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Exchange force may refer to:

Exchange interaction, an interaction mediated by exchange particles
Exchange interaction, a magnetic interaction arising from the exchange symmetry between identical particles

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+'''Exchange force''' may refer to:
-In [[physics]] the term '''exchange force''' has been used to describe two distinct concepts which should not be confused.
+* Exchange interaction, an interaction mediated by [[exchange particle]]s
+* [[Exchange interaction]], a magnetic interaction arising from the exchange symmetry between identical particles
-==Exchange of force carriers in particle physics==
-{{Main|Force carrier}}
-The preferred meaning of '''exchange force''' is in [[particle physics]], where it denotes a force produced by the exchange of [[force carrier]] particles, such as the [[electromagnetic force]] produced by the exchange of [[photon]]s between [[electron]]s and the [[strong force]] produced by the exchange of [[gluons]] between [[quarks]].<ref>{{cite book | last = Gribbin | first = John  | title = Encyclopedia of Particle Physics | publisher = Simon & Schuster | year = 2000 | isbn = 0684863154}}</ref><ref>[http://hyperphysics.phy-astr.gsu.edu/hbase/forces/exchg.html Exchange Forces], HyperPhysics, [[Georgia State University]], accessed June 2, 2007.</ref>   The idea of an exchange force implies a continuous exchange of particles which accompany the interaction and transmit the force, a process that receives its operational justification through the [[Heisenberg uncertainty principle]].<ref>{{cite journal | last1 = Falkoff | first1 = David | year = 1950 | title = Exchange Forces | url = | journal = American Journal of Physics | volume = 18 | issue = | page = 30 }}</ref>
-===History===
-One of the earliest uses of the term ''interaction'' was in a discussion by [[Niels Bohr]] in 1913 of the interaction between the negative [[electron]] and the positive [[Atomic nucleus|nucleus]].<ref>{{cite journal | author=Niels Bohr | title=On the Constitution of Atoms and Molecules (Part 1 of 3) | journal=Philosophical Magazine | year=1913 | volume=26 | pages=1–25 | url=http://dbhs.wvusd.k12.ca.us/webdocs/Chem-History/Bohr/Bohr-1913a.html}}</ref>  Exchange forces were introduced by [[Werner Heisenberg]] (1932) and [[Ettore Majorana]] (1933) in order to account for the saturation of [[binding energy]] and of [[nuclear density]].<ref>{{cite journal | doi = 10.1007/BF01342433 | title = Über den Bau der Atomkerne. I | year = 1932 | last1 = Heisenberg | first1 = W. | journal = Zeitschrift für Physik | volume = 77 |issue=1–2| pages = 1–11 }}</ref><ref>{{cite journal | last1 = Majoranan | first1 = Ettore | year = 1933 | title = Uber die Kerntheorie | url = | journal = Zeitschrift für Physik | volume = 82 | issue =3–4 | page = 137–145 |bibcode=1933ZPhy...82..137M | doi= 10.1007/BF01341484}}</ref>  This was done in analogy to the quantum mechanical theory of [[covalent bond]]s, such as exist between two hydrogen atoms in the hydrogen molecule wherein the chemical force is attractive if the wave function is symmetric under exchange of coordinates of the electrons and is repulsive if the wave function is anti-symmetric in this respect.<ref>{{cite book | last = Jammer | first = Max  | title = Concepts of Force | publisher = Dover Publications, Inc. | year = 1957 | isbn=048640689X}}</ref>
-==Exchange interaction and quantum state symmetry==
-{{Main|Exchange interaction}}
-As another, entirely distinct, meaning of '''exchange force''', it is sometimes used <ref>For example, pp. 87&ndash;88, ''Driving Force: the natural magic of magnets'', James D. Livingston, Harvard University Press, 1996.  ISBN 0674216458.</ref> as a synonym for the [[exchange interaction]], between electrons which arises from a combination of the [[identical particles|identity of particles]], [[exchange symmetry]], and the [[electrostatic]] force.
-To illustrate the concept of exchange interaction, any two [[electron]]s, for example, in the universe are considered [[identical particles|indistinguishable]] particles, and so according to quantum mechanics in 3 dimensions, every particle must behave as a [[boson]] or a fermion.  In the former case, two (or more) particles can occupy the same [[quantum state]] and this results in a lack of exchange interaction between them; in the latter case, the particles can not occupy the same state according to the [[Pauli exclusion principle]].  From [[Quantum field theory]], the [[spin-statistics theorem]] demands that all particles with [[half-integer]] [[spin (physics)|spin]] behave as fermions and all particles with [[integer]] spin behave as bosons.  Thus, it so happens that all electrons are fermions, since they have spin 1/2.
-As a mathematical consequence, fermions exhibit strong repulsion when their wave functions overlap, but bosons do not.  This repulsion is what the exchange interaction models.  Fermi repulsion results in "stiffness" of fermions.  That is why atomic matter, is "stiff" or "rigid" to touch.  Where [[wave functions]] of electrons overlap, Pauli repulsion takes place. The same is true for [[protons]] and [[neutrons]] where due to their larger mass, the rigidity of baryons is much larger than that of electrons.
 == See also ==
 *[[Exchange symmetry]]
 *[[Fundamental interaction]]
+*[[Holstein–Herring method]]
-*[[Holstein-Herring Method]]
-==References==
-<references/>
-==External links==
-*[http://www.fkf.mpg.de/keimer/Lecture/Magnetism/Magnetism_3.pdf Exchange Interaction] (PDF)
-*[http://wpage.unina.it/mdaquino/PhD_thesis/main/node7.html Exchange Interaction and Energy]
-*[http://www.cmp.liv.ac.uk/frink/thesis/thesis/node68.html Exchange Interaction and Exchange Anisotropy]
+{{disambiguation}}
-[[Category:Physics]]
-[[Category:Pauli exclusion principle]]