mehra Jagdish Rechenberg Helmut 2001 The historical development of quantum theory 4 Pt 1 the fundamental equations of quantum mechanics 1925 1926 1 softcover print ed New York Heidelberg Springer ISBN 978 0 387 95178 2 M Planck A Survey of Physical Theory transl by R Jones and D H Williams Methuen amp Co Limited London 1925 Dover edition 17 May 2003 ISBN 978 0486678672 including the Nobel lecture Rodney Brooks 14 December 2010 Fields of Color The theory that escaped Einstein Allegra Print amp Imaging ISBN 979 8373308427
