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{{T|inglese|fisica|ottobre 2011}}
L<nowiki>'</nowiki>'''esperienza di Eötvös''' fu un famoso esperimento della [[fisica]] della fine del [[XIX secolo]] che misurò la correlazione tra [[massa inerziale]] e [[massa gravitazionale]], dimostrandone l'equivalenza con una precisione fino ad allora impossibile da raggiungere.
 
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== Collegamenti esterni ==
* {{en}} L. Bod, E. Fischbach, G. Marx e Maria Náray-Ziegler, [http://www.kfki.hu/~tudtor/eotvos1/onehund.html One hundred years of the Eötvös experiment]
 
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{| class="wikitable"
||'''Class'''
||'''Invariance'''
||'''Conserved quantity'''
|-
||Proper orthochronous<BR>Lorentz symmetry
||translation in time<BR>&#160; <SMALL>(homogeneity)</SMALL>
||energy
|-
||
||translation in space<BR>&#160; <SMALL>(homogeneity)</SMALL>
||linear momentum
|-
||
||rotation in space<BR>&#160; <SMALL>(isotropy)</SMALL>
||angular momentum
|-
||Discrete symmetry
||P, coordinates' inversion
||spatial parity
|-
||
||C, charge conjugation
||charge parity
|-
||
||T, time reversal
||time parity
|-
||
||CPT
||product of parities
|-
||Internal symmetry<P>(independent of<BR>spacetime coordinates)
||U(1) gauge transformation
||electric charge
|-
||
||U(1) gauge transformation
||lepton generation number
|-
||
||U(1) gauge transformation
||hypercharge
|-
||
||U(1)<SUB>Y</SUB> gauge transformation
||weak hypercharge
|-
||
||U(2) [U(1)xSU(2)]
||electroweak force
|-
||
||SU(2) gauge transformation
||isospin
|-
||
||SU(2)<SUB>L</SUB> gauge transformation
||weak isospin
|-
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||PxSU(2)
||G-parity
|-
||
||SU(3) "winding number"
||baryon number
|-
||
||SU(3) gauge transformation
|| quark color
|-
||
||SU(3) (approximate)
||quark flavor
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||S((U2)xU(3))<BR>[U(1)xSU(2)xSU(3)]
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|-
|}
 
Beryllium-magnesium and beryllium-titanium test mass contrasts respectively give 0.1919% and 0.2398% difference/average nuclear binding energies. Beryllium-magnesium gives 0.2397% difference/average baryon number divergence. These are among the largest net active mass composition Eötvös experiments possible. 420+ years of Equivalence Principle tests have given zero net output within experimental error. The largest possible amplitude Eötvös experiment is a parity Eötvös experiment - challenging spacetime geometry with test mass geometry.
 
{| class="wikitable"
||'''Test Masses' Divergent Property'''
||'''Fraction of Rest Mass'''
|-
||rest mass
||<DIV ALIGN="center">100%</DIV>
|-
||crystal lattice<BR>geometric parity
||99.9726%<SUP>a</SUP> alpha-Quartz<BR>99.9771%<SUP>a</SUP> Cinnabar
|-
||nuclear binding energy (low ''Z'')
||00.76% (<SUP>4</SUP>He)
|-
||neutron versus proton mass
||00.14%
|-
||electrostatic nuclear repulsion
||00.06%
|-
||electron mass
||00.03%
|-
||unpaired spin mass
||00.005% (<SUP>55</SUP>Mn<SUP>b</SUP>)
|-
||nuclear antiparticle exchange
||00.00001%
|-
||Weak Force interactions
||00.0000001%
|-
||Gravitational binding energy,<BR>Nordtvedt effect and<BR>lunar laser ranging
||00.000000046% Earth<SUP>c</SUP><BR>00.0000000019% Moon
|-
|}
<SUP>a</SUP>(nuclear mass)/(atomic mass), corrected for isotopic abundance<BR>
<SUP>b</SUP>globally aligned undecatiplet<BR>
<SUP>c</SUP>iron core rather than homogeneous body
 
Chemically identical, opposite parity mass distributions have never been tested in an Eötvös experiment. Do metaphoric left and right shoes vacuum free fall along identical trajectories? A parity Eötvös experiment opposes crystallographic opposite parity space groups P3<SUB>1</SUB>21 (right-handed screw axes) and P2<SUB>2</SUB>21 (left-handed screw axes) cultured alpha-quartz (average atomic weight = 20.03) or cinnabar (average atomic weight = 116.33) solid single crystal spheres or other solid convex shapes with all identical moments of inertia (no directional bias).
 
General relativity (postulated) and string theory (BRST invariance demanded) require parity Eötvös experiment zero net output. Affine ([[Einstein-Cartan theory]]), [[teleparallelism]] (Weitzenböck), and noncommutative ([[Connes]]) gravitation theories predict measurable parity Eötvös experiment output. If the vacuum is reproducibly demonstrated to contain a chiral anisotropic background then angular momentum need not be conserved for opposite parity mass distributions (Noether's theorem). Lorentz invariance would be broken.
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Estratto da "https://it.wikipedia.org/wiki/Esperienza_di_Eötvös"